Alpen Climbing Higher With Two Big Announcements

One of our long-time product partners, Alpen High Performance Products (Alpen), has been making headlines recently, and we couldn’t be more excited! Alpen recently shared news of receiving a substantial grant of $5.8 million from the United States Department of Energy (DOE). This funding is part of a broader DOE initiative, allocating $275 million to seven companies to enhance domestic supply chains and expedite clean energy manufacturing. Alpen also announced they are welcoming a new CEO, Andrew Zech, as longtime leader Brad Begin moves to the chairman role. Both of these announcements signal new changes for the company as they make moves to grow and scale!

DOE Grant Recipient

This DOE grant is a testament to Alpen’s dedication to manufacturing high-performance windows and doors. They’ve worked steadily for years to provide the best in high-performance glass, so it’s refreshing to see them receive such a great honor in the form of this grant! The New York Times reported that the DOE’s program plans to distribute $275 million to seven projects in its initial round, with expectations of attracting approximately $600 million more in private investment. 

Alpen anticipates the creation of over a hundred new jobs as a result of this funding, providing enhanced opportunities for Alpen’s diverse workforce. Alpen also announced the opening of a new facility in Vandergrift, PA, to better serve the eastern half of the United States and allow for increased capacity. Alpen aims to continue leading the way in comfort, efficiency, and environmental sustainability.

The Office of Manufacturing and Energy Supply Chains’ (MESC) report indicates that Alpen’s production is expected to increase tenfold, generating well-paying jobs through investment in automation while significantly reducing customers’ energy consumption and heating/cooling costs.

“The capabilities unlocked by the DOE grant are staggering. It advances our goal of making the clean energy revolution a good thing for American communities and companies and jobs. The investment will create substantial job growth not just for Alpen but for other companies that supply Alpen.”

– Andrew Zech

About Alpen:

For over forty years, Alpen has been dedicated to transforming the built environment in the United States by designing cutting-edge windows, doors, and architectural glass. They build some of the most energy-efficient window and door products in North America and the world – AND they are right in our backyard. Alpen calls Louisville, CO, home and has provided a unique opportunity to the AE Building Systems’ customers and contractors. Their entire team has always been so supportive of our customers.

AE Building Systems & Alpen:

We’ve been proud partners of Alpen for over 10 years! With a true passion to provide top-of-the-line products and sustainable windows, Alpen was a natural choice for our team. With this new announcement, we’re thrilled to see how they grow and expand, making sustainable and energy-efficient windows even more accessible for our customers. 

If you have questions about your window options, our team would be happy to walk you through the possibilities and help you make the best-educated decision for your next project! Contact our team to walk through any questions or ideas you want to explore! 

Goodbye Gas Line: How the Collins-Ruddy Residence Reduced Their Reliance on Natural Gas

Join us today as we dive into another big update for the Collins-Ruddy residence. Todd Collins and his family have been on a multi-phased journey to retrofit their existing home in Golden, Colorado. They’re on a journey to become as close to net zero as possible, while still maintaining a comfortable environment to live in. Their most recent phase featured literally capping their gas line after replacing their water heater and furnace. Today, we want to take a closer look at the water heater, what drove their decisions, how they approached the update, and how it’s working so far. 

Why Cut the Gas to Your House?

One of their family’s goals was to get to net zero, so they knew cutting out natural gas was eventually in the cards. They have a desire to reduce greenhouse gas emissions and fossil fuel consumption as part of their core values. That meant eliminating all combustion appliances, including their water heater. Eliminating gas reliance makes for a healthier, safer environment, while also removing the variable of fluctuating natural gas prices on their monthly bills. Electric appliances don’t carry risks of carbon monoxide poisoning nor health risks of VOC’s from burning natural gas.  Without gas entering the house, there is now no need for even carbon monoxide detectors.

Also, natural gas prices increased significantly during the last two winters, and now the Collins-Ruddy residence is not at the mercy of global demand for natural gas. Instead, they are more reliant on their own solar production of electricity as well as the more local costs for on-grid electricity. All in all, there was a compelling argument to kick that water heater to the curb! 

Timing These Heat Pump Upgrades

Their water heater was already approaching its end of life, so part of the timing here was strategic. They wanted to be prepared, rather than be dealing with an emergency situation. The old water heater was manufactured in 2005, making it roughly 18 years old. They knew it could peter out at any point leaving them stranded without hot water, which is no fun, and especially problematic in the winter months in Colorado. Better to replace in advance of a failure!

Strategically Shifting the Water Heater Location for Better Performance

One thing most people think about is replacing the appliance itself, but not many consider relocating the hot water heater to a more strategic location in the home to eliminate heat loss. In the Collins-Ruddy home, they relocated the tank directly below the kitchen and baths, reducing the length of pipes by about 20-25 feet. As a result, there is significantly less heat loss as the hot water travels from the tank to the faucets. In addition, rather than waiting 30-35 seconds for hot water at the kitchen sink, they now wait about 6 seconds with the new placement.

What Now? 

After ditching the 40 gallon gas-powered water heater, they switched to a 66 gallon A.O. Smith 66-gallon all-electric Heat Pump Water Heater. While it is larger, it is incredibly well insulated. Should the power go out, it only loses 1.5 degrees per day. As a whole, they’ve been extremely happy with the solution. However, Todd shared how the new water heater takes heat from the ambient air around the unit and puts that heat into the water. As a result, the area around the water heater is noticeably colder while it is running. While running, the air temperature can drop between three and five degrees fahrenheit. They’ve learned the goal is to run it low and slow and note that the recovery time depends on what mode you have it on. So far, their family with two teenagers and two adults has been able to operate well on the heat pump only mode and with this amount of hot water. (Of course, keep in mind they’ve already done some things to improve water efficiency in their home including low-flow faucets.) 

The update to the water heater was phase III of this multi-step approach to retrofitting their home in Colorado. The Collins-Ruddy residence still has a ways to go to get to net zero, but with each small step, they are improving the energy efficiency of their home while improving their own quality of life and well-being. We love the idea of building a passive house design from scratch, but that’s just not a reality for most homeowners. Most find themselves in a similar situation to Todd and his family, retrofitting an existing home to be more comfortable, more sustainable, and more efficient all around. 

Are you remodeling and want to geek out over how to make your own project more sustainable? Call up our team for a chat. We love sharing what’s working in our own homes, as well as those of our customers.
Did you catch the retrofit phase I and phase II? Read the full story!

The Yeti is in the Details: Window Spacers

You may have heard the devil is in the details, but when it comes to ice buildup on a cold window, we know it’s probably more fitting for the abominable snowman. Have you ever wondered why ice forms around the edges of your windows on a cold day first? You may look at a window and not even realize the spacer inside of the window is playing such a large role. The spacer is the thermal bridge in the insulated glazing unit (IGU) and overall window, and therefore, the material choice for this often overlooked part is extremely important.

What Role Does a Window Spacer Play?

A spacer is the piece within the IGU that holds the panes of glass apart from each other. A double-pane window will have just one spacer between the two panes of glass, while a triple-pane window has two spacers. There are even quad-pane windows that will have three spacers with four panes of glass. The window spacer should be analyzed in order to prevent condensation (or ice) from forming on the edge of the glass, as well as decrease in performance of the window or door. 

The Weak Link: Window Spacer

Window spacers are the thermal bridge between the glazing and the rest of the window. While it may seem like a small, insignificant part, it can be a weak link in the overall window design. In the past, lower-cost windows have used aluminum or galvanized steel spacers as these are relatively inexpensive, but if you think about how metal feels in the cold temperatures, you can easily see how these materials aren’t helping with insulation! Surprisingly, these materials are still very prevalent in low-cost window brands today. So, while you may get a better deal upfront, you end up paying more in the long run with higher energy bills. 

A Stronger Option: Warm Edge Spacer

A smarter window choice will utilize a better insulating material for window spacers. Thermally-broken spacers are often referred to as “warm edge spacers.” Our friends at Alpen use a product referred to as a “super spacer,” which is a composite material with enhanced condensation resistance compared to the more traditional metal spacer. These include edge-seal durability, superior argon gas retention, and low conductivity. They use high-quality silicone and a highly breathable flexible foam matrix to improve performance. We’ve done a quick demo showing the difference between a metal spacer and these composite options that explains the difference in a simple manner. 

If you’re looking for an energy-efficient window choice, you can be as educated as possible on the various spots where thermal bridging can occur within your window. It pays to get some broad information about the products you are considering so you can compare what one brand says compared to others. Pay attention to what brands aren’t talking about too! The best way to know what they’re not telling you about is to talk to a few different competitors, or talk to energy nerds like us at AE Building Systems who can break down all the various things to be watching out for if your goal is to get an energy-efficient window option. 

When it comes to energy-efficiency, sometimes the smallest part of a design can have a BIG impact. That’s the case when it comes to window spacers and why we’re so passionate about the tiny details in the products we carry at AE Building Systems. We’re all about providing products that have the same passion for quality and energy-efficiency. It’s core to who we are and how we do business! 

Options for Large Windows in High Wind Load Areas

“It is the great north wind that made the Vikings.” – Scandinavian Proverb

If the great north wind helped make the epic, strong Vikings, it’s no wonder that the wind impacts some of the recent innovations to create better, stronger construction practices! We’re seeing it happen day in and day out with new approaches for fenestration – windows and doors. 

The Challenge

Homeowners increasingly want larger and larger expanses of glass in their homes.  At the same time, municipalities, including Boulder, CO, have realized that due to climate change, wind speeds have increased. As a result, Building Departments have increased the required Design Pressure (DP) ratings for windows and doors. The DP rating represents a building component’s ability to withstand a given amount of wind load.

And the challenge is not simple because the wind loads vary based on numerous things including: is the component closer to the edge of a wall or higher up on the building – e.g. multi-story buildings. In short, wind loads are a bit of a moving target across the building facade.

Additional Challenges

With large glazing assemblies, often windows are mulled together creating hinge points which are weak points in the window assembly. Also, as the size of the assembly increases, the DP rating generally suffers – decreases.  There are ways to increase the strength and DP rating of window assemblies which include adding structural mullions, thicker glass, and/or frame reinforcements.  However, these methods help only so much and eventually additional approaches must be considered – especially since homeowners are increasingly requesting entire window walls. The question becomes … How do we create a window wall with high performance and well insulated assemblies without having to use generally lower performance, more costly, commercial focused, structural storefront, curtain wall and ribbon window technologies?   

Consider Steel Tube, LVL or Lumber posts between the windows and doors

While we are not structural engineers here at AE Building Systems, we have been able to help our customers manage the new DP rating requirements necessary for code by suggesting solutions like leveraging steel tube, LVL, or lumber posts at the breaks in the window assemblies. You might think that it’s going to greatly reduce the performance due to thermal bridging and you’re right. Insulating those posts is critical.

Overview of the Steel Tube/LVL/Lumber Assembly: 

Insulate Strategically

Good design that withstands higher wind loads is possible with this steel tube/LVL/Lumber window surround or vertical posts. In the assembly diagrammed below, double LVL’s are used and then insulated with a block of insulation.  The insulation is then wrapped in break metal.  While a double 2x could also be used, LVLs and steel tube are stronger and more dimensionally stable than say a double 2×4. The use of steel tube and LVL helps minimize the bulkiness/width of sight lines, and these are done on the vertical as vertical posts. Keep in mind that windows at the edge of walls or near corners typically have higher DP or wind-load requirements than those in the center of the wall. Also keep in mind that the width of the steel tube or LVL is an important consideration as ideally the window screw flange (often referred to as nail fin) doesn’t overlap.

Especially if you use the steel tube option, you will have significant thermal bridging, so it’s vital to insulate strategically. The image above shows a fairly small thermal break proud (to the bottom) of the LVLs.  We would suggest a deeper block of insulation and then the brake metal wrap should be designed accordingly. Some builders have used fairly thick blocks of insulation outboard of the LVLs or steel tube – e.g. 3” of foam. As mentioned above, you generally do not want to overlap the screw flanges (nail fins). One option might include increasing the RO just enough to accommodate the flanges without overlapping them. 


  • Large assemblies or even “window walls” using this vertical post approach are possible and meet the wind-load requirements. 
  • Steel Tubes and LVLs can help reduce the bulkiness of vertical posts. 
  • Vertical posts can help reduce the required header size generally required for large expanses of glass.
  • Allows for more design freedom to build creative elements into the design of the home, while still sticking within code parameters. 
  • Allows for smaller glazing assemblies which can more readily be transported without heavy equipment, reducing cost.


  • Requires insulation as the use of the steel tube or heavy lumber can be a significant source of energy loss. It is critical that the design includes an insulation component, and more is better. 
  • This assembly can be more costly and require more labor to build. 

If you find yourself working on a project with tight constraints around wind-load parameters, consider an approach like this. Our team is more than happy to talk through how this works in real life and what considerations you may want to have as you design out this assembly! 

Disclaimer: Please consult your structural engineer when using these concepts.

Going Extinct: Saying Goodbye to Fossil Fuels and Hello to Net-Zero-Energy

Just like the dinosaurs, fossil fuels are going extinct in some communities! We’ve heard it mentioned for years, but many communities are starting to put policies in place to actually reduce the reliance on fossil fuels. Fossil fuel bans are showing up more and more in municipalities and communities around the United States and creating quite the buzz! 

The Fossil Fuel Ban Trend

Cities like Boston and Berkeley, have been more prominent in the news with new building codes to reduce natural gas infrastructure and the associated greenhouse gas emissions that come with fossil fuels. The city of Golden, Colorado is also actively building out new code regulations to reduce the reliance on fossil fuels to operate buildings. 

We’re also seeing sustainable communities on the rise where homeowners actively seek out a net-zero lifestyle. One example of this is the Geos Neighborhood in Arvada where the houses are built with net-zero energy. They are built to take advantage of solar energy, geothermal energy, and even goat energy (weed control!). They’ve shown that it can be done and done in a way that doesn’t hike up construction costs. 

The Challenge

Any change like this is set to ruffle a few feathers from those who are used to doing things the fossil fuel way. The shift toward sustainable industries has always received a fair amount of pushback from those in the fossil fuel industry, as well as those who simply don’t want a change. 

But there are some very real concerns with changing the game for building codes. First, in any of these towns and cities, you are faced with a transition and not a clean switch. You have decades of buildings running off of fossil fuels, so you have to account for the transition where you have both fossil fuels operating as well as cleaner energy, like electric, operating in the same neighborhood – a situation found nearly everywhere. Secondly, many land-locked towns that are largely developed already, like Golden, struggle with solar access. Many towns the size of Golden also struggle with the costs of making a change like this on a large scale. 

Then, you encounter scenarios where fossil fuels still are a dominant need.  Noting that Todd Collins is not a spokesperson for the City of Golden or the City’s Sustainability Board, Todd shares about Golden’s Sustainability Board’s assessment: “We also knew there were industrial, or process energy, situations that posed difficulties. So, we focused our attention on the buildings’ energy consumption- where energy is being used to operate the buildings (including lighting, plug loads, water heating, heating and cooling, etc.).” As a result, Golden is considering a more focused, prescriptive approach while getting immense buy-in from the community and industry experts. Making these types of policy changes is a fairly significant process. 

It’s not a cut-and-dry answer to switching away from fossil fuels. 

The Opportunity:

It’s clear there is an interest by a large portion of homeowners, and there is also a shift in local policy to transition to electrification and away from fossil fuels. It’s also clear that the way to get there is not always simple and easy. 

What’s fun is to see that it IS possible! Seeing communities like Geos Neighborhood pop up and new code requirements arise means we’ll see these norms change. Sustainable solutions will become the standard instead of the exception. It’s an exciting time to be part of change!

As electrification becomes more dominant, high performance becomes a must! We no longer can settle for the inferior construction approaches we’ve put up with for years. Instead, we know that high-performance design, workmanship, materials, and products actually save us in the long run. All of these new code trends have increased the demand on high-performance construction products, especially with windows, doors, and insulation. These and a solid attention to details make a big difference! 

Three Simple Things You Can Do:

You may not live in a community where fossil fuel bans are in place, but you can still do your part as a homeowner to reduce your load on fossil fuels. 

  1. Purchase energy-efficient appliances. Make a sustainable choice at your next appliance purchase, or consider upgrading sooner. 
  2. Go solar. We live in a sunny state making solar panels an easy way to move toward electrification. 
  3. Efficient windows. Make a smart choice when you purchase your windows and doors. Energy-efficiency matters here and can go a long way to reduce your heating and cooling costs, which as a result, reduces your fossil fuel consumption. Your energy bills each month will also thank you! 

Not sure where to start? Our team can help point you in the right direction. Whether you’re building from scratch or retrofitting your home, you can easily reduce your own fossil fuel load with a few simple choices for your home!

Rebuilding with Sustainable Purpose After the Marshall Fire

Two years ago, we watched in horror as the racing winds spread the Marshall Fire faster than anyone could imagine. The location made it all even worse as we saw entire blocks of homes go up in flames. With any tragedy, we all want to help but we often forget about the needs after the dust settles a little bit. However, for the families affected, the journey is a long one, and to this day many families are still in the process of rebuilding. 

At AE Building Systems, we’re proud to be a small part of the rebuild story in Louisville, CO for the Marshall Fire. We are actively working with several builders for products. We’re also actively talking with homeowners to answer questions. And just as the fire came through fast and furious, the rebuild efforts are moving fast too. 

Better Than Before

When you’re faced with the need to rebuild, in many cases you have a blank slate to start over. We all have ideas of what we would do differently in a home, and in this case, many homeowners now have the opportunity to make those ideas a reality. Many want to source products to help cut down on their energy costs, while getting a quality product. We’re seeing many homeowners who just want things done right this time around, especially when it comes to their windows and doors. So many homeowners had just been putting up with builder-grade products in their home, but now are making the priority to get high-quality windows to make their home operate and perform as well as it can. 

More Resilient

Being ready for anything is the name of the game, and so there’s been an interesting focus on rebuilding something that is resilient and that will last. No one wants to go through this again. There’s a clear focus around building homes that can withstand the elements while being fire resistant in the future. The focus on rebuilding has been centered around elements like air-tightness, simple home shapes, enclosed eaves, covered porches/decks, and attention to fuel bridges. Another major consideration is the windows and doors used in construction that can hold up better in extreme heat like nearby fires. Safety AND sustainability have become a bigger player in the conversations. 

There are many resources for architects, builders, and homeowners, and the topics range from designing a more healthy home (air quality!) to a resilient home, to rebates and incentives, and help finding your team! 


Recent climate crises have put sustainability at the forefront of everyone’s minds. Events like the Marshall Fire show us how quickly fires can get out of control in climates like Colorado. We all know we can do our part in sustainability. These rebuilding efforts are a great opportunity to lean into these sustainable goals. 


There are many rebates and incentives available to those rebuilding from the Marshall Fire. They range from equipment rebates, to solar, to other home system rebates and more. It’s worth looking through the links below to view all of the various rebates that could be an option for your rebuild. Many of these allow a home to be built better, and more sustainable than before! 

Resources for those affected by the Marshall Fire:

At AE Building Systems, we’re passionate about building homes that are safer, healthier, and more efficient. But, we’re also passionate about empowering architects, builders, and homeowners to make smarter choices. That starts and ends with education. If you’re in the process of rebuilding from the Marshall Fire, or working on a project in general, we want to help you understand what you’re purchasing and why. You should have full confidence in your decisions and we are happy to help. Please contact us as you’re making decisions!

Upcoming Events for the Sustainable Building Industry

Sustainable Building Events You Won’t Want To Miss

Wanting to get involved in the local conversation around building and sustainability? At AE Building Systems, we’re very active in local and regional conversations, and we believe strongly in the importance of knowing what’s happening in the industry. Education is key, and involvement helps move the needle. Since we have a pulse on so many of the amazing events and resources in this sustainable construction space, we wanted to share some of the best upcoming events as we look into the last half of 2023. 

Four Can’t-Miss Events This Fall

Greenbuild Conference + Expo

Greenbuild’s fall event features their decades-long legacy and longstanding commitment to the green building movement. Their focus is in transforming the built environment to serve, prepare and protect our communities. Greenbuild features four days of fantastic content, innovative speakers, and quality networking. 

September 26 – 29, Washington DC

Learn more

PHN Conference

The Passive House Network Conference is here in Denver this year! As a result, it feels like an exceptional opportunity to experience this renowned conference without the extra work of travel. Join like-minded professionals who all care about expanding the Passive House movement for a more sustainable future. They are featuring 30 sessions over 2.5 days with the most up-to-date industry insights from leading expert professionals. Many sessions also provide AIA and PHI learning credits.

October 3 – 6, 2023, Denver, CO

Learn more

2023 Rocky Mountain Natural Building Conference 

The RMNB Conference is headed back to its roots in Boulder, where the association was originally founded. The event will feature classroom-style presentations and round-tables, “mainstage” keynotes, and outdoor workshops and demonstrations. They also are looking forward to rouse of some natural building projects, as well as time to explore the great city of Boulder. 

October 20 – 22, 2023, Boulder, CO

Learn more

PhiusCon 2023

Hot and humid climates are a huge focus this year, and Houston is a great place for PhiusCon to host! The need for efficient, reliable buildings designed with the grid in mind has never been greater, especially in humid climates. PhiusCon 2023 will be a great opportunity for local practitioners, developers and policymakers to be equipped to build more grid-friendly, healthy communities. Join in to meet local professionals while learning about this regional climate need! 

November 7 – 10, Houston, TX

Learn more

What other events are on your radar? We’re always looking to learn, as well as be part of the conversation. Drop us a comment about where you’re headed this year to be part of the sustainability conversation!

The CSAB Journey with Todd Collins

Todd’s Involvement On Golden’s Community Sustainability Advisory Board

One thing you’ll notice when you get to know the AE Building Systems team is that Todd Collins cares A LOT about sustainable design. He lives and breathes it. So, it’s no wonder he has spread that passion for sustainable building and design into his community interactions where he lives. This time on our blog, we are sharing a personal angle from Todd. We hope you enjoy hearing about his passion and the why behind what he does!

My journey is probably like so many others out there: you find something you’re passionate about and it slowly infiltrates your entire life. I’ve always had an interest in architecture and passive solar design, even though I studied computer science in college. After college, I ended up in sales and marketing roles and later went on to meld some of these interests and sales experience to help build what is now AE Building Systems. I love it! I get to geek out on sustainability and passive house design concepts day in and day out – AND get to help others do it too! 

When we had kids, I started thinking more about the built environment and also started thinking about future generations. I started realizing how so much of what we do is setting them up for failure down the road. Instead, by focusing on performance and climate change, we can work to make things better for future generations. 

As a longtime resident of Golden, Colorado, I started getting involved in the local conversations around sustainability. I started as a member of the Planning Commission (PC) and functioned as a sustainability expert as it relates to buildings. Eventually, I was asked to participate on the Community Sustainability Advisory Board (CSAB) and PC  joint committee in developing the new sustainability code. Having now transitioned to CSAB only, one of my primary focuses is to help complete the new sustainability building code. 

CSAB Considerations

As a member of this joint committee for CSAB, I’ve had a unique perspective on the topic and have been able to understand the issues from varying angles. The City of Golden also hired an outside consulting firm that ran three meetings with approximately 20 participants each to get community feedback. We looked at the energy situation from different perspectives to really work toward a solution that focuses on achieving the goals of a 2019 ordinance passed by the City Council that largely aligns the City with the Parris Accord and the State of Colorado goals. .

One of the more significant constraints is the fact that Golden is a small municipality with limited resources and we knew the processes involved to change and manage the new code could be costly. We also knew there were industrial, or process energy, situations that posed difficulties. So, we focused our attention on facilities where energy is being used to operate the building (including lighting, plug loads, heating and cooling, etc.). 

We also looked at zero, zero-ready, Passive-House, NBI, and other performance-based designs to help mold our energy code recommendations. One big focus of these new codes is a reliance on all-electric and is related to GHG emissions. At the same time, we realized that all-electric isn’t a perfect solution, as some energy production is still using fossil fuels. While Xcel is reducing the percentage of energy produced by fossil fuels, code changes like these will actively reduce that percentage as well. 

Prescriptive vs. Performance:

Our joint committee decided on a performance-based direction due to the fact that performance is modeled. Therefore, the responsibility for doing a model would be placed on applicants vs. the municipality. This reduces the city’s burden for resources to move the code along quickly. We do know there may be some situations that require a more prescriptive requirement in addition to the performance approach. For example, reflective roofs and the heat island effect may need to be addressed down the road. 

Where are we now? 

The current path is still all-electric, NZE and on-site renewables and for all construction types – residential, multi-family and commercial.  In February of 2023, City Council requested additional community feedback, which included three more meetings to discuss challenges with developers and the built community. There have been concerns about buildings over three stories, as well as some for industrial/warehouse buildings and affordable housing. We also know there are some hurdles related to solar access.  The City does not protect solar access rights. In summary, the City has a fair bit of work to do to build out a variance/exception process and to build out the criteria for these scenarios. 

There are still a lot of questions to answer, but I’m excited to be part of the process to help our community move toward more sustainability! 


Note: The views and opinions listed above are specific to Todd Collins and do not necessarily represent official views of the City of Golden. 

Grid Electrification in our Backyard: How Golden, Colorado is Raising the Bar for Sustainability

The high-altitude hamlet of Golden, Colorado is making waves with its initiative to mandate all-electric building construction in 2024. This new construction requirement is aligned with the city’s climate action goals, which aim to achieve 100% renewable energy for heating by 2050. In doing so, Golden is setting the example for other towns and cities as they embrace grid electrification and less reliance on fossil fuels. 

Grid Electrification

Electrification refers to the process of replacing technologies that use fossil fuels (coal, oil, and natural gas) with technologies that use electricity as a source of energy. Many local jurisdictions in the region, including Golden, are taking a hard look at how to retrofit their existing infrastructure to move away from fossil fuels and how to set codes and regulations for future construction. 

Building a Roadmap

The city has already adopted the 2021 national building codes and has identified several initiatives to pursue renewable energy in line with the Paris Agreement. However, the city council is taking another step further. They have directed staff members to continue working on a roadmap but with additional research and public meetings to resolve concerns about a proposed requirement for all New Construction for now.  This requirement includes all-electric, net-zero with on-site renewable generation, that some community members see as problematic.

The efforts to eliminate natural gas from buildings are gaining traction in local communities. Many Colorado jurisdictions are still undecided about whether to ban natural gas or other fossil fuels for space and water heating. Some have decided to lay the groundwork for all-electric without actually raising that bar. In contrast, Crested Butte was the first jurisdiction in the state to ban natural gas for new development, except in special cases like restaurants and certain commercial uses. Golden is gathering intel on all of these use cases to set a roadmap for their guidelines. 

The Golden Challenge

Golden faces a unique challenge as the city is largely developed, which limits new construction primarily to infill or replacement of existing buildings. In the last five years, Golden has had no more than 17 new single-family houses in any given year, and the maximum for one year was eight commercial buildings. Theresa Worsham, the sustainability director for Golden, emphasized that “each community’s needs are likely going to be different, and its decarbonization plans need to be similarly different.”

Four Strategies Toward Electrification & Sustainability

Golden has adopted four strategies to achieve its goals:

One strategy is to require owners of commercial buildings of 5,000 square feet or more to track their emissions. The state now has a similar requirement for buildings 50,000 square feet or more. The idea is to get building owners and managers to understand their emissions, with the potential for instituting programs in the future that may seek to reduce emissions. Among the city’s goals, adopted with the Paris Agreement, is to squeeze energy use in all buildings by 15% through efficiency measures.

The second strategy is to commit the city to further research during 2023 and beyond about how to convert existing buildings toward net-zero all-electric in the coming years. This strategy did not receive much attention during the city council meeting. 

The third strategy is to find ways to address building retrofits. Ken Jacobs, a former member of the sustainability board, suggests that the most effective policy would trigger the net-zero requirement if the remodeling is extensive enough to require new heating systems.

The last and most prominent strategy is the proposed requirement for on-site renewable generation. While it might easily be possible to import all of Golden’s electricity from distant wind and solar farms, the groups concluded that the city has a moral responsibility to generate electricity locally. This also has the advantage of furthering the city’s interest in resilience. The proposed regulation would require that on-site energy storage be deployed or off-site solar via solar gardens located in Golden. The last resort would be to purchase renewable energy credits for renewable energy systems located in Colorado.

A Complex Challenge

It sounds like a great idea, but when you dig into the nuts and bolts of executing requirements like these, you start to see where it becomes a challenge. For a town like Golden, which is largely developed and landlocked, you can easily understand the limitations for access to solar fields or physical space to produce its own energy. There are often added costs to newer technology and infrastructure, as well as new questions and concerns no one has had to think about yet in building code requirements. And, the question of what to do with existing buildings is a challenge as well, posing many to consider if a dual source between fossil fuels and electrification can coincide. 

It’s simply a complex problem. 

Even though it is complex, towns like Golden are willing to tackle it! The benefits of sustainability are obvious, especially when they align with the town’s values. Building an energy ecosystem focused on electrification also allows for greater resilience when one energy source is lagging due to cloudy days, skyrocketing fossil fuel costs, or other hiccups that cause disruption in the energy source availability. 

It’s fun to see a local municipality taking on the challenge! The hope is that other towns in Colorado, and the region, take on the challenge as well. As a result, we’ll see better management of our earth’s resources, greater sustainability, greater resiliency, and greater awareness of how electrification can benefit a community. We’re excited to see how this plays out in our own backyard here in nearby Golden, Colorado!

Passive Solar Design vs Passive House Design: Two Distinct Approaches to Energy Efficiency

Passive is passive, right? 

When someone talks of passive designs, they are pretty much the same, correct? 

While both Passive Solar Design (PSD) and Passive House (PH) may sound similar, they are actually two distinct approaches to design and construction. They often get lumped in the same category, and people can confuse the two easily. They have many similarities and share a few goals and approaches, but they are not exactly the same. Let’s break down a few of the qualities of each. 

Passive House Approach:

A Passive House (or Passivhaus) focuses on a few core principles:

  1. Airtightness: Goal is to build a building as airtight as possible to prevent heat loss through drafts or thermal bridging.
  2. Thermal Boundaries: Goal is to have continuous insulation around the outer perimeter of the building to create a defined thermal boundary. 
  3. HRV Usage: Use a heat-recovery ventilator to allow fresh air into the home without the need to open windows. 
  4. High-Performance Windows & Doors: Special attention goes into the selection of windows and doors to ensure minimal heat loss at these openings. 
  5. Thermal-Bridge Free: While eliminating thermal bridges entirely is likely not possible as there are some tricky areas, the energy modeling accounts for all thermal bridges in the building and minimizing them is critical for meeting PH certification requirements. 

Passive House Design’s approach is focused on heat losses rather than solar gain, and while it may take solar positioning and thermal gains or losses based on the house’s orientation into consideration, that is just part of the equation. Passive House design is focused on minimizing temperature swings for improving comfort within the house. Passive houses don’t rely on the sun to get to their energy-efficiency goals. The solar piece might be like the cherry on top to help a house perform efficiently. 

Passive Solar Approach: 

Passive Solar Design is focused on leveraging the sun to heat and cool a home. The orientation of the home becomes extremely important. Often described as the “glass and mass” approach, the focus is largely on positioning large amounts of glass toward the South to maximize the sun’s warmth, as well as incorporating significant thermal mass to store the sun’s heat which can be released from that thermal mass for hours later. That said, Passive Solar Design considers more than just orientation and thermal mass.  While less important, PSD also considers zoning, shading, insulation, ventilation, and convection concepts. 

Passive Solar Design homes are often designed to operate with minimal (or without any) mechanical cooling or heating, as much as the climate allows. These homes may incorporate airtightness, but that is not the most important focus of the design, as compared to Passive House design. 

Related, But Different: Passive Solar vs. Passive House Design

Based on a quick look, it’s easy to see that both design approaches have a similar goal of creating a more passive approach to energy efficiency and overall comfort in a home. The execution and the core focus, however, are extremely different. Passive Solar is focused on leveraging the sun and mass to achieve this goal, but so much of this approach is based on limiting factors with weather/solar availability, inconsistencies in temperatures, and a less calculated approach. 

Passive House Design focuses on calculated steps to achieve an optimally efficient home with minimal thermal bridging, air leakage, and heat loss. The Passive House Design can more accurately predict the comfortability of a home based on the design, while still accommodating for whatever temperatures are waxing or waning outside. Passive House Design doesn’t discount passive solar concepts (e.g. Mass and Glass) but instead incorporates them within their design as part of optimizing the whole design as a system of systems. 

It’s important for homeowners and designers to understand the subtle differences here. While Passive Solar Design paved the way, in many respects, for the Passive House movement to emerge, Passive Solar often falls short of meeting energy-efficiency goals for homeowners. 

At AE Building Systems, we lean more into the Passive House direction because it IS so much more comprehensive for homeowners who want to build with efficiency in mind. We also see Passive House Design working better in our region here in Colorado where intense sun from a bluebird day can make some PSD homes a hotbox, forcing residents to turn on their air conditioning on a cold day, which is counterproductive! The shoulder seasons of fall and spring when the sun is still lower in the sky can also be quite difficult to regulate. 

Thinking of building a home that is a little more passive, and works FOR you in the long run? Start by talking to our team about how to pursue your goals. We can help point you in the right direction on products, ideas, designers, and more! 

Energy-Minded Design: The Balance Between Form & Function

There are some pretty snazzy design ideas out there in the world. If you look at design contests, architectural school projects, or even just down your own street, you’ll probably see some very beautiful designs that simply don’t make a lot of practical sense. It comes back to the age-old question of form vs. function. Designers have been walking that delicate balance for thousands upon thousands of years, and in today’s world, it’s no different. Simply put: certain design attributes cause complexity with energy efficiency and force project owners to make hard decisions. 

Complex Design Attributes: There are a handful of common design attributes that simply add complexity to the energy efficiency of a house. For someone designing a Passivhaus building, or just wants to be energy-aware, the question usually comes up and you have to decide between bump-outs that make the energy model more challenging and something that will help prevent energy loss.
Design Features: Bump-outs, cantilevered floors, dormers, knee walls, and more are some of the common culprits. Often, these are poorly insulated and add extra exterior wall surface area and seams in a wall or roof construction. All of these factors lead to energy losses due to air infiltration and thermal bridges.

Conditioned Breezeways: Breezeways that are conditioned, heated, and cooled, are another common culprit for energy loss. While these are great for connecting parts of a home, they often have multiple exterior facades, increasing the potential for thermal inefficiency. The surface area to volume ratio is much higher in a breezeway than typically is found in the primary parts of a home. 

Poor Orientation: Orientation of a home is often the last consideration, but especially in sunny climates like Colorado, the way a home faces the sun can make a big difference. Whether you’re dealing with a room overheating or a spot in the home being too cold from lack of direct light (and heat) from the sun, it can make a difference. 

How to Design Well, But Efficiently
Simple is Better: Every time you add a turn, an opening, or additional surface area to the exterior, you increase the potential for energy losses while increasing the complexity of how you will maintain thermal integrity at that juncture. Simplicity allows for higher performance than highly complex building envelopes!

Orient Well: Take note of the orientation from the start. You’ll want to consider your views as well, but keep in mind which side of the home will get the most sunlight and daytime heat. Also, think through where the windows will be positioned in relation to this orientation. It makes a big difference in states like Colorado where the sunlight can cause huge temperature swings for some spaces. 

Materials Matter: If your overall exterior facades are fairly simple, you can still add some elements of great design and interest with the placement of unique finish materials and colors. Breaking up a facade with a few materials and complementary color schemes can add interest without causing extra energy losses. In fact, you can even incorporate these design material choices in a way that supports extra insulation (e.g. continuous insulation). Finish and insulation material selections can help protect a home even more from the harsh sun, wind, or outside temperatures. 
Purposeful Corners: If you are adding complexity to your design with additional corners and bump-outs, make sure you are designing those weak points with intention. Proper design and use of materials to seal off and improve the thermal performance of these junctures is vital!

Exterior Living Spaces: Consider how exterior living spaces like porches, pergolas, and covered patios can allow depth and great design, while strategically protecting the home from energy losses. 

Are we saying your house needs to look boring to be energy-efficient? Absolutely not! Some of the most efficient, sustainable homes we’ve encountered are true works of art. However, an energy-efficient home doesn’t happen by accident. It must be a continual conversation between you, your architect, and your contractor to ensure any and all goals on the project are met. 

As you consider these energy-efficient options for your home, make sure to keep our team involved in the process. We often help our clients find the balance between form and function so that your home is truly the energy-efficient work of art you’ve always dreamed of!

Passion for Sustainability at the Poindexter House

Combine a little bit of personality and A LOT of passion for sustainability and you get an amazing home! The Poindexter/Kavan Project is living proof of this, and we’re thrilled to be a small part of this home’s story. We can’t wait to share this amazing project with you. 

About Amanda and CJ:

Amanda and CJ are a unique couple in that they both have solid construction backgrounds, as well as big passions for sustainability. When you combine their knowledge and passion together, you get amazing energy around a project! 

Amanda has a degree in Construction Management from Colorado State University and has worked for years with her father building homes and learning the trades. She’s worked as a Project Manager for multiple general contractors and finally settled into her own business with Full Circle Construction Services. She also currently consults with the Town of Basalt and runs their Sustainable Building Regulations and helps to implement and enforce the IECC through plan reviews and inspections. Amanda is a HERS Rater, LEED AP, BD+C, an ICC B5 Inspector, and an all-around bad-ass. 

CJ also has a construction background with a degree in Construction Management from Colorado State University and grew up with construction in his blood from his father, who was a home builder. CJ has worked as a Project Engineer for larger commercial contractors in the past. He’s owned his business, Fulcrum Enterprises, for the past 15 years and it has evolved from landscaping and remodeling to currently working as a subcontractor/Project Manager for a land development construction management firm and picks up side projects in construction for fun. 

We think it’s safe to say they are a “power couple” with a passion for building in lasting and energy-efficient ways.

Keys to This Project

Sustainability: Just take a look at their backgrounds and you know it’s a common thread throughout the entire house. However, it wasn’t just a “nice to have” kind of thing; they took it seriously. The net-zero build was a huge priority for them and drove many of the keys in their design. 

All-Electric: The building is all-electric, allowing the energy usage to be offset with onsite solar. Also, Amanda and CJ were able to take advantage of the “Power Plus Program” offered by their local utility, allowing them to install five Tesla batteries. The solar charges the batteries during the day and the house is able to use power from the batteries when the sun goes down. Not to mention, they’ll have power if any outage were to occur. Key word here…resiliency! 

Orientation: The orientation was absolutely key on this project, and the couple says they lucked out to be able to find a lot that not only allows for great orientation (south-facing solar gain and PV orientation), but also one that has a killer view! 

Simple Design: They knew a simple shape was going to be the easiest to keep airtight, so they started with a rectangular shape design. Interesting fact: they didn’t have much of a budget for an architect, so Amanda learned Sketchup to map out the design. The layout was designed by cutting pieces of construction paper to play around with how to arrange the rooms. 

Wall Design: They originally had multiple wall assemblies in mind, but finally settled on a double-wall design due to construction ease. It fit the bill for their budget, while allowing for a high-insulation design without thick exterior continuous insulation. 

Window Design: The couple was intent on a lower u-value and wanted to also support a local business, so they turned to AE Building Systems and Alpen products. The window specifications (and price!) were right on target. They even went and visited the factory to see the product up close, and ended up going with the Tyrol tilt/turn design. It was also a minimal cost to upgrade all of the windows to “tempered,” so they did that to help if there was ever a forest fire in the area. 

Vented Roof Assembly: The couple wanted a vented roof assembly, so they turned to raised heel trusses and blown-in cellulose throughout the home (R40 in the walls and R60 in ceilings!). 

Ventilation: Amanda and CJ did all of their own ductwork, so the system was kept as simple as possible. They went with the Zehnder ERV, allowing every room to have a fresh air supply and every kitchen/bathroom to have an exhaust. The entire system is balanced with an amazing energy recovery rate of 85% in the core! 

Mechanical: The home is heated and cooled with Mitsubishi Hyper Heat mini splits. A non-ducted design was used and there are four zones. In the winter, the Hyper Heat system allows the system to operate at full capacity down to single-digit temperatures and the system is able to operate down to a temperature of -22°F. A heat pump hot water tank was also utilized. 

Air Sealing: This home is close to the 0.60 ACH50 goal and once they finish off their basement, they’re confident they’ll hit that number. Air tightness was one of their top goals, and dictated so many of their decisions from construction techniques down to materials. 

Was it a perfect project from start to finish? Far from it, but the photos speak for themselves: this couple knocked it out of the park! It’s not only a gorgeous home but a high-performing home. We’re confident they’ll make many great memories here, not to mention all of the amazing memories that went into designing and building the home. 


“AE was great! They were so responsive, spent hours with us to give us a tour of the factory before we ordered any windows/doors, and followed up on any and all loose ends that we may have. Thank you!” 

Amanda and CJ were a joy to work with and we’re so glad they had a great experience with our team as well. All of us at AE Building Systems are passionate about sustainability and quality regional products. If you want to geek out over net zero building tactics like Amanda and CJ did, we would love to geek out with you too. 
Want to see even more from this project from start to finish? Check them out on Instagram: @yeticoolerhouse and at their website

The Same, Yet Different: The Key Differences in Window & Door Design from Europe to the United States

So much of our life in the United States is heavily influenced by and similar to Europe. However, one area that has some pretty significant differences is in the design and construction of windows and doors. When you look at how life in Europe evolved and has more mixed-use, urban influences to residential design, as well as some of the climate factors, it makes sense that the focus around window and door design would vary some. 

Window Differences: How European Windows and American Windows Vary

Materials in Windows

While materials are often the same (e.g. wood, vinyl, aluminum, fiberglass, and, of course, glass), the construction of the windows and doors are often different. One of the main differences between European and American windows is thermal breaks and insulation used within the construction. In Europe, windows are typically made from wood, aluminum, or uPVC; these materials are generally more durable and energy-efficient, and they allow for a variety of design options. The “u” in uPVC stands for “unplasticized” which means that the PVC doesn’t expand and contract as much. 

Also, Europeans, and increasingly here in the US, design lots of chambers within the profile that increase structural integrity while reducing conductivity and convection currents with the assembly. The structural stability increases and the sizes can be larger. In European Aluminum windows, the thermal breaks tend to be more substantial and more effective at reducing conduction through the assembly. In contrast, American windows are often made from standard PVC or fiberglass, have less or no insulation, and have smaller, less effective thermal breaks in the aluminum systems. In addition, the spacers are often different. In Europe, they often use a composite spacer between the glass which has lower conductivity whereas in the US, highly conductive metals like aluminum or galvanized steel are often used. While materials might be less costly, many US products are not as energy efficient or as versatile in terms of design.

Installation of Windows

Another key difference between European and American windows is the way they are installed. In Europe, windows are typically installed from the inside of the building with anchor brackets vs. nail fins (preferably called screw fins). This allows for a more secure and energy-efficient installation, as the window can be sealed tightly against the frame. This also allows the windows to “sit” in the middle of the insulation layer boosting the overall wall performance to a small degree. In America, on the other hand, windows are typically installed from the outside of the building. This allows for easier installation, but it can result in gaps around the edges of the window and allows for wind-washing which cools the window and impacts energy efficiency.

Going In or Out

Another difference between European and American windows is their opening and closing. In Europe, windows are often designed to be opened in a variety of ways, including hinged and casement. European casement-style windows often tilt/turn inward with a dual action. See the video below by Todd demonstrating this window operation. This allows for greater flexibility and ventilation. In the United States, on the other hand, windows are typically designed to be opened by sliding or tilting. This is a simpler and more cost-effective design, but it can limit ventilation options. When US casement windows are designed, they typically open outward with a crank handle. 

Focus on Efficiency

Finally, the energy efficiency of European and American windows can vary greatly. In Europe, windows often have a higher focus on energy efficiency, with typically 3 panes of glass and advanced air sealing technology – multipoint locking. This helps to keep heat in during the winter and out during the summer, reducing energy costs and improving the building’s overall energy efficiency. In America, on the other hand, windows are more cost-effective and simple in their design. Sustainability and energy efficiency is growing in popularity but is still working hard to catch up to the efforts that have been standard in much of Europe. 

Come and Knock on My Door

Door design also has a few striking differences between US design and construction compared to European design. 

Sash Clearance: US entry doors have a higher sash clearance at the threshold, whereas European doors have a much smaller sash clearance. Designers should keep the clearances in mind if homeowners want  ¾” wood floors, and then throw rugs. In these cases, the door will need to be installed higher so the door will open.  

Frame/Jambs: US door frames/jambs typically use a 1X for the jambs. Compare this with the European style, which can be bulkier and have a clear opening that is much smaller than US doors. 

Balcony Doors: These style doors are much more common in European design. They typically do not have a low threshold that you might find with an entry door, and, instead have a window frame at the threshold. It’s a more cost-effective way to create a larger opening and allows a large window to act like a door. It’s not ideal in high-traffic areas, but with more compact city living in Europe, you’ll see them on balconies and low-traffic areas. 

Sliding Doors: European sliding doors include a lift slide design, where the handle of the door is actually a lever that lifts the entire sliding portion of the door off of the threshold while pushing rollers down to lift the door. European-style sliding doors also come in a style that includes a tilt/slide but has a high threshold similar to balcony doors. Also, similar to balcony doors, these don’t work well in high-traffic areas. 

We’re starting to see more lines blurred between US and European design. Many of the European features are starting to cross over and impact designs here in the United States. As a result, we’re seeing greater efficiency and performance, lower barriers to entry in cost and availability of designs, and greater ease to build a house with Passivhaus principles! 

At AE Building Systems, we’re devoted to providing the highest quality products, especially when it comes to windows and doors. We’re seeing the trends as they’re changing, and know the differences to help contractors and homeowners make the right decisions when it comes to their product selection. Got questions? We’re always happy to help! 

Love the Home You’re In: LaDuke Residence Remodel

What do you get when you cross a sustainably-minded contractor with a home in deep need of an energy overhaul? You get the LaDuke Residence remodel, and the final product is truly something to admire. Jonathan LaDuke has a passion for green building, and as a contractor by trade, he oversaw this remodel on his own home to help bring it up to a higher energy standard. If you are in the Gunnison area, look Jonathan up if you need assistance with your home or building. 

The house was originally built in 1982 as an all-electric envelope house. The ceiling’s radiant heat was starting to fail and not operating efficiently. However, the house had potential! And Jonathan knew it. The passive solar gain gave the house amazing potential to operate more efficiently, so Jonathan moved to pursue a net zero energy house. 

With Jonathan’s experience as a contractor and extensive knowledge in energy efficiency, he knew he could get the house to where it needed to be. He’s a founding member of an insulation and air sealing company, as well as a certified thermographer. He uses an infrared camera in energy auditing and troubleshooting building science issues. Jonathan definitely knows about energy efficiency! 

As a contractor, working largely in energy efficiency, it felt natural to put his money where his passion lies. Pursuing net zero energy on this house felt like the right thing to do, and an effective use of budget with the long-term in his sights. 

Project Features

Jonathan focused on some key areas of the home to make it function well and reduce energy loss throughout the home. The quantitative analysis was important data to guide his decisions but ultimately the way he wanted to “feel” living in the house was a considerable driving force as well. Here are some of the highlights:

  • Wall Assemblies: All wall assemblies have thermal breaks built into the design by way of Zip-R Panels or double interior walls. R- values range from R-42 – R-60 in the walls with hybrid closed-cell foam and dense-pack cellulose. The roof thermal envelope is an R-70 with loose-fill cellulose.
  • Air Infiltration Mitigation Techniques:  All two or more sistered framing members were caulked for air sealing measures and all windows were extensively air sealed with window foam and/or caulk, as well as any thermal envelope penetrations.
  • High-Efficiency Windows: Alpen Tyrol 625, with the help of AE Building Systems, were used throughout the project, offering higher efficiency and lower thermal loss than the previous builder-grade windows. 

We all want visually beautiful homes, but it is equally important to have a highly functional house that is energy efficient and has healthy indoor air quality. These details are often overlooked and the fashion of our homes eclipses the healthy function of our homes. Always consult professionals in energy efficiency when making building decisions. At AE Building Systems, we’re always available to help consult on the top products to use on your next project. The LaDuke Residence Project is a great example of remodeling and retrofitting a home to increase energy efficiency, and still loving the home you’re already in. 

Love the Home You’re In: LaDuke Residence Remodel

What do you get when you cross a sustainably-minded contractor with a home in deep need of an energy overhaul? You get the LaDuke Residence remodel, and the final product is truly something to admire. Jonathan LaDuke has a passion for green building, and as a contractor by trade, he oversaw this remodel on his own home to help bring it up to a higher energy standard. If you are in the Gunnison area, look Jonathan up if you need assistance with your home or building. 

The house was originally built in 1982 as an all-electric envelope house. The ceiling’s radiant heat was starting to fail and not operating efficiently. However, the house had potential! And Jonathan knew it. The passive solar gain gave the house amazing potential to operate more efficiently, so Jonathan moved to pursue a net zero energy house. 

With Jonathan’s experience as a contractor and extensive knowledge in energy efficiency, he knew he could get the house to where it needed to be. He’s a founding member of an insulation and air sealing company, as well as a certified thermographer. He uses an infrared camera in energy auditing and troubleshooting building science issues. Jonathan definitely knows about energy efficiency! 

As a contractor, working largely in energy efficiency, it felt natural to put his money where his passion lies. Pursuing net zero energy on this house felt like the right thing to do, and an effective use of budget with the long-term in his sights. 

Project Features

Jonathan focused on some key areas of the home to make it function well and reduce energy loss throughout the home. The quantitative analysis was important data to guide his decisions but ultimately the way he wanted to “feel” living in the house was a considerable driving force as well. Here are some of the highlights:

  • Wall Assemblies: All wall assemblies have thermal breaks built into the design by way of Zip-R Panels or double interior walls. R- values range from R-42 – R-60 in the walls with hybrid closed-cell foam and dense-pack cellulose. The roof thermal envelope is an R-70 with loose-fill cellulose.
  • Air Infiltration Mitigation Techniques:  All two or more sistered framing members were caulked for air sealing measures and all windows were extensively air sealed with window foam and/or caulk, as well as any thermal envelope penetrations.
  • High-Efficiency Windows: Alpen Tyrol 625, with the help of AE Building Systems, were used throughout the project, offering higher efficiency and lower thermal loss than the previous builder-grade windows. 

We all want visually beautiful homes, but it is equally important to have a highly functional house that is energy efficient and has healthy indoor air quality. These details are often overlooked and the fashion of our homes eclipses the healthy function of our homes. Always consult professionals in energy efficiency when making building decisions. At AE Building Systems, we’re always available to help consult on the top products to use on your next project. The LaDuke Residence Project is a great example of remodeling and retrofitting a home to increase energy efficiency, and still loving the home you’re already in. 

How do you make change in the world? 

Change happens slowly and in small ways, with every single purchase and every decision we make. As consumers, we each have opportunities to make decisions and at AE Building Systems, we’re at the core of these small, everyday decisions that are making a real difference in our world. But, another way change happens is when we see regulations and laws change. 

The process of making real change for the better has so many other applications outside of sustainability and doing right by our earth. However, we’re beyond thrilled to see recent changes in municipalities throughout the state of Colorado regarding energy efficiency. These are signals to us that change is finally coming on things that used to be mere suggestions now becoming a requirement.

Creating a New Normal

We don’t always think about it being a big deal, but small changes to building codes can actually make a big impact. Simple requirements force everyday decisions to higher standards, and in the case of these energy-efficient trends, the higher standard means a lighter carbon footprint across the board. In the past, some of these building decisions might have been a nice idea, but when push came to shove or budgets got tighter, the energy-efficient measures might have been the first thing to go. However, when they’re a requirement, there’s simply no room to question it. With each new code change to be more energy efficient, you start to see a better carbon impact across the board. 

Changes On All Levels

As we’re based in Colorado, we pay close attention to the local municipalities and those in our immediate vicinity. We’ve seen municipalities including Denver, Boulder, Golden, Fort Collins, and others increasing their energy-efficient codes across the board. However, on a national level, we’re seeing significant increases in code requirements as well, including New York City and Boston. And, Passive House Design plays a larger role in these municipalities because it easily meets, and often exceeds, the new code requirements. 

However, these changes are not just happening here in North America. In fact, the global push for energy efficiency has been largely attributed to the Paris Agreement, established in 2015. The agreement is focused on addressing climate change with goals to reduce greenhouse emissions, support developing countries’ efforts, and collaborate together. While the United States was part of this unifying group originally, the 2020 administration pulled the US out of the Agreement. US involvement or not, the Paris Agreement has had a major influence on the carbon impact on the globe and we’ve seen countries make significant changes in just a few short years. Others have followed suit, realizing that energy efficiency has major benefits from so many angles. This global initiative has put climate concerns and energy efficiency as a top priority for many governments, and as a result, we’re seeing the effects even in our local municipalities! 

How do we enact even greater change? 

While there’s much to celebrate, there’s still a huge opportunity to do better by our planet. Here are just a few ways to continue the journey toward better energy efficiency and lower carbon impact to the earth: 

  1. Vote with your dollars: Put your money where your mouth is and invest in energy-efficient systems and products when you build your next project. It’s worth it! 
  2. Vote with your vote: Think about sustainability when you’re casting your ballots and work to elect officials who care about sustainability initiatives. 
  3. Share the wins: Talk with friends and family about the progress communities are making toward being energy efficient, and even any wins you’ve experienced on your own end. Don’t preach, but be willing to share. 
  4. Research: The more educated you are on energy efficiency, the better decisions you will make. Don’t rely on others to simply spoon feed you the highlights. Be a smart consumer and resident, and learn how you can support energy-efficiency initiatives that might be happening in your own backyard. 

We get excited over here about building codes, especially when they support energy efficiency. We also love seeing the ripple effect of what these codes do for the local carbon impact. As an integral supplier of energy-efficient products, we know how important these building codes can be toward a bigger, more energy-efficient future! 

Tour Local Passive House Designs

Green geeks united this summer at Emu Building Science’s 2022 Passive House Open Days! What a great event, and amazing that this event will be coming back again later this fall! 

Emu started creating a Passive Haus Days Tour to celebrate local Passive Home designs and construction. Similar to other home tours, attendees can sign up and tour the homes on the list. Emu’s tour is specifically focused around Passive House Construction and seeing the work in action. It helps give people a vision for what could be a reality in their homes and helps make passive construction strategies more mainstream and accessible to homeowners. 

AE Building Systems was excited about the Summer 2022 tour by Emu, specifically because our team was part of multiple homes on the tour, including the Fisher Residence and the Kirsch-Stroupe Residence.

Fisher Residence (Milhaus)

This Fort Collins home is the modern farmhouse you always dreamed of. AE Building Systems was proud to support this resident, who was also the architect and builder, with Smartwin, Alpen windows and doors, and SIGA weather/air barriers. 

Read more about this project and the amazing design! 

Kirsch-Stroupe Residence

Sustainably-minded homeowners drove the desire for Passive House practices, and the result is simply stunning. AE Building Systems was honored to contribute to this project with SIGA exterior air barrier (Majvest, Wigluv, Fentrim 430), SIGA IS 20 for window details, and SIGA Majrex/Rissan for the interior air barrier materials. 

Read our full profile on this resident in Tabernash.

Donath Lake House(s)

These Fort Collins spec homes were constructed by Black Timber Builders, and the Donath Lake Community is the only single-family community of Passive House Certified Homes in the nation! We know the folks at Black Timber Builders well, and they have a reputation for excellence. Walking through these lake houses was a real treat! While these homes were largely pre-sold, they were spec builds, and the possibilities with Black Timber moving forward are simply endless! 

Ogden St. Complex

This multi-family certified passive house in Denver is an innovative look at sustainable design for multi-family construction. It has a sleek, modern design, infusing new life to the block, and is Colorado’s first multi-family passive house! This appeals to a different market of homeowners who are looking for multi-family construction but also want sustainability. The project also achieved a 0.28 ACH50 with a firewall, which many professionals didn’t think was possible. The project is literally paving the way for future construction performance in Denver! 

Interested in checking out another event like this? Emu’s upcoming Passive Haus Open Days is coming up on November 11-13! Follow them on Facebook to find the registration details when they’re released. 

Project Spotlight – Smithworks project @ Crested Butte

You CAN Have it All: Form & Function Unite in Crested Butte – Smithworks Restorative Lake House

You know what gets us really excited? It makes our day to see sustainable products in action for real families. That’s why we’re thrilled to share the Smithworks project with you today! 

The Smithworks Team

Smithworks has a reputation for excellence that dates back to the 1990s. Smithworks is led by Don and Elizabeth Smith, who are both local residents of Crested Butte. They love being part of crafting the local community with excellence in design and craftsmanship. This passion for design and innovation has led the duo on a journey to build stunning homes in the Crested Butte area. Environmentally-friendly products and building methods are the standard for them, and they have a huge focus on building homes that harmonize with the scenic mountain backdrops. 

Smithworks – Crested Butte Project (Restorative Lake House)

While each home has its own unique look and feel, Smithworks puts a few common features into each home that center around sustainability. Below are a few of the project features for this remodel project:  

  • Net Zero: This home is a climate-resilient, all-electric home that boasts a net zero carbon footprint. Between energy-efficient construction practices and other features like solar panels, this house remodel had a major focus on sustainability. 
  • Wall Assembly: Great attention was taken to the fenestration details and air sealing details in the wall assembly to ensure this house is as solid and airtight as possible. They built extremely thick walls with the existing 2X4 and then a TJI “quilt” with cellulose insulation throughout the entire assembly. 
  • Air Infiltration Mitigation: Because this house was a retrofit, the construction team resheathed the primary framing with ZIP and then added TJIs to the exterior. They then filled both cavities with cellulose. 
  • Blower Door: The team achieved a blower door test of 0.26 ACH50. They joke (and it’s probably true) that this house is the tightest house in the Gunnison Valley. 
  • Smart Ventilation: Interior air quality was a major priority on this project. The CERV2 was utilized on this project, providing the highest level of smart ventilation for the home. The CERV2 sensors automatically measure and maintain excellent air quality in your home. It also helps with energy recovery in the home, which is going to be an ideal bonus for a home in this mountain valley. 
  • High-Performance Openings: Smithworks employed the Advantage Smartwin© windows and doors for ultimate energy efficiency and performance. Smartwin© products are one of the best performing products currently in the world. The temperature swings in this mountain town are no match for these windows and doors, and the residents will feel how stable the interior air temperature stays as a result of these high-performance windows and doors. 
  • Unparalleled Design: This house functions well from an energy-efficiency standpoint, but the house is also a work of art! It fits into the landscape so well, accentuating beautiful vistas, embracing the mountain lifestyle and aesthetic, and has a ton of little moments throughout where the detail is simple, yet sophisticated. Smithworks excels in providing that high level of design, but with a house that is sustainable, solid, and ready to last for generations. 

Working Together

“We received good customer service from AE Building Systems that you just don’t get with other companies.” – Don Smith

Smithworks has a great relationship with the AE Building Systems team. We’re proud to support local Colorado contractors with not just sustainable building products, but with customer support as well. We pride ourselves in going above and beyond to make the products right, and give as much product knowledge as possible. We’re proud to support great products like the CERV2 and Smartwin© windows for residential projects. We’d be happy to help anyone considering these kinds of projects for your next project. We LOVE answering questions to help you find the right solution for you!

Projects like these are good reminders and proof that you can build not only energy-efficient homes, but also ones where there is comfort, health, and high performance too. On top of that, this type of design can be extremely beautiful while being so functional and sustainable. You CAN have it all, and the Smithworks Crested Butte residence here is a prime example! 
Get more on this project from the Smithworks’ project overview!

Thinking About Air Quality Gets Front & Center

We bet you have thought about air quality a few more times since 2020 than you ever did before! The recent pandemic has made so many of us aware of the particles in the air we breathe that can make us sick. Those of us in Passive Home design have always been aware of air quality and how we can make the air we breathe inside of our spaces as healthy as possible. It’s always been front and center in our design approach. That’s why we focus so much on Energy Recovery Ventilators in our conversations with customers and partners. 

Energy Recovery Ventilators (ERV) are a vital piece of equipment for passive or high-performance homes. Most existing homes are super leaky and get plenty of “fresh” air through the holes and cracks in the building envelope. Newer homes are getting more and more airtight and need more fresh air. ERVs are designed to provide ventilation that removes stale air and sometimes humidity, while delivering fresh air into the home. That “stale” air contains CO2, humidity, and toxins. We breathe, creating humidity and CO2, and cook, creating humidity and toxins. That new couch with the new couch smell – well – that smell is usually not good for you. The smell is generally toxins off-gassing from the materials the couch is made of. 

At the very core, ERVs have blowers and a heat exchanger. Their primary objective is to improve indoor air quality by bringing in fresh air. In the winter months, ERVs help recover warm air that may have otherwise been lost, especially in leaky, older homes that get plenty of fresh air through the holes and cracks in the building envelope. ERV systems capture some of the warmth from the exhaust or stale air stream and transfers that warmth back into the fresh air stream it’s pulling from the exterior. Likewise, in the summer months, ERVs help keep the heat out and the cool in by reversing the process. They put the “warmth” coming in via the fresh air stream into the exhaust air stream. In doing so, ERVs improve the HVAC system efficiency of a home as a primary benefit! 

What’s the Difference Between an ERV and an HRV?

When you start looking into ventilators, you will see the acronym for Heat Recovery Ventilator (HRV) pop up. At first glance, it may feel like ERVs and HRVs are the same. The primary difference is ERVs manage or transfer humidity where HRVs dump the humidity, especially during the colder months when it’s pretty dry and we benefit from the humidity. The entire discussion around whether you should have an HRV or an ERV is changing. The variables historically included the size of the home, average humidity, and whether it is a heating or a cooling climate which is defined by heating/cooling degree days. It is our understanding that ERVs are the current direction in general, especially with high-performance, airtight homes.   


With ERV systems, the ducting is a vital piece of the process. While some units do a lot of sophisticated work, the design of the ducting is crucial for success with all types of ERV and HRV systems. 

Here are a few key guiding principles for duct design:

  • If possible, keep ducting as short, fat, and straight as possible to minimize static pressure and air turbulence. Static pressure makes it harder for the blowers to do their job and the system wears out sooner as a result. Go deeper into the math on duct design! 
  • Set up dedicated ducts for an ERV in new construction. In retrofits, existing ducts can be leveraged as well. There are some important considerations on where to tap into those ducts.
  • Insulate Fresh and Stale air ducts as much as possible. R-8 or better is the general recommendation. These are the ducts that go to the outside wall and bring in the fresh air and exhaust the stale air. Also, these ducts shouldn’t terminate right next to each other on the wall. They should be at least 10 feet apart.
  • Return ducts are generally for polluted and humid areas – kitchens, baths, or even laundry spaces.
  • Supply ducts generally go to the living areas and bedrooms.  
  • Consider a sound dampening option with insulated flex or a silencer, especially in high-performance homes. Blowers and airflow generate some sound; generally, high-performance homes are super quiet. Our feedback from clients has been the “ERV is making noise” and silencing ducts help reduce the noise.

ERVs We Love

Our team is a big fan of Build Equinox’s CERV 2, which uses a high-efficiency heat pump to exchange energy(heat) between incoming supply and outgoing exhaust air. The CERV 2 measures and manages indoor air pollutants, CO2, and humidity. It brings in fresh air only when you actually need it. It also has an efficient inverter drive heat pump, which performs the heat exchange. The heat pump assists the primary HVAC system with heating and cooling. Built with the user experience in mind, their color touchscreen controller is easy to read and simple to use, and you can even manage the system remotely! 

Your ventilation system is likely the most important system in a Passivehaus design. We care about air tightness for a home, and we care about good air quality as well, especially for the Passivehaus. As a result, you can’t afford to just phone in this part of the process. That’s why we encourage our customers to talk to their HVAC expert, like BrightSense, to help you create the optimal design with product selection and ducting design. Please note that your HVAC expert should also be able to help you confirm your flow rates with a duct blaster. 

While we aren’t HVAC design experts ourselves, the AE Building Systems team knows a lot about the CERV2 system and many of the nuances you should have on your radar. We’re always here to help point you in the right direction and think through the various angles on your own project! 

Passive Window Design for Optimal Performance

You thought windows were really simple and easy, right? Well, think again, my friends! When you pair high-efficiency windows with high altitude and differing sun exposures, you soon discover there are many possible ways you can not only optimize your window performance, but also set yourself up for failure!

Thin Air

Altitude is no joke, and you can literally feel it when you come from lower lands or sea level to visit a state like Colorado. The locals will all tell you to drink lots of water and if you try to go for a light jog, you may feel like you actually just attempted a marathon instead. The altitude has a real and major effect on the body. The same is true with windows. 

Why Does Altitude Matter?

High-performance windows today are equipped with triple and even quad glazing to form insulated glazing units (IGUs). IGUs have an airtight seal around the perimeter and trap the gas between the panes. Typically, gasses like argon and krypton are used. 

IGU’s perform best when they are assembled at the altitude where the final installation is. When IGUs are transported from a factory at sea level to a place with high elevation like we have in Colorado, it’s a recipe for disaster. When the altitude delta exceeds 1,600 feet, it becomes problematic because the barometric pressure varies enough to create complications. For example, when going up to 5,000 feet in elevation, the atmospheric pressure is much lower than at sea level. Think about what happens to a bag of potato chips. Most mainstream companies don’t gas fill and insert a capillary tube so the glass doesn’t break or even blow up in transit. Alpen HPP uses breather tubes and balloons to regulate barometric pressure of the gas used in their windows. There are other ways to manage barometric pressure to include pressure release valves as well as pre-pressurizing in the factory to the average barometric pressure for the installation location.

Hello, Mr. Sun!

If you’ve ever been in Colorado on a sunny day in the winter when it’s around 50 degrees, you may have experienced some hot flashes in your car where you scurry to get your air conditioning going. Wait a second! In the winter?? Yes, my friends, the sun is that intense here at higher altitudes and especially when it’s streaming through the glass of our cars. 

Now, let’s apply that to our homes. Solar heat gain coefficient (SHGC) is the fraction of solar radiation admitted through a skylight, door, or window, whether directly and/or absorbed. That radiation manifests as heat within the home. 

A lower SHGC window reduces solar heat and provides greater “shading” essentially. Glazing products with low SHGC ratings are more effective at reducing cooling loads during the summer by blocking some of the heat gain from sun radiation. Even up in the mountains, low SHGC glass is often used on the west elevation of a home to reduce summer overheating.  A glazing product with a high SHGC allows more solar heat gain which is great in colder months. Your home’s climate, orientation, and shading will drive the optimal SHGC for each window, often depending on the elevation or which side of the building the windows and doors are installed.

Please do not mistake SHGC with UV; these are different things. That said, one of the benefits of Alpen’s High Performance glass is it protects against up to 99.5% of UV rays. UV rays are damaging to virtually everything, including our skin. Related to windows, UV rays can damage nearly every finish in our homes and UV protection keeps interior finishes, wood, and furniture from getting damaged and discolored.  

Where Higher SHGC is Helpful:

In colder, heating-dominated northern climates, both SHGC and a window’s U-factor should be taken into account for energy efficiency. In heating climates where heating is a bigger concern than air conditioning, a higher SHGC in the range of 0.30 to 0.60 can be helpful especially on our south windows. During the winter months, the sun is lower in the south sky and the solar heat that is gained from the sun helps warm our homes.

Where Lower SHGC is Ideal:

In the Southern and Central states, where the climate can get extremely warm and air conditioning is used extensively throughout the majority of the year, a lower SHGC is ideal and desired. This equates to less heat gained from our windows. 

With most of our projects, we tune the windows by the elevation (North, East, South, West).  There have been rare occasions that windows even on the same elevation might have different SHGCs.  A north-facing window is going to behave differently than an east, south, or west-facing window simply based on the position of the sun throughout the day and the seasons. If you “tune” each window to be a specific value, make sure that each window is tagged properly and that the contractor pays attention to where each window needs to be installed, which is critical if you have a lot of the same sized windows. 

Of course, specifying this level of detail on each window is as much a science as it is an art. Note that SHGC levels generally run parallel with the visible transmittance of natural light.  While not noticeable by most people, there are slight hue differences with different SHGC glass. We know that every home’s windows are not just built to function well, but also to enhance a view and afford us natural light. In the mountains, we have some pretty spectacular views! Often, it’s a real-world balance to get the best performance while considering natural light in the home. [NOTE: it’s recommended to consult with an energy modeler in the process.]

So, those simple windows don’t seem so simple anymore, eh? There’s actually a whole lot more going on to make sure they will work optimally for your home. When you put this level of attention into your window design, you really can achieve some amazing results in performance, and as fans of sustainable, efficient homes, we love that! Love the idea of high-performing windows in your home too? Not sure where to start? Let us help you break down some of the basics and how they might apply to your home’s strategy.

Anatomy of a Window: Basics for High-Performance Windows

It’s time to get up close and personal with windows! We usually just focus on the scene we can see through the window, but what looks so simple can actually be very complex. 

There are three main sections to the overall anatomy of a window: frames, spacers, and glass. While we often focus on the shiny, pristine look of the clear glass, we understand that ALL parts of the window are vital for overall performance and ultimately providing better thermal performance for any house. 

Window Frames:

We often focus on the glass performance, but the frames are quite literally what holds so much integrity for the window performance. Not only do they offer structural support, but they are huge opportunities to preserve energy efficiency. Most companies don’t insulate the frames, but high-performance manufacturers will use various types of insulation. These can vary from EPS, wood fiber, and Polyurethane. 

At AE Building Systems, we’re big fans of:

  • Tyrol, Tyrol PH+ Windows, with either EPS or Graphite for insulating support
  • Zenith Windows (with Polyurethane), which offers higher insulation value per inch 
  • Smartwin by Advantage offers wood fiber and XPS insulation options
  • Advantage Mira, not insulated much, as it’s made of mainly wood (R-1 per inch)

Window Spacers:

Spacers are a vital part of every window’s anatomy and help provide structural integrity of the glazing unit while promoting a thermal and moisture seal. Spacers are usually made with either aluminum, steel, stainless steel, warm-edge, or composite. When a high-quality spacer is used along with gas filling and low-e-coated glass, the overall energy-efficiency of the window is improved.

Window Glass: 

Simplicity is the ultimate sophistication. – Leonardo Da Vinci

While it may look like just a simple, clear pane you look through, what’s going on is actually pretty sophisticated. There are so many factors to think of when it comes to insulated glass. Insulated glass is insulated with gas, such as Argon or Krypton, and the cost for these gasses varies based on the current market price. Elevation also plays a factor in expansion levels for gas, and with our team based in Colorado, we are highly aware of ensuring that windows are manufactured appropriately based on the elevation they will be used at. To quote our friend Leonardo, insulated glass is highly sophisticated, but can appear so simple to the untrained eye! 

Below are some of the most common options for residential window glass:

Double-Pane Windows:

A double-pane window has two panes of glass set into each window frame. The two glass panes have a small space between them, which creates an air pocket to provide a small level of insulation. If you’ve ever felt a single-pane window on an antique window or in an older home, you know that there’s minimal insulation and the glass is going to be very cold or very hot depending on the season. However, many homes historically have leaned toward double-pane windows, which will still be warm or cool to the touch, but not as drastic. While more cost-effective upfront, double-pane windows can cost you more in the long run as they aren’t nearly as efficient for insulation and energy transfer as other options available today. 

Euro Triple-Pane Windows: 

European windows are well known for their high energy efficiency. Their design allows less heat to pass through from your house when it is cold outside. Triple-pane windows are better thermally because of the added pocket depth for argon gas between the window panes. They ultimately have the potential to reduce energy costs, reduce noise, increase comfort, and even reduce the size and wear on HVAC equipment.  

Quad-Pane Windows: 

Quadruple Pane Windows, or Quad Glazed Windows, include four high-performance layers of glass with three gas-filled sealed air spaces in between. With an added pane of glass, they are a solid solution in terms of insulation, heat transfer, and other aspects as well. Think of all the benefits of double-pane and triple-pane windows but with an additional pane. Of course, any time you add material, you add weight, cost, and complexity. For many residential situations, triple-pane ends up being the nice winner for an all-around solution that supports energy-efficiency, more common construction practices, and construction budgets. 

Thin Glass vs. Thin Film Windows

Thin Glass and Thin Film are like cousins, who are similar, but just not completely the same product. They also are very similar to triple-pane windows in a high-level concept. Thin Film has been Alpen’s go-to for many, many years, and will still be available for many of their lines, such as Zenith and Tyrol. However, Alpen recently released Thin Glass, which acts like a triple-pane window at a double-pane’s weight. Of course, it’s much more complex than that. You can read up on more of the details to these innovative options here, where we break down how they’re similar and how they differ.  

Innie vs. Outie Window Construction

In construction, this great debate has been going on for some years and it can be confusing to know what the right solution is for your project. Each style has been used in various ways over the years, but if you’re like us and are concerned about thermal performance and energy savings, you will want to read our detailed blog

Windows are one of the most important features in a home, especially if you love where you live (like we do here in Colorado)! You want to let the local scenery and the sunshine in, but you also don’t want to sacrifice thermal efficiency. That’s why it’s so important to get the window purchase right when you’re building or upgrading a home. Some window options will be better for you than others and that’s where our team is here to help! Let us help you find the best high-performance window to meet your needs. We’re here to answer any and all questions; email 

Debunking the Myth that Insulation is ALWAYS Better Than Glazing for Thermal Performance

The immediate place our minds go when it comes to improving the performance of a wall is to insulate. That seems to be the easiest and simplest approach to improving performance and energy efficiency. But, what if we told you the glazing is where you really get the bigger bang for your buck? Would you be surprised? 

Most people are, and note we are assuming more standard residential construction and assumptions include 2X framing and batt insulation. Construction with steel studs, concrete, continuous insulation, thermal bridging, etc. alter the results in different ways.

A window is essentially a thermal “hole in the dike,” and insulation in walls above certain R-Values becomes less and less helpful when looking at the overall performance of the wall – window included.  

Okay, so we can all get behind the idea that insulation in the walls is a good thing, and surely it’s effective for energy-efficiency. Is it not a pretty bold statement to say that glazing is MORE effective? 

Hang on with us…

Gazing at Glazing Options:

We have single pane glass, which keeps out the elements and is worthless in terms of thermal performance. We don’t see these in modern construction, especially in sustainable, energy-efficient projects. 

Many homes have dual-pane insulating glass, which is two glass panes with a low-e coating, separated by a small sealed air space. When inserted with a gas like argon, it increases its insulation. You can see maximum performance ratings up to about R-4 with most options landing around R-3.5. 

Other windows feature triple-pane insulated glass, which increases that dual-pane concept by an extra pane and an extra insulated chamber. Triple-pane (the glass IGU specifically) can be up to 50 percent heavier, difficult to handle, and require stronger supports. However, you can get insulating properties up to R-10 center of glass (COG). 

On standard walls, we might be lucky to see an R-20 effective R-Value, but in many commercial curtain wall systems, “high performance” can often be categorized as an R-4 wall. A simple look at the numbers above shows the very high-level understanding that if you go the route of energy-efficient windows, you can achieve similar, if not better, performance than a curtain-wall system. In residential wall assemblies like 2×6 construction, effective R-Values run R-10 to R-14 as there is thermal bridging in the 2×6.  This is a whole different topic and we’re going to stick to a basic wall R-value.

Okay, high-performance windows are great, but couldn’t you just beef up the insulation to compensate for lesser-performing windows? 

Let’s do some math:

Let’s suppose a facade is 75% wall and 25% glazed. The wall part is R-20, and the window is at R-3. In this situation, the thermal performance of the overall wall with windows is roughly R-8.3. 

Now, if you double the performance of the wall portion to R-40 (keeping the window at R-3), the R-value for the overall wall (windows included) is slightly better at just R-9.8, so not much difference compared to where we started.  You’d think that 100% increase in wall R-value would yield more than an 18% improvement in the overall wall – windows included. 

BUT, what if we changed out the windows and doubled their performance to be R-6 (and kept the wall portion at R-20)? If you do that, and re-run the calculations, you actually get an overall wall performance of R-12.6! At 53%, that’s a pretty high percentage increase. 

Oh… by the way… going to R-40 walls and R-6 windows takes the overall wall R-value to R-16.5, and R-40 walls and R-9 windows takes the overall wall to R-21.5. However, R-60 walls and R-3 glass is around R-10.5 Glazing is truly the weak link in our wall assemblies.   

Watch this video by Todd going into more detail on frame types, triple vs. quad panes, spacer options, and ​​gas types.

While it feels counterintuitive, going for the high-performing windows actually moves the needle further than beefing up insulation in the wall itself. Curious about what kind of high-performance windows are right for your project? Talk to our team about maximizing your overall R-values. We LOVE sharing our knowledge to help you make the right decision for your next project! 

This project has R-7 to R-9 fenestration products and approximately R-40 walls.


Collins Residence Part II

Last month, we took you on a behind-the-scenes peek at the Collins-Ruddy project. This tri-level home was a retrofit from a 1970’s where energy-efficiency was clearly not in the original blueprint of the home. Todd and his family began a journey to improve the energy loss in their home, and incorporate Passive Haus techniques wherever possible. 

We use the word “journey” because that’s truly what it has been. They started this project in 2012 and are still to this day finding ways to improve. If you’re just catching this journey here in this article, take a look back at the first half of the journey we shared last month.

Today, we want to share more details about this project:

Biggest Lessons Learned:

  • Solar: Todd wishes he had installed more solar panels than he needed originally to account for these future needs. While they maxed out the federal incentive, as it stands, they will need to upgrade their solar system to get them to Net Zero with vehicles, equipment they have, and what they plan to have in the next several years. 
  • Entry Doors & Floors: The doors were installed prior to considering a wood floor upgrade. Because the doors were installed lower, standard wood floors were no longer possible or the door would not be able to open. Instead, Todd installed engineered flooring which is not as thick. 
  • Attic Insulation: Todd says if he had to do it over, he would have started from scratch.  Clear out the old insulation, then start with a thick layer of foam at the attic perimeter and wall connections, foam the j-boxes and any other penetrations… and then finish with a huge layer of blown cellulose. It’s more costly to do it this way, but it’s also more effective for a couple of reasons:  higher r-value at the perimeter and is more airtight. 
  • Win the Lottery: While a pipe dream, Todd jokes that he would have won the lottery before approaching this project. It sure would have made the process easier! The process can get pricey with the more costly upgrades like windows and solar panels.  

What’s Still to Come?

Remember we mentioned that this is a journey? That said, between budgets, finding quality labor/contractors, sourcing supplies, and just mere time, retrofitting a house to be more energy-efficient usually doesn’t happen overnight. 

Here are a few projects they plan to tackle in the future: 

  • Remove the siding, add an air barrier and then 3” of mineral wool continuous insulation, and finish the exterior with new siding.
  • We might consider re-insulating our walls at some point as there is only poorly installed batt insulation. The re-insulation process entails cutting holes and filling the walls with cellulose.  
  • Purchase a new heat-pump water heater.
  • Replace the furnace with a whole house heat pump when it approaches end of life.
  • Increase solar panels to get to Net Zero.  
  • Go all electric and cut the gas. 
  • Go all electric for our cars as well … and utilize our solar energy production to charge them. While we have started this process with a RAV4 prime – plug-in hybrid, future vehicles will eventually be all electric.  

Here’s the new video >>

Why Do All This? 

Sometimes they get quizzical looks from neighbors and friends as they share about their journey and projects. Why would you invest so much effort into improving so many things that you will never see? Sure, there are fun things like a kitchen remodel that you see and experience day in and day out that make a difference.  Initially, it was about their children sleeping through the night and it’s pretty easy to forget the fact that you don’t have to cover your feet on freezing floors or the fact that you can live without space heaters in the dead of winter.  Finally, Todd has the peace of mind that energy price increases won’t be that impactful on his bill. 

Their family knows the power of energy-efficiency and how it can not only save a lot of money in the long run, but it reduces the need to rely on creating more heating or cooling. They’re proud supporters of sustainability efforts that reduce their carbon footprint and energy load on the earth. If we can build a better space that asks less from our energy resources on earth, why shouldn’t we? That’s their approach. 

At AE Building Systems, we want you to know that you don’t have to be breaking ground on a brand new custom build to employ energy-efficiency into your home. Odds are, most of us reading this have purchased a home where we inherited energy-efficiency issues, thermal bridging, and other concerns in a pre-owned home. Most of us will be where Todd and his family were: faced with retrofitting and solving problems as best we can with the house we’re in. 

We want you to know you CAN make a difference in your own home. Small steps can make a BIG difference when it comes to energy-efficiency, energy savings, cost savings, and sustainability efforts. You can be part of it, and we want to help you on your own journey. 

Got questions for Todd or want to know where to start? Feel free to reach out! 

Todd Collins 720.287.4290

Collins-Ruddy Residence Part I

Here’s a look at how the Collins-Ruddy family worked to retrofit their home…

We like to practice what we preach here at AE Building Systems, which is why we’re excited to share about a project for our very own Todd Collins! (If you haven’t met Todd yet, below is a quick intro.) The Collins-Ruddy Residence is probably much like your own home: it wasn’t built from scratch with Passive Haus/energy-efficiency in mind. So many homeowners buy a home that meets other needs, but often doesn’t tick the box of efficiency. And so, we enter a retrofit situation! 

Setting the Stage

The Collins-Ruddy Residence is a 1971 tri-level home with a basement (four levels in total) with 2×4 construction, and fiberglass batt insulation. The home has had some window replacements, but they are still lower performance windows than the ideal situation. The house has forced air heat with a gas furnace, and a gas hot water heater as well. The house also came with a programmable thermostat, reasonably new range with a convection oven, electric resistance cooktop, and an old Montgomery Ward Fridge.  

The Collins-Ruddy family keeps the thermostat roughly at 68 degrees F in evenings and mornings, and 60 degrees F at night and when not occupied. Of course, remote working and virtual school have changed the game for their recent years’ occupancy. 

The Problem

Todd and his family care deeply about Passive Haus techniques and energy efficiency, so any home they would have purchased would have needed some adjustments in their eyes. However, this tri-level posed a few other obvious problems for them. The young kids’ bedrooms were COLD at night, resulting in poor sleep for them (and the parents)! They also experienced thermal bridging in most zones of the home, which were accentuated in extreme hot and extreme cold seasons!

The Investigation

Todd decided to get an energy audit for their home to evaluate how and what to focus his attention on to improve energy efficiency. 

The Solution: Phase I

As a result of the audit, Todd did a few simple things to help within their current framework. Below is a rough timeline of their journey so far:


  • Wrapped the water heater – Cost $40 for “insulation blanket” 
  • Power strips at TVs and Computers – Cost $50 to reduce phantom loads 
  • Gas Fireplace – Taped it off with an air barrier 


  • New Washer/Dryer – Cost $1400 – high-efficiency units
  • New Fridge Cost $1100
  • New Garage doors – R-10 and reasonably airtight
  • New Ceiling fans – To reduce A/C usage – DC/ECM motors and CFL/LED lights $2400
  • Insulation/Air Sealing Contractor $4,100 
    • Insulated – skylight walls in attic – blanket insulation  
    • Insulated – knee-walls between attic and conditioned space – similar to skylight walls
    • Air-seal attic junction boxes – ceiling fans (6) and electrical boxes – 3 new, 3 replaced 
    • Air-seal attic along exterior and interior walls – foamed attic wall junctions and gabled end where the walls meet the attic  
    • Attic hatch dam to hold insulation back  
    • Insulated attic hatch with 10” of recycled XPS and Poly-Iso 
    • Attic Insulation – increased insulation to R-65 (increase of R-25+) in two attic spaces 
    • Air-seal bottom plate – foam insulation in bottom plate rim from the interior 
    • Drill and Fill above garage/below bedrooms
    • New bath fan with DC/ECM blower motor 


  • Installed Solar Panels $15,000 installed  
    • 3.9 Kw System – covers all electrical and then some


  • Windows/Doors $27,000 installed  
    • Replaced all windows and doors – R-7
    • Added two new South facing windows  
    • Installed new entry and French doors – R6 (Euro-style with multipoint locking for airtight and sound dampening results)
    • Installed new door from garage to interior of house (insulated fiberglass r4)


  • Basement – our office and workout space was cold due to thermal bridging  
    • Taped the bottom plate on the interior to reduce air infiltration  
    • Insulated basement walls with 3” Rockwood Continuous Insulation 


  • Kitchen remodel with energy-efficient appliances 
    • Induction cooktop 
    • Convection oven 
    • Fridge – second version 7 years later  
    • Dishwasher 
    • Nest Thermostat 


  • Replaced Lighting – CFLs swapped for LEDs  
  • Retaped furnace ducts where accessible  

The journey to better energy efficiency doesn’t stop, but as you can see this is a journey. Retrofitting a house doesn’t happen all in a blink of an eye, and this project is a case in point of how you can focus on small, low-hanging fruit, as well as bigger projects as your budget and time allow. 

Join us next month to see how all of these changes have worked out for Todd’s family, as well as other issues they still plan to address in order to improve the house even more!

Got questions for Todd? Feel free to reach out! 

Todd Collins 720.287.4290

Evergreen Home Marries Form with Function: Summit View Residence

At AE Building Systems, we love seeing products in action, especially when they are at work in smart ways. That’s why we love seeing the progress at the Summit View  project, nestled right in the heart of the Rockies. This home reflects the beauty of design, and the high-quality foundation of energy efficiency at the same time. When you build with quality products, it will not just look good, but operate well for the occupants for years to come!

Rangeline Homes

The Summit View project is headed up by Rangeline Homes, a general contractor based in Evergreen, Colorado. Rangeline has over a decade of experience with high-quality, sustainable residential construction. Their team is led by Luke Mann and Todd Switzer, both of whom are hands-on and big on communication throughout the entire project.

The Summit View home was designed to ultimately maximize this lot’s stunning mountain and lake views. As a result, special attention was taken to the positioning of the house on the lot, as well as windows and entryways. Mount Evans is the show-stopper in the view, and the house is not far from Evergreen Lake, downtown Evergreen, and Three Sisters Park. 

Design and aesthetic considerations were the primary focus on this project, as the views and setting are simply extraordinary. However, they also didn’t want to sacrifice performance just for the sake of good looks. They were looking for products that would provide the quality and excellence in performance to work well at this high elevation with colder winter temperatures and harsher weather. 

Smart Design with Quality Products

AE Building Systems was proud to support this project with a few core products including the Alpen Fiberglass Zenith 625 window system, the Advantage entryway door, and ProVia swing doors. The Alpen window products are a great solution to provide a stunning look, with high-performance thermal efficiency.

The Rangeline team also paid close attention to the wall assembly to reduce thermal loss. The exterior is cladded in a boral/stone material with Zip R6 sheathing. Then, they tied it all together with a closed cell spray foam to fill up the 4.5” deep walls on all exterior walls. 

Luke and his team were intentional on the blower door on the project as well: 

  • Pre seal blower door results (no masking) 2.51 ACH 50 (3381 CFM)
  • Pre seal blower door results (fully masked) 2.23 ACH 50 (3002 CFM)
  • Post Seal after AeroBarrier Completed .78 ACH 50 (1045 CFM)

Unrelated to performance but quite unique and frankly dramatic, Luke and his team figured out how to light up the translucent countertop.  The images below show the effect. 

The Summit View home is simply stunning and the great craftsmanship shines through. Our team was honored to be part of the process and support Rangeline Homes in the construction process. We love seeing examples where form AND sustainable function come together for a gorgeous build that operates efficiently as well. 

Project Specs: 

Location: Evergreen, CO
Architect: Mosaic Architects
General Contractor: Rangeline Homes, IG: @rangelinehomes

Don’t Get Exhausted by Kitchen Ventilation Strategies

An Overview of the Options & Approaches for Kitchen Ventilation

Your kitchen must be so exhausted! A lot of work happens in the kitchen, so not only are your appliances doing a lot of work, but the air needs to be exhausted out to keep the air quality in check. There are typically two main elements involved in venting a kitchen space: capturing and removing pollutants and exhausting them outside. And whether you’re dealing with a Passive Haus kitchen or just wanting better air quality, ventilation strategies are an important thing to consider. 

The Great Debate: Vent Out or Recirculate?

Wall-Mounted Hoods

A common method for ventilation is a wall-mounted hood, which provides a steady, effective fume capture, especially compared to island extractor hoods. Within the same capture capacity, wall-mounted hoods can have a 40% lower flow rate compared to island extractor hoods! Mounting standards suggest that they be placed 50-60 cm, or about two feet, from the cooktop. When installed higher, which is very common, they lose effectiveness as air can escape out into the rest of the room. 


The jury seems to still be out when it comes to venting vs. recirculating. That said, many experts argue adamantly that venting to the exterior is an absolute must. A PHI report notes that “no moisture loads are removed with recirculation operation,” so other ventilation is required, and “in order to ensure proper functioning of the recirculation air system and limit the pressure losses, the air filter must be cleaned and/or replaced at regular intervals.” 

Is Exterior Venting 100% Effective?

From an air quality perspective, exterior venting appears to be a no-brainer! However, in Passive House buildings, the use of a kitchen exhaust air system may actually increase the demands on the heating system. It creates another penetration within the building envelope, requiring even more focused attention for airtight construction. 

As a result, when it comes to Passive House design, some folks lean toward recirculation hood systems. 

Small dwelling spaces, like apartments, also become difficult for exterior ventilation, and lean toward recirculation instead. 

So, what is the best approach? 

First off, keep in mind that kitchen ventilation is a hotly debated topic and you’ll find experts that have different approaches. Not everyone is approaching things evenly. Some care more about air quality than energy-efficiency and vice versa. 

From our perspective, as we weigh the Passive Haus approach, plus healthy air quality, here’s how we would approach this puzzle for a brand new Passive Haus project:

  • Use an induction range, rather than an electric or gas stove. Induction cooking produces fewer VOC’s just by nature. Plus, it’s more energy-efficient! 
  • Ensure the duct to the kitchen is sufficiently large to pull at least 300 CFM from the kitchen. 
  • Recirculate the kitchen ventilation system, either with a downdraft or a hood, using a carbon filter. Pair this with the CERV2.
  • Set up the CERV2 zone damper and a wireless transmitter on the vent to exhaust the kitchen. The wireless transmitter communicates with the CERV2 unit to go into “boost mode” or max the volume within a set time period. Ideally, set up the CERV2 to pull all return air from just the kitchen space, rather than both bathroom and kitchen, by using the zone damper and cutting off the returns from the bathrooms. 

Why CERV2?

The CERV2 for kitchen ventilation is effective as it can reduce and minimize penetrations in the structure’s building envelope, balances filtered make-up air, supports energy recovery, and reduces pollutant levels in a home. The CERV2 has so many amazing benefits, especially when you’re looking for energy-efficient, or Passive Haus tactics. Take a look at a good overview of how you can improve indoor air quality with the CERV2. 

As we mentioned above, this is a highly debated topic and there are multiple approaches to balance good air quality with energy-efficiency. If you have questions or want to know more, feel free to reach out to our team here at AE Building Systems. We love to research the latest and share our knowledge on the techniques, as well as top products to use in your next kitchen project. 

Form AND Function Win Out When it Comes to European Windows & Over-Insulating

Get a Little Help From Our Friends!

We can learn a thing or two from seeing how things are done in other places. In the case of window and insulation design, European Windows with the combo of over-insulating is one of these smart solutions we glean from our European friends. The combination of this window design plus this technique in window insulation is a smart, practical solution that also provides some great aesthetic designs as well. We’ve seen it applied for so many reasons, but in the end, homeowners absolutely LOVE the way this combination functions, as well as how it looks!

A Passive House Win!

European windows have become a common practice in the Passive House movement, or for those that want a Darn Good House as we call it. They are often seen as a more sustainable option from the perspective of energy loss. Passive House projects are focused on increasing efficiency and in these cases, every little bit of energy reduction matters greatly. We see many Americans employing this style of window in their home even though it’s not the common practice around the country. Those that build Passive House buildings know that European Windows are one of the best-kept secrets that pay off big time! 

European Windows & Over-Insulating

European windows are often triple-paned, or even quad-paned, making for even greater energy efficiency. They also open inward, rather than cranking open to the exterior. As a result, they lend themselves easier to over-insulating techniques. The over-insulating techniques and materials are a natural fit for this style of window. 

The over-insulating can be applied to the head and legs/jambs, but not to the sill. The sill typically has weep holes that cannot be covered. 

American-Style Windows & Over-Insulating

The more common US-style windows are only double-pane, and often open outward or are casement windows. Because they open outward, casement windows are generally not designed to be over-insulated. You can’t cover the operable window sash, so the amount of insulation on the exterior surface of the window is limited. You simply don’t see over-insulating done with most US-style windows. So, for many of our customers, they really only think about over-insulating with European windows and often in the situation where they’re building with Passive House/energy-efficient practices as the main focus.

Function AND Form!

Not only are European Windows ideal for over-insulating from a function standpoint, but they look good too. Over-insulating makes the frames of the windows appear smaller and lower profile from the outside of the structure. This gives a more sleek, modern aesthetic, which is quite popular in today’s design. In the case of over-insulating with European Windows, form AND function are equally the winners!

Putting It Into Practice:

Smartwin® by Advantage Architectural Woodwork is a popular choice for Passive House windows, with their innovative, slim frame. They feature a flush-mounted sash internally and an all-glass look to the outside eye. These windows were designed from the start to be over-insulated. 

It’s pretty safe to say that if you’re considering a Passive House, or just a Darn Good House, that works as efficiently for you as it can, the windows matter. And, because the windows matter so much, you should also consider over-insulating European Windows. Not sure where to start as you discover the right window design for your home? Talk to our team. We LOVE sharing ideas and research around the latest and greatest options.

Project Highlight: Kirsch-Stroupe Residence near Winter Park

Project Highlight: Kirsch-Stroupe Residence near Winter Park

What do you get when you cross motivated homeowners, with sustainable builders, and an interest in Passive House design? This special combination is the bones for a truly special residential project up in Tabernash, CO near Winter Park for the Kirsch-Stroupe Residence. This project is a collaboration between Matt Kirsch and Kerri Stroupe, Bishop Built, and other Passive House Partners. The results so far are amazing!

As we write this article, the house is still in process. (We can’t wait to see the final product!) However, because it’s in process, we can see so much of the careful work being done to make this house as sustainable as possible with Passive House best practices. It’s been pretty fun to see the work that goes in, in order to make the final product work and run efficiently. 

The Players:


Ultimately, the desire to pursue sustainable and efficient Passive House strategies has to be a core value for the homeowners, especially in a difficult climate like Tabernash (one of the colder areas of Colorado). Matt and Kerri had a deep desire to live in an energy-efficient home and have an ongoing passion for a more sustainable lifestyle. 


Zane Bishop, of Bishop Built, has been an integral part of this project and stepped up to the plate! As the contractor, he has the obvious role in making the building a reality. Bishop Built has been building homes since 1982 and has a reputation for premium craftsmanship, clear communication, and full accountability. However, Zane also took Emu’s Passive House Training Class, which meant that not only was this a great construction plan for the home (also a part of Emu’s Pilot Program), but it is a sustainable one as well. This is huge for the Granby/Winter Park area as the Bishop Built team raised the bar in what local contractors can, and do, offer!


Our team at AE Building Systems had a small role in this project, as a supplier for SIGA products.  As a belt and suspenders approach, the project leveraged both the Majrex interior system and Majvest exterior system to help achieve Passive House airtightness levels. We also were available to support the Bishop team and answer any questions that arose around the products. While our part feels small, our emotional investment in the success of this project has been huge. And, we’re so thrilled for the Kirsch-Stroupe’s to enjoy their Passive House soon!

Another great partner on this project is Front Range Fenestration. They installed the windows and are great for window installations in the Rocky Mountain region. We’ve worked with them for many years and loved being on the team together for this Kirsch-Stroupe Residence!

Project Features:

While there are countless areas where this project has leaned into efficient practices, a huge focus has been on air sealing and insulation. This is a common thread on any Passive House project. As you can see in the photos, this part of the construction was not just a quick blip, but an intentional focus. For example, double-stud walls allow for increased insulation and reduced thermal bridging. In addition, SIGA products were utilized heavily to provide airtightness and reduce air infiltration.

Project Flow:

Any construction project needs forethought to ensure that the project flows properly. We’ve seen supply chain issues in the past couple of years that continue and have been a significant concern into 2021. When you’re considering a Passive House project, you need to make sure you’re managing timelines and milestones even more. Sequencing was a major consideration and every aspect had to be considered months ahead of time. Communication with subcontractors on the schedule was a huge puzzle to solve and manage, but so far has been a success. 

Find this project intriguing? You might be dreaming about a passive, sustainable home in the future and we want you to know that, yes, it’s possible! Beautiful homes that fit these efficient building standards ARE possible and possible here in Colorado. If you’re dreaming about that future home, talk to our team! We can help educate you, as a consumer, on what materials (like SIGA which was on this project) are helpful to consider. 

If you’re a builder and want to offer more sustainable and efficient Passive House building options for your clients, make sure you talk to our team as well. We nerd out daily on the latest and greatest approaches available. We love to pass on that knowledge. Not only that, but also check out EMU’s Passive House Trainings and consider leveling up your own knowledge on these innovative building strategies. 

Follow Bishop Built on Instagram:  @bishopbuilt 

Follow EMU on Instagram: @emubldgscience 

More construction and detail shots:

Indoor Air Quality During Wildfires

Smokey the Bear teaches us to help prevent wildfires, but Passive House Design and ERVs help teach us what to do to PROTECT indoor air when a wildfire is already happening! Those of us out west are no strangers to wildfires. They’ve become a regular topic of conversation in the summer months, and can be a crucial focus when living in the mountains. We often think about fire mitigation with trees and bushes, or having go-bags ready and a plan in place for evacuation. However, we don’t always think about how to protect the air we breathe when we’re living with wildfire smoke. And, when it happens, it’s something we simply can’t avoid. 

“Climate change has been a key factor in increasing the risk and extent of wildfires in the Western United States. … Once a fire starts—more than 80 percent of U.S. wildfires are caused by people—warmer temperatures and drier conditions can help fires spread and make them harder to put out.”

Normally, we think about incorporating outdoor air to improve indoor air quality. But when a wildfire is occurring, the outdoor air quality is often much worse. 

We have to think a little differently about how to maintain quality air indoors… 

A Few Breathing Basics For Better Indoor Air Quality During Wildfires:

  1. Stay indoors as much as possible when wildfires are running rampant. In this case, indoor air is going to be more healthy than outdoor air. 
  2. Keep windows and doors shut as much as possible. 
  3. Wear a mask if you DO need to go outside. The US EPA recommends an N95 or P100 respirator mask with a NIOSH label.
  4. Window air conditioners should not be used during wildfires, unless their outdoor air intake can be closed.
  5. Consider a portable air cleaner to complement air sealing and filtering measures during a wildfire.
  6. Focus on airtightness. Leaks and openings are ways contaminated air can get in. This is where the Passive House design is a huge benefit. Many build this way for energy savings, but in this case, Passive Houses have a leg up on traditional construction in that they prevent contaminated exterior air from coming in. Listen in on a roundtable discussion where experts discuss how Passive House strategies can help.
  7. Use an ERV to help recirculate and preserve the quality of indoor air. This last tip seems a little confusing if you know how ERVs typically operate. We dig in deeper below!

Should We Use An ERV During Wildfires?

One big question we get is if ERVs are helpful when wildfires are happening. ERVs pull air from the outside in, so at first glance, this seems like something you’d want to avoid. However, experts say it’s actually still good to run the ERV. We need oxygen, and need to keep CO2 levels down. When we have too high of CO2, it can impact cognition, loss of consciousness, and even death. 

Filters Used to Stave Off Wildfire Smoke

With the CERV2, the MERV 13 filters are considered sufficient to filtrate outdoor air – even during wildfires. The MERV 13 filters are much better than the MERV 8 filters, which are generally found in most ERVs. There is no need to add an additional filter to the inlet on the ERV during this season. What many people DO consider is changing to carbon or Colorfil filters to absorb additional odors and VOCs while smoke and ash are prevalent.

Automatic vs. Manual Ventilation

Operationally, when a wildfire is occurring, users can disable the VOC sensor from triggering ventilation and therefore would only be triggered by the CO2 sensor. If the smoke is extreme, or lasts for longer periods, you could also disable the automatic ventilation and manually ventilate with the system. For example, if it’s less smoky in the mornings, you might manually vent the system for an hour or so and then shut the ventilation off for the remainder of the day. With the CERV2, you can do this with your phone, tablet or computer and from afar. You don’t have to be home to adjust the controls. The main operational change to make would be to disable the VOC sensor from triggering ventilation and only go by CO2. During extreme smoke periods you may want to totally disable ventilation and then just manually trigger ventilation periodically. The pollutant sensors keep reading when disabled, so you will still see your IAQ data to know when to ventilate.

Recirculating Air to Maximize Indoor Air Quality

The CERV2 allows you to recirculate air. When you’re dealing with poor outdoor air quality, it’s important to recirculate indoor air as much as possible. This will continue to filter the inside air, further filtering any air that originally came in from outdoors. 

Wildfires and Passive House Principles 

The most effective strategy against particulate matter during a wildfire is an airtight building envelope. We achieve this by building with Passive House strategies as well as the strategic use of a CERV2 unit. Over the years, we’ve seen so many benefits to constructing home systems this way, but the recent wildfires, and the resulting poor air quality, make for an even stronger argument to focus on Passive House design for your next build! 
What else have you done to protect your home and air quality during wildfire season? Reach out or comment to let us know. And, don’t miss the conversation over on Instagram around this topic and more around sustainable, energy-efficient construction!

Passive House Air Infiltration Hot Spots

Building a sustainable building envelope is easy…until you add in openings. Wouldn’t it be nice to be able to make efficient building envelopes in a snap? But that’s not how life works. We need doors and windows and vents and openings in order for a building to function. So, alas, we have to deal with holes in the building envelope that complicate our lives, especially when we’re working to build with Passive House practices in mind. But with each hole we make in a building, we need to pay attention to ensure there is minimal air infiltration.  

Why Should You Care?

Every hole in a building envelope is an area of extreme complexity. It becomes an area where you have to focus structural attention to ensure that it functions properly, but it also becomes a juncture for energy (heat) and air to escape. When it comes to Passive Home tactics, we care about this a lot because these junctures are usually where most of our inefficiencies come into play. Therefore, we need to make sure we pay special attention to these areas to ensure that we can maintain an efficient, effective structure. 

We don’t care just for the sake of being more efficient, but also because if not done correctly, it can lead to future problems. Thermal bridging can occur when openings are not managed properly, causing condensation, warping, and other long-term effects that can damage a structure.

Top Culprits for Air Infiltration Issues:

[And What You Can Do!]

Bath Vents: 

Bath vents are often overlooked and forgotten about as they serve an important, but often invisible role. The mix of moisture management from showers, coupled with the fact that it’s a hole to the exterior elements, means this can be a significant energy loss location. 

For a more Passive House approach consider using:

Dryer Vents:

Clothes dryer vents are another big culprit when it comes to air infiltration and inefficiencies. This necessary vent can cause some major issues considering the appliance is often NOT in use. 

For a more efficient approach:

Range Hoods:

Another big spot where air quality can get iffy inside the home is in the kitchen around the range. Gases and toxins in the air from cooking can be harmful if left to linger in the home, so proper ventilation is vital. 

For a Passive House Approach:

  • Leverage the CERV2 and ducted range hoods to help evacuate air from the kitchen. 


We don’t always think about lights being an air infiltration trouble spot, but lights can be openings in the envelope where air can leak

For a more efficient option:

  • Use LED puck lights instead of traditional (leaky) can lights.
  • Choose air-tight can lights whenever can lights are absolutely necessary.

Plumbing Stack Hole:

When we think of plumbing, we think of water not air, but the plumbing stack can be a huge culprit for air infiltration. The venting holes, usually in the roof, require flashing and regular maintenance to ensure they are not leaking. Since they’re on the roof, it’s not uncommon for debris to clog these, causing more air quality issues and lack of actual venting. 

For a Passive House Solution Instead:

What else can you do? 

It’s impossible to avoid having some holes in your building envelope. So wherever you have openings, it’s vital that you have focused attention to how the openings are constructed. Bring in expert opinions on Passive House Construction to see where you have opportunities (Like the CERV2, for example) to be more efficient and smart in your systems. Another important step you can include in the construction is using SIGA Tape for high-quality air sealing

Ultimately, the best approach to managing air infiltration at openings and holes is with a proactive approach. The more legwork you do up front, the fewer surprises down the road and the more efficient your building envelope will be. If you’re working toward a Passive House design, focusing on air infiltration is an important item that needs to be on your checklist. We’re here to help on your next project. Make sure to hit up our team to see how you can improve the air quality in your upcoming Passive House project! 

Breathe Easy Inside: Air Quality Improvement with CERV2

Ready to breathe easy? Air quality has become more and more of a focus in recent years.  It has more than just mental benefits; air quality has a direct correlation with our physical well-being. Those of us in the construction industry have known this for years, but recently with COVID-19, the world is now aware of how your indoor air can affect your health. 

Dwelling Inside

People often think about air pollution being an outdoor issue, but indoor air quality is actually a larger threat to health. The EPA states that indoor air can be up to two to five times (sometimes 100 times) more polluted than outdoor air. In the United States, people spend about 90 percent of their day indoors, 70 percent of that in a residential home. The Environmental Protection Agency (EPA) actually calls indoor air pollution the #1 pollution problem in America.


75 million people in the United States have a medical diagnosis of allergies and asthma or both! Indoor air pollutants like pollen, mold, and other contaminants can affect air quality. Internal sources include combustion and make-up air for appliances, bath ventilation and general infiltration through unsealed openings. It is among the country’s most common, but overlooked, diseases. 

Allergens can be mitigated through careful home design, thoughtful construction material selection, quality construction tactics, and other lifestyle choices. The use of wireless sensing equipment, automated pollution monitoring, strategic ventilation systems (CERV2), and high-efficiency (MERV) air filtration systems can remove up to 99.6 percent of airborne allergens. 

Proactive Construction

At AE Building Systems, we work with our customers to provide effective construction materials and systems to build homes with good air quality. That’s why we love the CERV2. This ventilation system offers high-efficiency ventilation, while removing contaminants from the indoor air circulation. Our focus is always on proactive systems for healthy, sustainable spaces! 

Below is a testimonial from one of our customers who used the CERV2 in their recent project: 

“Both my wife and I work from home and suffer from pollen allergies. We wanted to minimize the health issues allergic reactions cause us both. To do that we integrated a computerized energy recovery ventilation system, CERV2, from Build Equinox into the home’s HVAC system. When we built our new home we integrated smart ventilation and air quality monitoring into the home’s HVAC system.

After moving into our new home, we were delighted to discover that our allergy symptoms disappeared. We slept better, had better brain function, less illness’, were free from sneezing and inflammation. It was transformational.

New homes are built very tightly and sealed from air infiltration. They do not “breathe” like older construction. Many areas, including Denver, require passing with a blower door test score of 3.0 or better prior to issuing a certificate of occupancy. A home with a blower door test score of 3.0 or below is a very tightly built home and needs ventilation to maintain quality indoor air.  

We chose the CERV2 for a number of reasons. It is a smart ventilation system. It continually monitors for volatile organic compounds and carbon-dioxide (VOC’s and CO2). When user set thresholds are exceeded for these pollutants it automatically begins ventilation. The ventilation process filters the air through 2 separate Merv 12 air filters. The 2 Merv 12 filters remove almost all airborne contaminants.”

-Craig Tessem, Colorado

If you’d like to learn more about how to promote healthy indoor air quality, talk to our team to learn more about the CERV2 and other products that prevent air pollution and help you create a space you can truly breathe easy in!

Feeling Thin is a Win With Alpen Thin Glass

You know that feeling when you try on your old Letterman Jacket, or the jeans from ten years ago? It feels GOOD to fit into the same size, right?! That same feeling is what we get when we fit triple pane windows in the same standard size of a double pane window and get even more performance! 

Okay, okay… maybe that’s a stretch. BUT, it’s the truth. Alpen’s new Thin Glass technology now makes it possible to get even higher performance out of our windows without significant increases to size and weight of the windows. That’s a BIG DEAL when it comes to constructing high performance and passive houses!

What is Thin Glass?

Alpen is excited to share about their new Thin Glass design with the world and we’re excited to share it with our customers too. This new product is changing the face of high-performance windows and offering great solutions for building projects. Alpen uses a triple-pane window, which utilizes thin glass as the center pane. Historically, double pane windows were really seen as the industry standard, and utilizing thin-film helped increase the performance. However, using a thin glass pane, Alpen is able to increase the R-value while maintaining the same industry-standard thickness of the window. The new style only increases the weight by 12 percent, and allows for possibilities for a quad-pane option that only adds 17 percent.

What Makes Thin Glass So Great?

Thin Glass is proving to be an innovative product for so many applications, but let’s take a brief look at the big benefits:

  • The use of thin glass for the center panes provides some of the most energy-efficient windows on the market today. Superior U-factors, increased condensation resistance (CR) and increased visible light transmission (VT)!
  • The cost is currently the same as using thin-film, yet with improved performance.
  • Tested and verified by the National Fenestration Rating Council.
  • Multiple glazing options available.
  • Crafted in the United States at local facilities with specific manufacturing space dedicated to Thin Glass production.
  • Paired with Quanex Super Spacer for even greater performance! 

Thin Glass & Thin-Film: Cousins in the Industry

Thin Glass is a comparable product to Thin-Film, both made by Alpen and both great options. Thin-Film has been Alpen’s go-to for many, many years, and will still be available for many of their top lines like Zenith and Tyrol. Suspended film still provides excellent insulation and R-values, while providing the lightest high-performance windows available. Thin Glass and Thin-Film are like cousins in the same family:  providing the same functions (at a comparable price) but are slightly different.

Thin Glass is set to shake up the world of high-performance windows. Customers are always looking for the best performing window options, regardless of the climate, and innovation like this sets the bar high. Whether you’re working toward a truly Passive House model, or just looking for a more efficient solution, Thin Glass technology in windows like Alpen’s is a great option! Check out Alpen’s product lines over on our website.

Working Alongside Nature with the Stack Effect

We’re always trying to work smarter, not harder, right? So, that begs a BIG question in construction of why we have worked so hard to heat and cool houses for so many years! So much of our modern mechanical systems and building design ignores very simple ways to heat and cool a space. Instead, if we focused on utilizing passive ventilation practices, our homes would work more FOR us rather than making our systems work for them.

What is Passive Ventilation?

Passive Ventilation often refers to the natural process of creating airflow by working with natural properties of heat rising, and pulling cooler air through lower windows. This is known as the stack effect and is achieved with the use of high windows that allow warm air to escape, and lower windows that pull in cooler outdoor air. The natural rise of hot air and pulling the cool air up through a space makes for a passive ventilation pattern in a space. 

There’s a lot more going on than just hot air rising. There’s a lot more going on than you might first think. When air inside a building is warmer than the outside air, the warmer, less dense air will rise. Depending on the season, the way wind approaches a structure, the height of the structure and number of floors, and other minute factors, the pressure is going to differ. As a result, buildings that utilize the chimney effect of passive ventilation are often nicknamed “breathing buildings.”

Residential AND Commercial Use

Passive Ventilation has been used for years upon years without even putting a ton of mathematical calculation to the process. One example you’ve probably seen is when older homes often had transom windows in bedrooms above the bedroom door. This was a simple example of how historical home designs understood the need to ventilate an individual room and help the hot air escape when needed, and to close it to trap in heat in the alternate seasons. Proper placement of windows or even skylights on upper levels of homes can then be a great way to let the warmer air escape the home and create a natural flow of air.

For example, in Colorado where we are located, many homeowners are able to live comfortably without air conditioning by utilizing these techniques specifically at night. Night flushing can allow cooler air to enter a home with lower level windows and force hot air out with second or third level windows or vents. Since our temperatures cool down significantly in the evening, homeowners can flush out the hot air that has built up throughout the day from the building’s structure. Materials like brick and concrete take longer to absorb heat throughout the day, which can also help stabilize the internal climate on a hot day. 

Passive Ventilation is a great answer for not only homes, but for larger buildings as well. The main method is to provide ventilation stacks within the building that ideally have a method of flow control in order to adjust as needed. Sometimes these systems benefit from having a backup mechanical ventilation option as well to make up for times when there is overventilation or underventilation. 

Is the Stack Effect the Answer Everywhere? 

While utilizing the Stack Effect can be a really smart solution for so many spaces, there are definitely some scenarios where it’s not ideal. One example is in colder weather or colder seasons. In these scenarios the heat is a desirable component for a home and pulling hot air up and out actually has a negative effect. High temperature difference between the building interior and exterior can result in overventilation and unwanted building heat loss.

Another scenario where this is not ideal is with high rise buildings, where the higher up the “chimney” of the building, the greater the pressure. The pressure was so significant when skyscrapers were first introduced, the revolving door was invented because the pressure in the building prevented normal doors from opening. 

As mentioned above, sometimes a mechanical system may be installed to help regulate the internal pressure and temperatures. So while passive solutions are often a great way to save on energy costs, it’s not a perfect solution for every season of the year and every location. That said, the energy savings that CAN be gained by employing a passive ventilation system can be significant and one that makes a lot of sense. 

If you’re wanting to work WITH nature, employing the stack effect could improve your project greatly. Our team is always here to help you maximize your options and consider how windows and intentional openings in your home may not only add to the aesthetic nature of your home, but also help you with smart ventilation as well. Drop us a message to discuss!

Modern Farmhouse With a Passive Twist: Profile on Greg Fisher’s Millhaus

Modern Farmhouse With a Passive Twist: Profile on Greg Fisher’s Millhaus

Long before the modern farmhouse was a trendy term on HGTV, an architect had a vision for design that had a connection to nature, history, sustainability, and all-around innovative design. Greg Fisher, architect based in Fort Collins, Colorado, embraced the concept with his home/office, which has become known in the Passive House community as an example of innovative design with sustainability at heart. 

The Millhaus

Millhaus is a Passive House project that combines Greg’s personal home, as well as an architectural office that was named for its history as a mill, and the nod to Passivhaus design. Built on the property of a former cherry mill, the 3200 sq. ft. structure became a collaboration between traditional, gabled design, modern aesthetics, and Passive House principles. The house marries traditional materials native to the original structures of the mill with more modern materials like steel. Greg’s project truly personifies his belief that “aesthetics can be part of Passive House.”

One-of-a-Kind Features

It’s not every day that you run across a home that utilizes these features:

  • History: The property has a long-standing history as a cherry mill. This is a factor that added story and soul, and a starting point for Greg to launch his design. In fact, the kitchen pantry is modeled after the tool crib from the mill. Greg has plans to enclose that here soon, but at the moment it is just an open-shelving section of the home. 
  • Unique Walls: The wall cladding on this house is actually tree bark shingles (a cradle to cradle product). Talk about a connection with nature! 
  • Breathing Easy: Greg incorporated high-quality ventilation solutions to promote energy efficiency and healthy indoor air quality.  
  • Fully Grounded: The home features a two-ton ground source heat pump, which contributes to a more passive approach to heating. The tax rebates aren’t a bad incentive either! They also combined that with radiant floor heating. 
  • High-performance Living: This home features a blower door test value of ACH50- 0.44. The lower the ACH50 values, the tighter the building. Greg’s home ultimately is extremely air tight, maintaining temperature and climate throughout. 
  • Goodbye Dry Skin: Unique to Passive air-tightness, combined with the use of an ERV in the house means that the house is kinder on the skin, especially in the dry climate of Colorado! 

Passive House Products:

Greg’s nod to the Passivhaus design in naming his project “Millhaus” does not go unnoticed to those of us in the Passive House construction community. This project is a fully certified Passive House project. His project features some amazing products:

  • Advantage Smartwin: Throughout the home, fixed, tilt/turns, and swing windows, as well as lift/slide doors were used. They feature Euroglass and offer high-performance design at the openings. They focused heavily on the window to wall ratio and measured that carefully to work with the orientation and sunlight. 
  • Alpen 925 Series Windows: While Advantage windows were used primarily, there are a few locations where the Alpen 925 Series Windows were used. We’ve used these in so many projects and love not only the quality, but the maximum performance they deliver. 
  • SIGA Air/Weather Barrier: Millhaus features the use of both Majrex interior system and Majvest exterior system for achieving the Passive House required air-tight standard.
  • Sequencing:  Emu Building Science (Enrico and Mariana) provided sequencing assistance for the Majrex interior application. [Watch for a more in-depth examination of the power of sequencing on our blog!]
Passive House Weather Barriers by SIGA

The Millhaus is a true example of how great design can meld with sustainable principles. If you want a Passive House design, you can still have an interesting and well-designed home. We love the innovation we’re seeing come out of this movement, and we love helping our clients make innovative decisions for their next project. Talk to our team today and start brainstorming about how great design can truly be passive too!


We have the privilege of being able to hear directly from Greg Fisher about his amazing project. You can hear his approach and more details about the home on the BS+ Beer show’s interview  from Dec 11, 2020 – Millhaus: A Mild Climate Case Study

Shopping Local Never Sounded So Good!

Expanded Capabilities with Alpen’s New Manufacturing Facility

Shopping local and supporting local businesses has become a big concept in our world, and as a small business ourselves, we love that so many people want to support local businesses like ours. It’s even more exciting when we can also support local businesses in the products we offer, which is why we’re so excited about Alpen High Performance Products! (And, with their recent move to a new facility in Louisville, Colorado, they’re literally right around the corner!)

Alpen is a U.S. based window and door manufacturer that offers some of the most energy-efficient fenestration products you can get today! They have over 40 years of experience, which has led them to be an industry leader. We’re proud to carry their products, equipping our customers to build energy-efficient buildings. 

Alpen recently moved to a new facility in Louisville, Colorado (voted a top city in the U.S. to live!) as part of their long-term growth plan. This new facility is 59,000 square feet and is nearly 40 percent larger than their previous facility. 


They’ve now combined their glass (IGU) fabrication, frame fabrication, and paint divisions all under the same roof. They’ve also created space for a larger shipping and receiving dock and updated offices. What a difference this will make for faster communication, better understanding of the various processes, and ultimately a better result for our clients! 


One of Alpen’s investments within this new facility is machinery to automate manufacturing processes. They’ve invested heavily in automation machinery and equipment in fiberglass cutting and drilling, uPVC welding and paint functions  – something their old setup did not include. 

Greater Capacity

The increase in space and streamlined production allows for Alpen to run even more efficiently. The new facility also provides for increased IGU production, which can now be manufactured in the same space! They have also increased their production capabilities for fiberglass frames, plus improved paint booths and plasma prep on finishes in this new space.

Quality Control

Having every department under the same roof allows for greater quality control. The Alpen team has added staff and improved training, tightening their quality control procedures. Alpen has also put a tremendous amount of focus and energy into the fiberglass paint and painting process they will be using moving forward.


The Louisville facility also has room for a new showroom that is in the works. Given the proximity of the new facility to many of our clients, we’re excited to be able to showcase the latest products and offerings from this leader in energy-efficient windows and doors! One of Alpen’s new products includes the WinSert window insert! More information will be coming regarding this exciting new product for energy retrofits.

Certified Excellence – Continued

The new facility is also exciting because Alpen is the first US manufacturer to be PHIUS certified, and the first North American manufacturer to be dually certified by both PHIUS and PHI. Alpen will continue to manufacture these high-performance fenestration products in their new facility.

What does this mean for us?

This facility upgrade means better communication, enhanced quality control, greater throughput, and shorter lead times resulting in improved products moving forward. All of this means a better experience for our customers. The fact that we’re just a hop, skip, and a jump away from this new facility makes it even more fun for us to develop and grow our long-standing relationship with Alpen. 

We’ve been selling Alpen products, like the Tyrol and Zenith lines, for around seven years. We’re excited to see the new innovation that comes out of this brand as they move forward. More than that, we’re excited to offer our customers a great experience as a result of this new facility and the great team over at Alpen. 

Curious to see how Alpen windows and doors can support your next construction project? When this 800-pound gorilla called COVID is under better control, we will look forward to scheduling a factory tour.  In the meantime, please chat with our team to see how you can get the very best in energy efficiency from not only our local company, AE Building Systems, but also from a local manufacturer, Alpen High Performance Products! 

Please contact AE Building Systems by calling 720.287.4290 or emailing

The Rise of the ADU: Increased popularity AND energy efficiency

Call it a Granny Flat, a Mother-in-Law Suite, a She Shed, a Man Cave, or whatever you want, an Accessory Dwelling Unit (ADU) has become the BIG THING in residential architecture today. ADUs have become a popular feature in homes from city neighborhoods to rural properties, and they make a lot of sense when you dig into the benefits. What we’re seeing, though, is that people not only want to build these additional living spaces on their property, but they want to build it in an efficient manner so that it works for them in the long term.

What is an ADU?

An ADU is an additional living space added to a property, containing all the essential functions of a normal house. They are a solution to the need for affordable housing, population density, and multi-generational living solutions. As the need and interest has grown, many local governments are passing new laws and regulations, allowing for more homeowners to build and rent ADUs. 

Why are ADUs so popular?

ADUs have risen in popularity in recent years for many reasons. Here are just a few of the top reasons why people are considering adding this accessory dwelling to their property:

Sharing Economy: As sites like Airbnb and VRBO become more popular for travelers or short-term renters, there is a need for smaller living spaces that are versatile. These are great income generators for existing homeowners.

Aging Population: As Baby Boomers become the largest aging population we’ve seen, many seniors are opting to live near their family but not fully with their family. ADUs make that possible in a simple way. 

Affordable Housing: Many municipalities have experienced higher housing costs, and the shortage often falls in the category of smaller apartments and affordable options. Adding more ADUs within existing neighborhoods allows for a simple solution for employees to live near where they work. 

Tiny Living: Most ADUs are smaller in nature (compared to the main house on a property) and are often less than 900 square feet. The recent popularity of tiny homes and minimalism has made this smaller living style more popular at large. 

Increased Property Values: An ADU increases the property value significantly. It’s an investment in a property that easily brings in a return, so it’s often a no-brainer for homeowners who are considering adding an ADU. 

Passive Income: Long-term renters are looking for an alternative to multi-family units such as apartment communities, especially during COVID-19, and a sense of their own space that is not communal. ADUs are a source of passive income to families.

Work From Home: With so many employees working from home (not to mention all the kiddos doing school from home, too), many Americans have turned their ADU into a home office space. An ADU gives you options! 

Don’t Just Build an ADU… Build an ADU That Works For You!

Many people get excited about the prospect of building out an ADU, but they don’t realize that by building an energy-efficient structure, they can actually make the building work FOR them even more than they thought. 

Waste Not Want Not

Suppose you’re using an ADU with renters, whether short-term or long-term folks, you don’t always get people who care about decreasing their energy load. Depending on the rental situation, you don’t necessarily charge renters for utilities. If you build an ADU that incorporates energy efficiency, one with passive house principles, and is built to last, you can help offset your investment. Instead of spending your income gained on utility bills and other regular maintenance projects, you can pocket that money as income or pay for the investment quicker! 

Thinking Outside of the Box

One of our friends, Bill Lucas, decided to build an ADU as a second level to his detached garage in a city neighborhood. While he built the structure with a lot of energy-efficient methods in the insulation, wall structure, window selection, and roof selection, he also considered how his ADU could help make his main house more efficient too. His main house is an older home, and the configuration/layout of the roof did not allow for the use of solar panels. However, the roof of the ADU DOES allow for solar panels. As such, he configured the electrical wiring so that the solar panels on the ADU can not only support the ADU itself, but also help cover the electrical load on the main house. Check out this tour and interview with Bill Lucas to get an insider view of his project.

Do the Right Thing

For many of us building energy-efficient Passive House buildings, we do it largely because it’s the right thing to do. Many homeowners building a brand new Passive House will add an ADU into their design and are intentional about making sure the envelope of every aspect of the build is done right from the start. Many homeowners retrofitting an existing space realize the shortcomings in the original structure and want to build the new ADU the right way from the start. 


Have you ever stayed at a really unique dwelling? Many travelers purposely seek out unique situations to stay in, like converted lighthouses, treehouses, and other extraordinary spaces. While your ADU rental might look like a normal house to the naked eye, it could be a great educational tool and a great marketing tool for future renters. Educate your renters on the features of the home, the story of the ADU, and some simple things that can be done to retrofit any space to be more energy efficient. 

Here are just a few of our favorite rentals that are not only leveraging their energy efficiency, but they are also educating in the process. 

  1. Award-winning Passive House on secluded mountainside
  2. Phoenix Haus-Powderhorn Mtn Resort 
  3. Earthship Off-Grid Rentals

If you’re considering adding an accessory dwelling unit (ADU) to your property, now is the time to dream. Go explore what others are doing to get ideas. See if there are ways you can leverage the structure to work for you, as well as your pocketbook. See if there are out-of-the-box ways to build the structure so that it works even smarter for you in the long run. Do your research now to make a smart plan for your ADU! 

Remember, we’re here to help. Together, let’s think through different options for construction, energy-efficient materials, and what people you need on your team. We enjoy dreaming with people about their next energy-efficient space, and we’d love to do it with you!

Adventures in High-Performance Windows & Building Envelope Construction

When we moved into our home, it was an adventure! As we got to know the neighbors, we’d hear stories about the former owner. One such story included how the elderly woman would go away for a week on vacation and leave all of the wooden crank windows wide open so that her cats could come and go as they pleased. What did this mean for us? Well, for one thing, you could literally see the light streaming through the frame because the wooden window frames were so warped from the elements all season long. 

Needless to say, one of the first projects we tackled was replacing ALL windows to high-performance windows. We know we’re not alone here! Most homeowners come across energy loss from their windows after moving into a new home. Often, they blame it on drafts in the home, or simply settle for the fact that stratification and convection currents are part of their lives. But, it doesn’t have to be this way!

Why do high-performance windows and high-performance building envelopes matter? 

  1. Conserve Energy: High-performance windows and building envelopes simply don’t waste resources. But when you have major thermal bridging, stratification, etc. you are paying to heat/cool a space as well as the outdoor space surrounding your home. You’re literally wasting energy every single day. (And, sadly, we see this in both new builds AND retrofits too.) 
  2. Running Out of Resources: Our world is quickly burning through common energy resources. In a few hundred years, we will largely deplete our in-the-ground energy which was created over hundreds of millions of years. Much of the coal, oil, and natural gas derives from decomposed plants (photosynthesis) and animals from long ago. We hear people refer to that energy as prehistoric solar energy.
  3. A Mess For Future Generations: Do we care about how we’re leaving the earth for our childrens’ children and beyond? Literally burning through resources does nothing to help our future generations. 
  4. Climate Change: Stay with us here…whether you have given into the politicized side of this or not, our climates are changing around us and there’s scientific proof to back it up. Using less energy resources to heat and cool our homes is a simple way we can help make a dent. 
  5. Save $$$: If you’re not convinced already, maybe saving a ton of money will help get your attention. Using less energy to heat or cool a home by using high-performance windows and building envelopes means less money you’re spending each month. Some parts of the country and world experience this more than others. For example, homeowners in the Northeast spend roughly 1.5-2.5 times more in energy costs than residents in Colorado! Of course those numbers are changing constantly, but it’s a good picture of how smart building systems can make a difference!
  6. Future Savings: As energy costs increase (which they regularly do and will continue to do as traditional energy sources deplete), your costs can stay more normalized. The more energy-efficient your home is, the less you flux when prices change in energy. High-performance windows/building envelopes are kind of a hedge, if you will, against rising energy costs. The 625 windows will help as well, but 925 will help even more. 
  7. Peace and Quiet: The higher the efficiency of your windows and envelope, the greater privacy and “peace and quiet” you’ll have in your home. Whether you have a baby sleeping, work from home, or just love some silence, high-efficiency windows can make a great impact. 
  8. Greater Comfort: Most importantly, your house will be more comfortable. You will have fewer drafts which are actually more often convection currents. Also, you will be able to read a book next to a window in the winter in a t-shirt without feeling the cold as much. There are a lot of factors that go into a “comfort quotient” and you can go into intense detail if you want on this. The main thing is that if you build for energy efficiency, your home will have less drastic temperature swings from zone to zone and you’ll be more comfortable while in it. 

Ready to help improve your life AND help out our world’s energy problems? Building with high-performance windows and building envelope strategies is just one simple way. It’s a win-win for all. It’s an investment on so many levels. If you’re considering this kind of construction, we’d love to help you find the perfect materials for your project.

For additional reading, check out this recent blog post on “Eco-Friendly Ways to Prep Your Home for Winter”

Breathing Easy with CERV UV

If ever there was a time where we cared about our air quality, it’s now. With the recent pandemic, airborne illnesses have caused a huge spike in air quality considerations for construction. Many universities are moving classes to occur in spaces that already have higher quality ventilation; plus, commercial spaces are retrofitting and improving their ventilation systems to meet higher standards, and everyone is aware of the air they breathe. So, it makes sense that people are also thinking about this in their homes too! That’s why the CERV-UV has been such a revolutionary product for our industry and why we’re loving the results it’s bringing to our customers. 

Breathe Easy With the Help of Build Equinox

Build Equinox released the CERV-UV Ultraviolet Air Purification this last year, which is the latest big addition to the CERV family. They’ve been researching the UVGI (Ultraviolet Germicidal Irradiation) in recent years, and have incorporated that learning to create the world’s first smart ventilation system that includes integrated UVGI. It’s smart, it’s healthy, and it’s innovating homes like never before! 

Effective Kill Efficiency

Ventilation systems have been notorious for spreading germs and contaminants that affect air quality in a home. CERV has done a great job at improving this, but the introduction of UV to their already great system has been a game-changer! How well does UV work? It all depends on the lamp power and air velocity. This system has selected the lamp power in relation to typical CERV airflow to achieve a good first pass kill efficiency of 85%. UVGI radiation breaks up genetic material in microbes, thus providing a deeper layer of health to your home. These microbes are huge culprits for allergies, poor IAQ, and airborne disease transmission. The CERV UV uses an 18W UVGI light source made of titanium oxide doped quartz glass, so it does not produce ozone either.

A SMART Solution

The CERV UV system is not only great for indoor air quality; it’s also a no-brainer when it comes to simplifying your life. Between their touchscreen panel and mobile app, you can maintain control from anywhere. You can also see analytics on your air quality at any time and manage parts and service options as well. 


The primary consideration to maintain a system like the CERV UV system is to remember that you’ll need to replace the bulb on an annual basis. This helps ensure that the UV light is working fully to your advantage. 

Interested in using this system in your home? 

Whether you’re looking at a retrofit scenario or a new build, the CERV UV system is a superb option. Our team can help you figure out what you need and what specifications to include in an order. We can also answer any questions you might have about your own unique situation.

Stop Settling For Stratification

We’ve come to know that some parts of a house are generally going to be hotter than others in the summer months. Certain rooms of the house bake, while others are nice and comfortable. Why do we settle? The truth is that no house needs to operate like this. When you understand stratification and convection currents, you quickly learn there are simple design strategies to help prevent temperature deltas within the home. 

Why are there problems in the first place? 

Homes often experience stratification. Depending on the weather conditions of the season, the temperature between a basement and second story of a building may vary 15-20 degrees. That’s quite a difference! We could share the complex physics behind this, but the cliff notes version is essentially a layering effect that allows pockets of air with different core temperatures to remain intact, even if a building’s central HVAC system is in place. Drafts and stratification are usually due to interior temperature deltas causing microclimates stratification and convection currents. You experience convection currents and stratification which often manifest as drafts in stairwells and around bad windows or poorly insulated walls and attics which often also cause cold floors. You end up with microclimates throughout the home and most people live this way without giving it much thought.  

But, what if we gave it some thought…???

The truth is that designers have been giving it thought for a long time, and we see it all over the strategies in a Passivhaus design. A Passivhaus, or even a Darn Good House concept, employs techniques that are focused on reducing thermal bridging, drafts, issues at openings, and more. While a Passive House design is focused on energy savings and passive strategies, a huge focus is also on effective insulation. When you have a solidly-insulated air sealed house you have an energy efficient house; these go hand in hand. The side benefit is that you end up with a home that has stable temperatures in both extreme hot and extreme cold environments, and from the lower levels to the upper levels in the home. 

How to Avoid Stratification:

  • Build a Passive House from the start. If you are working on a new project, take the time now to build a structure that is well insulated from day one. This will help ensure you can avoid convection currents and stratification. Your upper stories can be comfortable and similar to those temperatures in your basement level. 
  • Fix an existing problem. If you are working with an existing building that has issues, hope is not all lost. There are a few core things you can do:
    1. High Performance Windows: Replacing openings in the home with high performance windows and doors will help reduce the drafts and swings in temperature you experience throughout the home. 
    2. Continuous Insulation: Proper continuous insulation in walls becomes a solid barrier for thermal bridging. Often a little investment in insulation can go a long way to reduce drafts, energy loss, and ultimately stratification. One simple space to insulate that many don’t even think about is the basement/foundation walls, as well as the horizontal slab. 
    3. More Attic/Roof Insulation: One of the biggest energy penalties comes from poorly insulated and poorly air sealed attics and roofs.  Attics and roofs can account for as much as 40% of a building’s energy losses.  
    4. Air sealing: Find all the leaks you can and seal them up. It is hard in retrofit situations, but made easier with a thermal imaging gun and a blower door.  

We know firsthand how this works. Our owner, Todd Collins, purchased a great house in a great location, but it was built in typical 1970’s construction practices where, sadly, he experiences stratification on a daily basis. He’s combatted this by heavily insulating his attic and incorporating new energy efficient windows. It’s not a perfect solution, but it has helped significantly. We can’t always build a brand new home that is energy efficient from the start; instead we find ourselves working within the framework of a house we purchase. 

Over the years, our culture built homes that simply aren’t the most efficient… and unfortunately, we are still building marginally efficient homes.  However, today we have the knowledge to build highly energy efficient homes and structures. In turn, we’re less reliant on outside energy sources to regulate our spaces, AND we end up with more consistent comfort throughout the entire building. Quality building products and Passive House design strategies help to make any space more comfortable and more efficient. 

Why are Innies Becoming The “In Thing” For Energy Performance?

One of the big debates in construction sounds a lot like we’re talking about belly buttons, but we’re actually talking about window construction:  innie vs. outie! In construction this great debate has been going on for some years and it can be confusing to know what the right solution is for your project. Each style has been used in various ways over the years, but if you’re like us, and concerned about thermal performance and energy savings, you will want to pay attention. 

The Basics of Innie & Outie Window Construction

Outie Window Construction:

Outie windows are constructed with the glazing of the window set flush to the outside of the wall assembly – typically with a “nail fin.” These are the types of windows most Americans are used to seeing in a home. 


  • Easier Installation:  Installed with nailing flanges to the outer face of the wall. 
  • Deeper interior sill: Interior sill leaves a small ledge.
  • Simple Drainage: No exterior window sill to be concerned with.
  • Conventional looking: This is what most people are accustomed to, know, and understand. Many homeowners like to have a little sill to place plants or other decorations. 
  • Easier for continuous insulation: When windows are set on the outside, things line up more, and the water and control layer is the face of the continuous insulation


  • More thermal bridging: Since window assembly is on the exterior shell of the home, there are more thermal considerations to deal with. Often ThermalBuck is a good solution for this, but the simple fact of the location means higher heat loss and greater thermal bridging. 
  • More Instability: Since the window isn’t fully framed into the wall itself, and is instead screwed on with flanges, the window often just “sits in” the space, rather than is fully part of the wall like its counterpart. 
  • Wind-washing:  Because the window is to the exterior, wind will cool it down in winter and warm it in summer more readily. 

Innie Window Construction

Innie Windows are a window construction style where the glazing of the window is set at the middle of the wall. Many people enjoy the overall look of Innie Windows, but don’t even realize just how efficient they can be! Take a look at some of the pros and cons of Innie Window assemblies:  


  • Weather Protection:  Since Innie Windows are not on the direct outer surface of a wall, the window is protected more from rain and wind. 
  • Improved Thermal Performance:  Since the glazing is within the wall’s depth, the window at large is more insulated from the thermal envelope of the building. 
  • Greater Support:  Innie Windows are secured and supported by a full frame, rather than just screws on a flange. 
  • Solar shading: Recessed glazing provides greater shade from the sun throughout the day. 
  • Better thermal performance: The glazing being within the wall’s depth keeps the glazing within the insulated thermal envelope
  • Better for Passive House design: In Passive House design, every little bit of energy performance matters; ultimately Innie designs can help the overall performance of a home!
  • Aesthetic:  Some architects and homeowners prefer the look of an inset window.  
  • Wind protection: from “Wind-washing” 


  • Greater Complexity: An Innie Window is much more complex to install, as it creates concerns not only for the window itself, but for the exterior sill and surround. 
  • Require thick wall assemblies: Innies are not very common in 2×4 or 2×6 construction. Instead, you’ll find them in Double Stud designs, or Phoenix Haus wall assemblies. 
  • Exterior Sill Detailing Needs:  Requires a solid weather-resistant exterior sill and special considerations for this design. 

It’s easy to see why Innie Windows are becoming a more popular choice for builders. Windows are a hot spot for thermal bridging and while there are a lot of things we can do with insulation construction, supporting products, and the window product itself, we also know that if you’re going for energy savings, the placement of the window itself makes a big difference. It may only be a few inches in, but Innie Windows can provide a solid improvement in energy performance, especially if you’re going for a Passive House certification where every bit of help may make a difference between getting certified or not. 

Still not sure if Innie Windows are right for you? Our team is ready to help you understand if they’re applicable for your project, and if so, how you can best approach the project and make sure everyone is on board. 

Mineral Wool Insulation for Safety, Sustainability, Sound, & Sanity!

Sometimes homes are built in places with noises we can’t control. Whether it’s a plane overhead, a train nearby, or a loud neighbor who likes to sing off-pitch. If you find that there are noises you’d like to keep in, or out, from your sanctuary of a home, the insulation you use is quite important. The cotton-candy looking stuff simply won’t do. You need something more durable, more sustainable, more sound-blocking, and all around so much more. 

When people are looking for increased sound barriers, more sustainable temperature control, safer materials from rot and fire, they typically turn to mineral wool insulation. And, we can see why! Let’s take a quick look at why this stuff is so amazing!

Mineral Wool Insulation is considered ideal for a number of reasons: 

Fire Resistance

Mineral wool is a winner for so many situations because it has a melting point of 2150 degrees F. Compare that with the average range of house fires of 1200-1400 degrees F. You realize quickly that the material simply doesn’t catch fire in an average residential fire, and as a result, it doesn’t allow fire to spread. Mineral wool is ideal as well because when heated, it doesn’t release toxic gases.  

Rot Resistance

Mineral wool insulation is an ideal material in areas typically prone to rot. Mineral wool insulation is permeable, which allows vapor to pass through, which is extremely helpful in Vapor Open Air Tight design. It also has no food source, so mildew, mold, and bacteria have no interest in setting up shop around this material. If concerns for mold or allergies are paramount, then mineral wool is a material you want to consider. 

Sound Dampening

Mineral wool has been a go-to insulation when you need quality acoustical barriers. Mineral wool is denser than conventional insulation, making it ideal for minimizing and absorbing sound. Environments that require better acoustical barriers, like concert halls, theaters, and classrooms, employ mineral wool. In a home, it can be a great asset for those that simply want a quieter home. 


Mineral wool insulation is a very versatile product that allows application in many different situations. There are many ways to detail around windows and doors to include thermal buck, frame extensions, sill extensions, all while using mineral wool to reduce thermal bridging. (Learn more about continuous insulation and how mineral woold can support this technique.) Plus, mineral wool is the perfect addition for renovating with a continuous insulation approach.


Mineral wool insulation has a history of longevity, with minimal shrinkage, crumbling, or changing shape even with major temperature changes. It requires very minimal maintenance and rarely needs to be replaced. The natural properties of the mineral wool consistency provide excellent thermal protection from extreme climates (both warm and cool). This makes for a more comfortable home AND a more comfortable energy bill!

Mineral wool is clearly a great choice for so many applications. Whether the main concern is safety, sound, sustainability, or some combination of these, mineral wool insulation can be helpful for both commercial AND residential projects. Yes, there are other options for continuous insulation in a project, but we’ve found that when building for the long term, nothing beats mineral wool insulation. 

At AE Building Systems, we work with mineral wool on many types of projects, especially ones that are working to be Passive House designs. We carry quality products for mineral wool insulation, including Rockwool Comfortboard 80 and Rockwool Comfortboard 110. Rockwool has been a great partner to the construction community for years and our AE Building Systems team is always here to help answer your questions about material choices and specific products. 

Simple Approach to Improving Ventilation in Any Home

Take My Breath Away… While the Berlin song from Top Gun was a big hit in the 1980’s, in a home, we know that good air quality is vital to a healthy space. As homes have become more energy-efficient and airtight, air quality in a home is one of the top priorities. 

Why Does Air Ventilation Matter in a Home?  

Proper ventilation is like lungs in a body. Homes need proper ventilation to keep air fresh and the indoor space as healthy as possible. Opening windows doesn’t always work because the air that we allow in is not filtered, and we’re losing thermal energy we paid for with our heating and air conditioning bills. Mechanical ventilation is vital to ensure that fresh air comes in and dirty air goes back out. The air inside of a home can build up pollutants, dust, odors, moisture and more, making it a problem for anyone with asthma, lung problems, allergies, or those susceptible to disease. The proper mechanical ventilation design will help ensure that indoor spaces stay safe and healthy from day one. 

How do you ensure that your mechanical ventilation is set up properly?  

Have a plan. 

Most new construction home projects will have a mechanical design in place that should address many of these concerns. Make sure you are working with an expert who is well-versed in air quality and ventilation. Many contractors know the basics, but ask questions to find out if your hired expert has experience with strict air quality standards, and balanced systems, meaning it exhausts the same amount of air that is being brought in so the home is not artificially inflated or deflated (pressurized or depressurized) If you aren’t sure who to talk to, reach out to our team at AE Building Systems. We have a list of trusted pros.. 

Look for a ventilation plan that incorporates air quality measurements. 

There are simpler models that are intended to just run in the background day and night no matter if the occupants are home or away, which is a ‘good’ approach that works for many families. This system still requires spot exhaust fans in the bathrooms and kitchen vent hoods that are manually activated when needed.

A ‘better’ ventilation system selectively exhausts the stale air and odors from the bathrooms and the kitchen, and delivers fresh air to the bedrooms and living areas. This distribution system is a bit more involved, but it can be designed to meet code requirements for bathroom ventilation so that spot ventilation fans are eliminated, and a kitchen vent hood would only be needed with a gas range or if the occupants’ cooking involves above-average smoke and odors. This ‘better’ system requires a higher-end ERV with a boost feature that allows increasing the air exchange rate on demand, for instance when someone is using the bathroom.

By far the ‘best’ ventilation system on the market today employs an ERV that measures the air quality in the home and adjusts its mode of operation accordingly. This unit is called the Conditioning Energy Recovery Ventilator 2 (CERV2) and it is manufactured by Build Equinox in Illinois. Its air quality sensors measure carbon dioxide (CO₂) and volatile organic compounds (VOC) which together offer indications of how contaminated and or spent the air in a home is at a given moment. It uses this information to adjust its mode of operation from fresh air ventilation to filtered air recirculation and sometimes it simply shuts its blowers off to save energy. 

Instead of the passive heat exchanger core most ERV units use, the CERV2 is equipped with a small internal heatpump that allows precise control of the flow and amount of thermal energy that is recovered. 

Here are some of the features we love about the CERV2:

  1. Instead of the passive heat exchanger core most ERV units use, the CERV2 is equipped with a small internal heatpump that allows precise control of the flow and amount of thermal energy that is recovered.
  2. Fan selection size – You can get 6” or 8” and while 6” fans are generally used in smaller multifamily projects, 8” fans are generally used in most single-family residences greater than 2,000 ft² and homes where the elevation is 5,000 ft.   Please contact us to help with design considerations.  
  3. With a properly laid out distribution system, the fully automated CERV2 provides fresh filtered air to the living areas and bedrooms of the home, and dependably removes stale air and odors from the bathrooms and kitchen. Such a system can meet the requirements of building code and eliminates the need for bathroom fans. In some municipalities, a kitchen vent hood is then only needed with a gas range or if the occupant’s cooking involves above-average smoke and odors. Please refer to your local building code. 
  4. Remote wireless booster switches are used for manual activation of high air exchange (boost) mode, or wireless active circuit transmitters that are installed in bathroom lights for automatic activation of boost mode. By temporarily ramping up the fan speed and switching to air exchange mode when someone is using the bathroom, odors are removed more rapidly.
  5. Geoboost provides pre-conditioning in both summer and winter and it can also help with post-heat with a hot water connection.  
  6. The Warmflo duct heater can also be included for additional BTUs in the supply lines. 
  7. The CERV2 uses various configurations for remote sensors and zone dampers, wireless connections, and even an I/O expansion board for more control. Let us know how we might help with your needs. 

Hans Joachim Preiss and his firm BrightSense have been designing ventilation systems for several years. Starting with generic ERV and HRV units, the first generation CERV, and now the CERV2. “The idea of knowing the quality of the air you’re breathing inside your home and having a ventilation unit that constantly adjusts its mode of operation so that a high level of air quality is maintained without wasting energy, is only offered by the CERV2 from Build Equinox. This concept is so simple yet advanced, I have not had a single client who regrets their decision to go with the CERV.” says Hans.

Conceptual simplified CERV2 system:

Sample CERV2 supply and exhaust diffuser locations and airflow volumes:

Sample layout of a CERV2 distribution system:

Learn more about CERV2 and get more product specifications HERE.

Learn What You Can

Whether you are a homeowner, the designer, a contractor, or a specialist on the project, the best thing you can do is to learn as much as possible about the plan for air quality in the home. Here are a few simple ways to educate yourself:

Your home should be a safe, healthy space. That starts with strategic mechanical ventilation that measures the air quality. When you are able to monitor the quality, you are able to work on any improvements. At AE Building Systems, we want to help you build safe, healthy spaces for yourself or your clients. Let us know how we can help you succeed on your next project!

Passive House Resource Guide

Resource guide to up your Passive House knowledge – 

Whether you are building your own home, or you are hiring a contractor to help build your Passive House, you’ll want to get knowledgeable. The exciting thing about Passive House is that the designs are constantly evolving and getting better. There are new faces joining the movement everyday, and there’s so much to learn!

Educated Consumer

Many homeowners find that base knowledge is vital to the success of their project, especially when it comes to Passive House construction. The more educated you are, the better you can make sure your home is being constructed in the right way. Because of the lack of general knowledge in the industry, it is sometimes best to participate more or less as a quality control agent of sorts. Knowledge also gives you a base for asking the right questions to your contractor. Even more, when you know the details about your type of construction, you can advocate for specific design choices or construction techniques that you might never have considered otherwise. An educated client is a smart client. Your contractor will appreciate the insights you can bring, and you will be more satisfied with the final product.

Educated Contractor

If you are a contractor considering getting into Passive House construction, this is a no-brainer! Education in a focused niche of construction like Passive House techniques is a huge asset to your scope of work. You’ll  find yourself employing passive house concepts or approaches to any type of construction, even if the project doesn’t require strict Passive House requirements. Additionally, if you are certified, it becomes a huge selling factor for people looking for experts  that can achieve nearly any high performance building objective. You can set yourself above the rest of the pack simply by getting more education. 

If you’re looking to up your Passive House knowledge, where do you start? 

Our team has compiled a great list of resources to help you get started. Some of these resources have specific programs and even certifications, and some are simply helpful resources to stay up on the latest developments. Either way, we hope you find them helpful as you go deeper into Passive Houses.

Passive House Associations to Check-Out:

  • (CPHT): Courses and accreditation exams for building professionals. 
  • Passive House Institute US:  This organization is based in the United States, but offers a ton of education on their website if you’re starting off. If you want to go deeper, they also offer certifications in Passive House construction. They even offer live events and trainings throughout the year. 
  • Passive House Institute:  The Passive House Institute (PHI) is an independent research institute focused on performance-based energy standards in construction. They offer certifications, in-person trainings, and a wealth of information on their website. 
  • North American Passive House Network (NAPHN):  A building industry leader in education for low-energy, high-performance Passive House design and construction. They offer educational resources throughout the year, but also with their big conference each year. Don’t miss how they are rolling out a virtual element this year. 

Top Resources For Trainings/Events:

  • Emu:  Emu is an accredited Training Provider with the International Passive House Institute (PHI). They are authorized to offer Certified Passive House Tradesperson 
  • Local PHIUS Meetup: Look for Passive House Meetups in your local area. If you’re in Colorado, we’d love to see you at an upcoming event with this Meetup.  
  • NAPHN Conference in New York: Join NAPHN for their annual conference. More info HERE
  • PHIUS Conference:  Currently set for Fall 2020, the PHIUS conference is always full of great speakers and education! Learn more HERE
  • Global Passive House Happy Hour:  The Passive House Accelerator has a weekly virtual happy hour with people from all over the world. You can find out the times and details HERE. They also have a great newsletter you can sign up for as well, full of quality information. 
  • Love | Schack:  Love & Schack are two architects who focus on client-centered design with high performance and natural materials, and made a witty company name when Lindsey and Lindsay joined forces! They offer amazing designs, but also put on webinars and share great resources with their community. 
  • Build Equinox:  Build Equinox is a great source if you love getting into the details of Passive House construction. They regularly put out new articles and updates to help the community stay on the forefront of this industry – especially related to ventilation strategies.. 
  • Certified Passive Home Consultants: If you need someone to weigh in on your project, consider hiring a certified consultant to give you expert insights. See the above sites for certifications to also find certified experts.

To Stay on Top of the Passive House Movement, Consider Following our Favorite Instagram Accounts:

7 Value Engineering Tips for Window and Door Design

Have you or your clients had significant sticker shock when the window and door bids are provided? It is pretty common… but there are ways to reduce cost without sacrificing much and often while improving performance.   By Value Engineering (VE), you’ll help save money with your project and there are several concepts to consider to make it happen.  

Value Engineering is often an untapped resource in projects that can save costs on a project without necessarily compromising quality and often while improving performance. Experts in Value Engineering can help identify opportunities to create a more efficient setup, especially when it comes to windows. Since we, at AE Building Systems, are always concerned about energy efficiency, we are proponents of anything that improves performance first and foremost. 

Considering performance vs. cost savings, in the window world, they often go together.  Whether you’re looking at many window manufacturers or options within the same manufacturer, there are a number of VE options that can actually save you a ton of money, and improve energy efficiency at the same time. The homeowners will pay less at the front end while saving money down the road in energy costs. That’s why we’re big fans of Value Engineering around here. 

Worried you might be spending too much on windows and doors? You might consider some of these options:

  • Consider the location/region: The best way you can design effective opening is to design for the homeowner’s climate zone. The product someone needs in San Francisco (e.g. double, triple or quad-pane) are going to be drastically different than what you would want in Anchorage, Alaska. The best way to think through this is to look at the glass performance and how many panes and what type of gas-fill you’re needing. In Colorado, the front range (climate zone 5) can generally use a different glazing package than some of the colder mountain locations (often climate zones 6 and 7).
  • Note the purpose of the space: What is the opening used for? Windows for a kitchen or bedroom are going to need higher performance compared to that of an unconditioned garage or three-season porch. You can get by with lower performance windows in some spaces. If the garage is conditioned which is often the case in mountain areas of Colorado, this might not apply.
  • Selected fixed units where you can: Any time you have operable windows, you increase costs compared to fixed windows. They’re just more complex than a fixed window and fixed or picture windows also perform better – not only do they perform better thermally, they are tighter – reducing air infiltration. If it’s feasible that the homeowner is never going to open the window – go fixed. On the performance side… sliding or hung windows also open you up to greater air infiltration through the unit over casements, awnings and tilt/turns. Comparing hungs and sliders to fixed or casement units is a night and day difference. If you don’t need an operable unit in the space, opt for the fixed unit and save your money now and in the future. If you need an operable – try to go casement, awning or tilt/turn rather than hung or sliding due to the air infiltration rates. 
  •  Overlooked the materials: The materials your units are made from can make a huge impact. Wood and aluminum are often more costly than vinyl and fiberglass. If wood is the look you need, different species of wood can vary in price. Keep this in mind as you determine what material you really need.
  • Use fewer IGUs if you can: Consider various diagrams of the unit and how many Insulated Glazing Units (IGUs) you really need. In the high-performance arena, frames are a known culprit of energy performance. If you can consolidate windows within an assembly, you’ll get better performance and lower initial cost simply because you have less frame material and less labor.  The second window below is one IGU with simulated divided lights (SDLs) where the first unit below has 6 IGU’s. The price difference on these two units is significant and using 6 IGU’s can more than double the price of a window assembly.  
  • Be mindful of the hardware (generally door hardware): We often think about the framed unit itself, but hardware costs can add up quickly too. Decide if you really need to go fancy with your hardware. If you really need something custom, be willing to pay for it. Otherwise, the standard fixtures can save you greatly! Keep in mind that painted finishes on hardware can often cost much less than metal finishes. Also, custom door hardware can be very expensive. Depending on the look you’re going for, these simple choices can help you save quite a bit! 
  • Mind the threshold as well: Don’t stop at windows; consider how your door design can benefit your budget. With doors, consider that a balcony threshold can be beneficial compared to a traditional swing door with a low-threshold. Adding multi-point locking on doors can be helpful for performance (air-tightness), but often adds costs. Other considerations for doors include a basic one-panel swing vs french vs sliding vs lift-sliding vs bifold and others that all impact the price and the performance in different ways. Don’t forget to chat about both price and performance with your suppliers. Check out this threshold example from our Instagram feed. 

On any project, budget is generally a difficult discussion and an important one. We want our clients to be happy about the investment they’ve made, but we also want to deliver high-performing products for them. Value Engineering is a simple way to make smart decisions to maximize performance while reducing costs. We know that windows and doors are often zones in a home where lots of money is spent and we want to see it spent wisely. If you, or your clients, have specific questions about how they can best maximize their opening design for a more efficient home, our team would love to talk. We’ve seen a lot and would love to help you design a happier, more efficient space.

A Better Way With ThermalBuck

ThermalBuck Basics For Energy Efficiency

“There’s got to be a better way!”  Have you ever thought to yourself? So many of us in the world of construction become miffed when it comes to dealing with the problem spots in construction like window and door openings. No, this isn’t an infomercial, and we aren’t going to incentivize you with a set of knives, but there truly IS a better way to build out windows and openings, and ThermalBuck is a huge part of that. 

What is ThermalBuck?

ThermalBuck is a product designed to enhance the construction of rough openings. It solves varying problems in window installation, especially when working with continuous insulation and/or rainscreens. ThermalBuck extends the mounting point of doors and windows to help create a flush plane. It extends the rough opening for a window or door, but limits a common thermal bridge within the building envelope. ThermalBuck is easy to install and flash and is a true continuous insulation option for builders. 

ThermalBuck is also coated with a waterproof resin and is affixed to a rough opening with an air & water barrier sealant along with nails. It doesn’t warp or shrink with moisture, and also provides extra support to the weight of a window.

Why is ThermalBuck needed?

Traditionally, a wood buck is used to extend the mounting point of a window to create a flush plane. However, wood can shrink, warp, or even rot over time. Wood is also not an ideal insulator, allowing thermal bridging around each opening, whether a window or door. Wood bucks can only do so much, and can lead to other issues for energy efficiency, condensation, and eventual moisture damage. Ultimately, this is a contributing factor to why there can be so many expensive repairs related to window and door damage. Wood bucks are helpful, but only go so far. With the ThermalBuck, we see an innovative approach that actually provides more long-term benefits to the end-user.

How is ThermalBuck beneficial?

Can you build window openings without ThermalBuck? Sure, you can. But, why would you when there’s a better way? The ThermalBuck product is so helpful when it comes to preventing heat and energy loss, that we’ve come to see it as a given around here. Here are just some of the main ways it’s so helpful in energy-efficient construction:

  • Easier to install than traditional wood buck designs (Watch how it installs here)
  • High-performance window installation solution 
  • Verified for Passive House installations
  • Maintains the integrity of the window installation with a dimensionally stable solution
  • Simplifies flashing and adds an additional water/air barrier at the rough opening
  • Available in multiple depths to match the projects needed depths. 
  • One solid piece, compared to multiple pieces of wood in traditional wood buck installs
  • R-value of 4.4 per inch

How Do I Use ThermalBuck?

ThermalBuck is not necessarily something we carry alone. Instead, it’s a product that is paired with our Alpen window orders. We work with so many people who care about high performance and reducing thermal bridging in a project that we see these two products pair together seamlessly. That said, you can get ThermalBuck in depths of 1.0” to 4” depending on your needs, and Alpen currently stocks 2” and 2.5” depths. This allows you to use a quality product and get a premiere result. 

ThermalBuck & Passive House Design

In Passive House design, the focus is on energy efficiency, especially at areas of weakness like openings and corners. That’s why we love the ThermalBuck products because they eliminate so much of the thermal bridging that normally occurs at these openings. While there are various angles on ThermalBuck and how it relates to Passive House design, here’s a more in-depth review of the product in relation to sustainable design. One thing we can all agree on is that ThermalBuck is a better alternative to traditional wood buck designs if you are building for energy efficiency. 

At AE Building Systems, we’re always working to educate our customers so that they can build with the best resources and processes possible. ThermalBuck is just one of these amazing products that make building a Passive House or building with an energy-efficient focus so much easier. Our team works with these products every day, and we’re happy to help answer any questions you have about using ThermalBuck in your next project!

Learn more about thermal bridging and ThermalBuck here.

New Year, New Products from SIGA

You may not have asked for construction products for the holidays this year, but that’s what you got under the Christmas tree! As we start off another great year, we’re all excited about the latest and greatest from SIGA. We know this means even better construction and energy savings in projects to come. These products make for big energy savings, big-budget savings, and even more comfort. 

Why do we carry SIGA? 

SIGA carries a versatile line of products for the construction industry and building envelopes. Their products avoid spray applications and also avoid toxins such as chemical dyers, formaldehyde, solvents, and harmful resins. This family business started in Switzerland in 1965 and is focused on research and development to always push the thermal envelope! SIGA products are also proven products to help with Passive House design and construction. Whether you’re building to these standards, or you just want a more energy-efficient space, SIGA products are a winner!

AE Building Systems has carried SIGA products for years, which is why we’re so excited to share the latest and greatest in their innovative products. 

Here’s an overview of the newest SIGA products:

SIGA Majvest 700 SOB

Ready to seal out the elements in a sleek way? The Majvest 700 SOB is ideal for open facades with gaps up to 50 mm and maximum surface share of 40%. As designers start to add in more and more intricate exteriors with openings and reliefs, the construction behind the pretty face of the wall needs to hold up. The Majvest 700 SOB product allows you to do just that. This product is also UV stable, making it an ideal product for any side of the building and in multiple different climates. 

Click HERE to learn more about this product.

SIGA Wigluv Black

If you are thinking of using the Majvest 700 SOB, you’ll want to consider looking at the Wigluv Black product too. This black single-sided high-performance tape is perfect for sealing facades and membranes, especially where the Majvest 700 is involved. This product was designed to work well together and allow you to get a solid seal across any kind of wall shape. 

SIGA Wigluv Black tape is great for any range of temperatures, and is ideal in areas where there are big swings in temperature throughout the day or year. It can handle it all! The black color makes for a seamless, UV-stable product that holds up to fading and aging. This product also has a low perm rating, making is impermeable to water, yet can diffuse water vapor, eliminating condensation risks. If you’re thinking about building a Passive House, this product is your best friend!

Click HERE to learn more about this product.

SIGA Wigluv

We love Wigluv – so much we’re talking about it again. This one is the white version and it now comes in 12” widths! That’s rulers upon rulers worth of seal-tight goodness any Passive House lover can get excited about. Even if you aren’t a Passive House nerd like we are, if you’re just looking for any level of energy efficiency, the wider Wigluv tape is a big deal! 

Wigluv has a reputation for being an extremely sticky acrylic sealing tape, yet low-profile and versatile. This product has a unique vapor-permeable polyolefin (PO) film, pressure-sensitive glue, and reinforcing mesh, allowing it to bond with difficult substrates and in extreme climates. Now with a wider area of bonding, the seal is even more secure, making it a great product for Passive House design and energy efficiency where thicker wall assemblies are used. 

Click HERE to learn more about this product.

SIGA Fentrim 430 Grey

Attention: Product Name Change!

We all know windows are notorious for energy loss, which is why we are big fans of SIGA’s Fentrim 230 grey adhesive tape. This product was specifically designed for windows and door frames to seal exterior component joints. The adhesive tape is ideal for solid structures and metal structures, but can work with a number of different substrates and applications. If you’ve used the Fentrim F product, you’ll find that this is the new product to look for now. Also, this now has four months of UV exposure and comes in 4”, 6”, or 9” versions. It’s designed to be even more versatile and designed to help make these complicated openings in a building more of a breeze to build, while keeping the breeze out of the construction. 

Click HERE to learn more about this product.

SIGA Fentrim 230 Grey

Attention: Product Name Change!

Previously known as Fentrim IS 2, the Fentrim 430 Grey is a winner for so many of our customers. This adhesive flashing tape is fleece-backed, yet semi-permeable. The polyolefin (PO) material helps resist abrasions to the flashing tape, while allowing it to remain pliable (even in extreme temperatures). It works great with proven adhesion to cured concrete, wood, and metal. It comes pre-folded in 75mm, 100mm, and 150mm versions to fit whatever project you have. 

Click HERE to learn more about this product.

Still have lingering questions about these new SIGA products—let’s talk! We’re always happy to help you find the right product for your next project and understand the differences.

Keep the Arctic Out: An Overview of Passive House Design Solutions

Have you ever experienced a drafty spot in the living room? Perhaps, you have one room that just never stays warm? In our modern days, we’ve come to expect that houses simply are drafty or have cold zones. However, the truth is that we don’t have to settle for Arctic blasts inside our homes. There’s another alternative!

Passive House, or PassivHaus, is a remarkable construction strategy that allows us to build spaces that work for us, providing a naturally regulated system for heating and cooling. One major goal of a passive house plan is to reduce energy consumption required to heat a home, but it has many other positive impacts as well including healthier and quieter spaces, greater durability, and greater comfort for inhabitants. Passive House building focuses mainly on three areas: SuperInsulation, low air infiltration and minimizing thermal bridging. In a passive home, you don’t need to sleep in a parka just because your bed happens to be in a drafty corner! Pack up your parkas; there’s no need for one in a Passive House. 

History of Passive House Building

The Passive House was highly developed in Germany, but has roots in North America as well. Now a global movement, the Passive House movement became an idea after the oil embargo of 1973 in the United States. Americans realized the need to be more self-reliant in energy, and the Lo-Cal house was designed. The Lo-Cal house in 1976 was created to be highly insulated and consumed 60 percent less energy than the standard house at that time. 

In the late 1980’s the movement shifted over to Germany where Wolfgang Feist refined the passive house approacheven more. Dr. Feist eventually designed and built the first PassivHaus in 1991 with an annual heating demand of 15 kilowatt-hours per square meter of living space. Feist also founded the Passivhaus Institute (PHI) and created the Passivhaus performance standard, which is known as the highest standard for energy efficiency even to this day. Heating loads must meet 4.75 kBTU/sf/yr. Most existing and even some new homes are 40 to 70 kBTU/sf/yr. Also, airtightness must be below 0.60 ACH50. Most existing homes are 4.0 to 15.0 ACH50 and even worse. 

Passive House Institute US (PHIUS) and Passivhaus Institute (PHI) are now the two leading organizations that set standards for passive homes in North America and in Europe. PHIUS has certifications available for properties that meet their standards and also has many collaborative partnerships with other organizations to promote better energy efficiency in the construction industry.

Why Invest In Passive House/Haus?

Passive House Buildings have strict standards. While many homes meet all the requirements, some also follow the guidelines but don’t get certified (we call these Darn Good Houses around here and you can see why we coined this phrase here). Many homeowners and designers also work to retrofit existing builds along the passive haus ideas to help lower the energy load on an existing structure. There is also a retrofit standard separate from new construction. Regardless of the type of project and level of certification, there are numerous benefits to a Passive Haus building:

Illustration by Passive House School
  1. Comfort: Passive House Standards are focused on a superior level of comfort both during the cold months AND warm months. The design concepts work for both extremes of climate, including the extreme heat of the desert to the extreme cold climates. Multiple studies by passive home residents confirm these high levels of comfort year-round.
  2. Quality:  Passive House designs are known for high efficiency largely due to the high levels of insulation and airtight design. Any weak spots around the home are constructed to Passive House buildings standards. Special attention is put on the windows, doors, corners, and any other angles.
  3. Sustainability:  Passive House design is sustainable by nature, due to the dramatic energy savings in heating/cooling the home. They use very little primary energy, and any extra measures for building a house in the first place to these high standards pales in comparison to the amount of energy savings the house will have over the lifetime of the building. A Passive House requires as low as 10 percent of the energy used by typical Central European buildings!
  4. Cost Savings:  While Passive House buildings have some extra upfront costs, they truly are an investment, rather than an expense. Any additional budget items in the original build save a homeowner thousands upon thousands in the long run in energy costs. 

Beyond The Residential Home

What began as a way to decrease the loads on residential homes, has now become a global movement for passive design at large. The applications are just as relevant for commercial designs for almost any type of space, from hospitals to schools, to commercial store buildings, offices, and more. The Passive House design principles have been adopted by architects, engineers, and contractors alike to make smarter spaces for our communities. If we can build smarter and more efficient buildings, why wouldn’t we? It’s simply the logical thing to do.

AE Building Solutions is proud to be a leader in the Passive House world, providing building envelope components and products that help designers and contractors meet Passive House Standard and certification requirements. We carry products like windows, weather/air barriers, ventilation systems, and insulation for comprehensive building construction. We’re devoted to increased thermal performance, reduced air infiltration, and reduction of thermal bridging to make more efficient homes. 

Given we are burning through our natural resources rapidly, AE exists to help make a dent. Wanting to have an impact on our children’s energy and environmental future, setting our children up for a better tomorrow, and simply doing things more energy efficiently is all a part of AE’s mission.

Looking to get involved with other Passive House construction professionals?