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! 

-Todd

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

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 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! 

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 www.yeticoolerhouse.com.

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! 

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. 

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! 

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. 

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.   

Ducting

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! 

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.

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.

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A quick reflection on high-performance principles discussed in 2021.

Because we are data nerds and love looking at performance (normally energy efficiency), but in this case, we wanted to see which AE blog post topics resonated most in 2021. Below is what Google Analytics told us our top three posts are. 

Here’s what this tells us, there is an increased awareness for Passive House Practices even when building an ADU, people want to invest in a sustainable, lasting home, and the building envelope is getting its due time in the spotlight. This has us quite excited and eager to see what 2022 has in store.

1. 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. Read the full post and see the video tour!

2. 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.” Read the full post and check out the products selected!

3. 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. Read the full post for the top culprits!

The team at AE Building Systems sends out a monthly newsletter with Passive House and high-performance building insights—have you subscribed? We wish all of our clients, colleagues and industry friends a wonderful New Year; see you in 2022.

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:

Homeowners

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. 

Contractors

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!

Partners

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:

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:

• An ERV for bath ventilation instead of bath fans.
• The CERV2 to evacuate bathroom air with booster switches. 

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:

• Use a condensing dryer instead of a traditional vented dryer. Never heard of them? You can get a good explanation of this approach to drying clothes and how it differs from traditional vented dryers here. 
• Install a CERV2 to pull air from a drying closet, making for a more efficiently managed venting system.

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. 

Lights:

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:

• Consider using Studor Vents, or Air Admittance Valves (AAV) 

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! 

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.

Allergies

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!

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.

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!]

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!

Bonus!

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

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. 

Consolidation

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! 

Automation

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.

Showroom

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 info@aebuildingsystems.com.

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. 

Education

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!

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”

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. 

Maintenance

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.

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. 

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. 

Pros:

• 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. 

Cons:  

• 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:  

Pros:

• 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” 

Cons: 

• 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. 

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. 

Versatility

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.

Durability

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. 

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:

• See the basic specifications and product information. Click HERE for CERV2 info. 
• Consider the installation process and understand the product from start to finish of installation. Installation manuals are a great place to start to understand how a product is meant to operate. Take a look. 
• Research the manufacturer of the ventilation system. Go scope out the company directly and see what you can learn from them directly. You can learn more about Build Equinox here. 
• Sign up for Build Equinox’s newsletter. See one of their recent ones here with opt-in options at the bottom. 
• Take a look at CERV-IR’s Magic Box Mechanicals detailed specs. Click here to view. 
• Talk to an AE Building Systems team member to ask general questions. We can help point you in the right direction and help you find the answers you need. 

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!

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:

• @buildingsciencefightclub – Building science and construction for architects
• @emubldgscience – Empowering the construction industry through Passive House training, virtual prototyping, and standardized systems
• @risingerbuild – Builder, remodeler, and YouTuber focusing on high-performance homes
• @passivehouseschool – Source for Passive House knowledge
• @phoenixhausgj – Prefab Passive House designs and manufacturing. 
• @unbuilditpodcast – New industry podcast coming to the scene
• @greenbuildingadvisor – Information about designing, building, and remodeling high-performance homes
• @Passivehouseaccelerator – Insights from the Passive House community to design+build better buildings
• @alpenhpp – Providing high -performance products, windows, and glass
• @thermalbuck.us – High- performance window buck systems 
• @advantagewoodwork – Carpenter focusing on Passive House best practices
• @siga_north_america – SIGA, focusing on zero energy loss buildings
• @passivehouseinstituteus – Profile for PHIUS
• @buildingsciencegirl – Educator of building performance for homes
• @rockwoolna – Smart and sustainable stone wool insulation products for the construction industry.

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.

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:

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? 

• Join us at the Passive House Meetup in the Denver Area
• Join us at Emu’s Colorado Passive House Happy Hour
• Join us at the next JCRES meeting 

In this post, we’ll go over a few key tips for installing windows, sliding doors, and swing doors. Whether you’re updating windows in your home to modernize the look or increase energy efficiency, or you’ve got a new build going up, we hope the information we’re about to drop gives you some insight to the highlights of installation. NOTE: Any window or door you purchase should come with an installation guide, which you’ll want to read thoroughly. If we provide information here that is not in your instructions, please confirm with the manufacturer before proceeding.

While it may seem intimidating, installing a door or window is completely doable for everyone from the DIY-er to the seasoned builder. If you need a refresher on the various types of windows and doors, head back to our last post. Otherwise, grab your ‘driver, level, and some shims – here we go! 

Installing windows

There are many different kinds of windows, but the approach is generally the same. The basic steps are 1) Flash 2) Frame, 3) Install, 4) Seal, and 5) Trim. You’ve got this!

A few rules to live by:

• Do it right the first time.
• Measure, measure, and measure some more.
• If the opening is wider than 3 feet, use temporary supports.
• Moisture is your enemy.

We’ll assume you’ve already done your measuring and have prepped your framing, including checking for any water damage and replacing any wood that’s not up to the task at hand. Better to do it right at this point than to tear out all that hard work later.

Prep and preflash

First things first, prepare your opening by protecting the wood. There are a number of products you can use, but we won’t get into all the options here. Here’s a brief document that shows how to prepare an opening. However, if you’re doing a retrofit and working with replacement windows, getting the situation to look like this is not likely. You’ll just prepare and protect the opening as well as you can. 

Plumb, level, and square

Next, you’ll “dry fit” your window – pop it into place and add a few screws at the top to hold it there temporarily. Grab a couple shims and make sure the window is plumb (level along the jambs), level (from the sill), and square (corners are perfectly 90^०) on both the sash and the frame. 

A trick for measuring plumb: Measure the diagonals of the windows, and if the numbers are equal each way, you’ve arrived at plumb. The longer the level you use, the more accurate you can be.

Don’t put away your level and framing square yet – you’ll be checking and re-checking each piece throughout the whole process.

Nail flanges

Many windows will have a nail or screw flange (also called a fin), that attaches to the window jamb. Not only do they make installation pretty simple, they also do a great job keeping moisture out. While you will hear folks call these nailing flanges, do we really want to swing hammers near our windows? Screws are also a much better fastener for the long run.

You can screw right through these flanges to attach the window frame to the jambs, but first, you’ll need to cut the siding and slip in weather barrier behind the siding, wrapping around the framing for weather protection.

Next, you’ll caulk all around the opening where the flange will attach. Before you tilt the window into place, be sure you have some shims handy so you can shore up level, plumb, and square once again. Then drive your screws through the flange. 

Anchor brackets & through-frame install 

Another option that is increasingly used and very common with Euro windows is anchor bracket install. Generally installed to the interior, anchor brackets are metal strapping that is attached to the window and then fastened with screws into the jamb.  All the usual guidelines – plumb, level and square – apply. Anchor brackets are often used to install windows in thick walls like double stud walls and in high performance situations where we want the window in the middle of the insulation layer. 

Through-frame, sometimes referred to as a block-frame install, is just that – screwing through the frame to fasten the windows. Note that this is more common with operable windows like casements and tilt/turn windows. If using a through-frame approach, make sure you communicate that to your sales representative as special accommodations might be necessary with the windows. Using through-frame is less common with fixed windows as it generally means you have to remove the glazing and then re-glaze after the frame is installed. 

Fastener frequency

Always refer to the manufacturer’s instructions related to frequency of the fasteners. Also, pay special attention to fastener frequency when in high wind-load areas. More fasteners are often necessary where the wind loads are higher.

Interior jamb and sill extensions 

If your jamb turns out to be flush with the drywall inside once you’ve installed the window, lucky you. For the rest of us (especially when retrofitting an older home), jamb extensions may seem like a good option.

A jamb extension is the piece that extends the jamb (the frame of the window) along the inside depth of the wall. Not only does this clean up the window framing, it gives you a clean edge to attach the casing. 

Sill extensions build out the sill area and give you a smooth line, whether you’ve opted for a deep window frame or not. If you’ve chosen not to have a substantial window sill, this may only extend to the edge of the window trim; otherwise, it can be as deep as you’d like it.

Pro tip: We recommend against interior jamb and sill extensions because it limits access to the rough opening gap for insulation and air sealing. If you do go for it, it is often easier to build and install these extensions onsite. Also, we recommend taping the interior all the way around to the jamb to complete the air barrier. Please contact us for more information on this. 

Exterior finishing

On the exterior of the building, you’ll add your exterior casing, fasten that into place, then caulk all the way around. Install your drip cap over the window with some caulking, slipping the top edge just beneath the siding. Secure that drip cap to the top of the window casing.

Inside, fill any gaps between the window jambs and framing elements with loosely packed fiberglass insulation or a window foam. Then you’re on to a final caulk (and ideally tape) on the flange and painting.

Exterior frame extensions and sill are also available, which create a different look but also help to improve the performance of the wall overall. Passive House would say to put the window in the center of the insulation layer to get the best overall wall performance (window and walls collectively). An “innie” install makes things a bit trickier for detailing. Exterior sills and frame extensions help reduce some of the brain damage of these details. Again, please contact us for more information on these options. 

Installing sliding doors

Sliding doors are great. All that added light, plus they don’t require the interior clearspace a traditional swing door needs to swing open. What’s not to love? 

When installing a sliding door, the key pieces to pay attention to are where and how the door meets the floor and getting everything super duper leveled up to keep that sliding action smooth for years to come. If you’re doing your project with us, we’ll talk through all the micro details up front so the installation process is as seamless as possible.

There are a couple options related to the floor detail, and specifically to the threshold. Give us a call to discuss options like FASTrack where the sliding door actually embeds into the concrete floor providing a super clean look. Note that there are thermal bridging considerations related to these types of systems. 

Plumb, level, and square

Just as with your windows, taking the time to get plumb, level, and square straight will save you a host of headaches down the road. Since sliding doors are usually bigger than windows, small degrees add up and can mean your door will sag, stick, or even drift open and closed. 

We’ll add another term to this: “True.” True is your double confirmation: If plumb, level, and square are right on one side but ever so slightly sloppy on the other, you’re not true. Both sides of the door need to be plumb, level, and square to be true.

Installing swing doors

If we haven’t hammered this home enough yet, plumb, level, and square are operative words when it comes to doors, too. When installing a door, shims will start to feel like your right hand. This is most important on the hinge side of the door. One key thing to keep track of is how high off the ground the door hangs – you don’t want your crew arrive to install flooring and find out said flooring is taller than the bottom of the door sash/slab, making the door impossible to open.

Euro doors: The sash condition

It is very important to remember that European doors have very little clearance between the bottom of the sash of the door and the bottom of the threshold – generally less than a half inch. What that means is wood flooring installed after the door at ¾” will prevent an inswing door from opening. Make sure to accommodate the finished floor height relative to the door when selecting and installing doors.  

Brick mould and other trim considerations

Pre-hung exterior doors often have brick mould attached – an additional piece of exterior trim (wood, vinyl, whatever your door frame is made of) designed to cleanly overlay a brick exterior and produce a finished look. It doesn’t matter whether or not you actually have a brick exterior – this is just the name the piece comes with. 

Because brick mould makes it difficult to access the rough opening gap, to insulate and air/weather seal around the doors, we often recommend against using it and instead finish the door trim in the field. 

A quick note on installing Euro balcony doors

Balcony doors are essentially a window installation. What sets a balcony door apart is that you have to lift your feet to step over the bottom of the frame – the threshold is not flush with the floor. Not great for high-traffic areas, but it can save you a few bucks where it counts (more here). Plumb, level, square, weatherproofing, and off you go.

Wrapping it up

We hope you found some answers to your burning questions about installing windows and doors in your building. There’s a lot of information out there, and the specific product you get will come with its own installation guide. We’re here to help point you in the direction of some of the tried-and-true products we recommend (like our windows & doors or weather barriers), and we’re always happy to chat about your project. You can get in touch with us here.

Knock knock.
Who’s there?
Harry.
Harry who?
… Harry up and answer the door so we can talk about that big hole in your building!

There are lots of things we geek out about over here, and gaping spaces in buildings get our full attention. First-world countries have come a long way since the Three Little Pigs style of building, and we’ve learned a few things about thermodynamics. 

If you were to take a gander at the headlines for some of our other blog posts, you might guess (correctly) that we’re a little bit obsessed with thermal performance. Keeping heat in and out – consistently – is a big deal no matter whether we’re talking about a hotel, an office complex, or your own home. Of course, it goes beyond comfort: maintaining temperatures the right way can have a big impact on your wallet.

If you’re putting in the effort (and money) to insulate your home well and mitigate heat loss and thermal bridging, it sure makes a lot of sense to peer into the situation created by your windows and doors. 

Let’s look in to windows first.

Windows

Windows occupy, on average, 20% of wall space. But they’re responsible for more heat transfer per square foot than any other surface in your home. So if you’ve been patting yourself on the back for a job well done with insulation and think you can make sacrifices on the windows, sorry folks – windows are worth the investment.

There needn’t be a battle between letting the light in and settling for a closed-in space. Fortunately, there are some great products out there that let you create both Instagram-worthy spaces and the cost savings of a well-insulated environment.

Here are a few things to ask yourself when shopping for windows:

Let’s fling open the sash, shall we?

US windows vs. European windows

We’ll just get this out of the way first: If you’re new to window shopping, you may be confused by the whole US- vs. Euro-style window thing. In Europe, energy costs a whole lot more, so their windows tend to be extra energy efficient. This is accomplished in many ways, from high-performance frames and glass, to a higher quality and attention to detail. Even the way they open is designed to maximize energy efficiency.

European-style windows are…

American windows are…

Here at AE Building, we’re partial to European-style windows that are made in the USA. 

Types of windows

Functionality and durability should be considered right up there with energy efficiency. That includes the material used, how the window will open, and what you need the window to do for you (let the light in, let air in, or even potentially let people out).

Fixed / Picture Windows

These windows are called fixed because – surprise surprise – they don’t open. If you want light but don’t need airflow, these windows are a simple (and less costly) way to go. Fixed windows usually perform better than operable windows as well, both thermally and in terms of air infiltration.

Tilt and Turn Windows

These dual-functioning windows have hinges both at the bottom (so you can tilt it open at the top) and the side (to swing the window open). They’re more thermally efficient, so they’re popular in Europe, and can be more expensive. Note that the turn/swing function is to the inside and not to the outside like typical US-style casement windows with a crank handle. 

Casement Windows

Casement windows are usually rectangular windows that are tall and narrow. They are hinged on one side of the frame and the other side has a cranking mechanism to open the window for ventilation. They open outward.

Hopper 

Hopper windows have a hinge on the bottom that allows the top edge to tilt or open into the room a few inches. They’re usually opened with a handle at the top of the sash and can be difficult to reach on tall windows.

Awnings

Awning windows are similar to hopper windows, except the hinge is on the top and they open to the outside from the bottom of the sash.

Horizontal sliding windows

Sliding windows slide open on a horizontal track. We generally steer our clients away from sliders and hungs because their air infiltration rates tend to be not as great (due to the open seam around the operable portion of the windows). However, there are times when sliders and hungs are a better choice. Talk to us if you need help deciding!

Single-Hung vs. Double-Hung

Where a double-hung window lets you open both sashes, top and bottom, a single-hung window only opens on the top or bottom. Here again, we try to avoid these due to the air infiltration rates, although hung windows can be advantageous where you don’t want a tilt/turn intruding into your space or a casement window opening out to a deck. There are also historical considerations with hung windows as they were the primary option for operation in older buildings.

A few definitions

NFRC = National Fenestration Rating Council

This independent, third-party certification agency assigns specific energy efficiency measures to complete window system, from frame to glass. (“Fenestration” has to do with windows and doors – if you skipped fifth grade or Shakespeare class, “defenestration” is to be thrown out of a window). 

U-factor / U-value

U-factor measures how well a window prevents heat from moving through the window’s materials – in or out. The lower the U-value, the less heat is lost in winter. These ratings generally fall between 0.20 and 1.20, with the higher rating being, say, a single-glazed window with aluminum frames, while a triple-glazed window might get a rating of 0.20 and even lower depending on the gas that used within the glass unit. These days, you can get quad pane glass which can run even lower – into 0.10 +/- U-values.

Visible Transmittance (VT) 

This one’s simple enough: Visible Transmittance measures how much natural light is able to pass through the window. It’s influenced by the number of panes and glass coatings.

Solar Heat Gain Coefficient (SHGC)

A number between 0 and 1, the SHGC looks at solar radiation transmitted through a window or door. The lower the number, the less solar heat it transmits (= more shading). Some people rely on a center-of-glass or glass-only SHGC, which will give a higher number. Full window values include the frame, which has no solar heat gain. The direction your window faces, whether or not it’s shaded, and your climate zone will drive the optimal SHGC for your windows. For example, in colder climates, you want to collect solar heat on the south elevation of the home and block it on your west elevation to minimize overheating in the summer.

Energy Star Certification

Energy Star® bases its certification on U-factor and SHGC ratings for four different climate zones. Learn more here >

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Doors

Now that we’ve got a handle on windows, let’s cover the next gaping hole in your building. Entry doors, interior doors, wood, steel, vinyl, with glass or without, one lock or many… When it comes to doors, you’ve got options.

US doors vs. European doors

Notes on European doors:

Notes on American doors:

Types of doors

Balcony swing doors 

Balcony doors are a popular choice for accessing exterior living spaces like… balconies (go figure, right?). Because they have a higher threshold, they are generally not used as main entry or in high-traffic doorways.

Standard US-style and Euro-style swing doors with a low threshold

For a quick mental picture of a swing door, recall any old Western movie scene where a man with spurs and chaps bursts through the saloon doors. The in-and-out swing of those doors is what gives these hinged doors their name. Thankfully, we’re looking at much more elegant and airtight solutions these days (for starters: hinges, not springs).

Lift and slide

You’re familiar with sliding doors, and the “lift and slide” door takes things to the next level. The “lift” action here utilizes a system of levers and wheels to lift the door up from its position flush against the floor/seal and move with little friction across an internal track. The lift function lifts the door out of an air seal and slides it open. Lift-slide doors generally seal better than typical US-style sliding doors.

For a closer look, check out our Advantage Classic or Mira lines, available as windows and doors.

Tilt and glide 

Tilt and glide doors slide open, with the added flexibility of tilting open at the top for ventilation. The advantage of this tilt is that it’s secure when tilted – kids stay inside, animals stay outside (or inside), and the door remains locked.

For a closer look, check out our Tyrol Line.

A note on multipoint locking

As the primary point of entry for your building, doors generally have a higher security threshold than windows. Multipoint locks are more common in European doors and usually include a deadbolt, live latch, and several additional locking pins around the door sash.

Wrapping it up

Hopefully this primer has helped clarify some of your questions and given you some ideas about what kind of window or door is best for your unique scenario. We’re proud to provide made in the US, European-style windows and doors that are Passive House certified. We’re here if you have any questions, so don’t hesitate to reach out.

In our next post, we’ll get into installation methods. Stay tuned!

This post is part of a series on thermal bridging.

Warm air rises, so you can imagine roofs are kind of a big deal when it comes to thermal anything. Point of fact, your roofing system’s thermal performance is a major factor in your building’s overall thermal performance. And one sure-fire way to sabotage the whole deal is to ignore thermal bridging – the movement of heat through thermal-conductive materials. 

Roofs top off your building’s thermal boundary or envelope. You may think that an attic provides an adequate barrier and insulating your ceiling is enough, but there are some serious reasons to intentionally address thermal bridging whether you’re smoothing out blueprints or staring down a renovation project. 

Read on to discover how reducing thermal bridges can help you: 

• keep your energy costs from going through the roof (literally)
• avoid extreme temperatures in your attic
• prevent condensation problems
• reduce the potential for ice dams
• ensure the longevity of your roof

The good news: Thermal bridging is avoidable. As with any project, it’s possible to go overboard, so recognize the point of diminishing returns, stop there, and enjoy your energy savings.

Recap: What is thermal bridging?

Thermal bridging is the movement of heat through a material that’s more conductive than the air around it. Failure to mitigate can account for overall heat loss of up to 30% – so it’s not a thermodynamics lesson to be taken lightly. (Brush up on Thermal Bridging 101 here.)

When it’s cold outside, the heat inside your building will make its way through wood as much as three times easier than it will move through insulation (and steel is even happier to move heat). So insulation is a good move. But only part of the solution, because mitigating thermal bridging through structural elements and anything that penetrates your building’s envelope is key to building a more efficient building.

To be clear, improved energy performance and energy savings are great, but addressing thermal bridging means you’ll also get a more comfortable and durable building – both in terms of temperature and because you won’t find yourself dealing with fallout from moisture problems down the road.

In this series, we’ve covered how to navigate thermal bridging when it comes to windows, wandered out to decks, cantilevers, and balconies, and drilled down to foundations and footers. Now let’s take a look up at the roof.

Challenges for roofs

We talk a lot about building envelopes, and the roof is part and parcel. The key principle here: Maintain a continuous thermal boundary to help prevent thermal bridging. But before you forge ahead too enthusiastically, take your pick from this list of challenges to make your design phase more exciting: 

Pre-built challenges

Maybe the previous builders used too much heat-transferring wood to construct the roof joists (or worse, filled awkward spaces with wood). Maybe the angle of the roof slope leaves you gaps and tight spaces that make filling with insulation difficult.

Attic temperature control

In a perfect world, you want your attic to feel as close to outside temps as possible. And because hot air rises, clearly the top-most part of your building presents a special challenge. In cold seasons, you’re focused on keeping the warm air in. In warmer weather, it’s all about moving heat out to keep your interior cool. So there’s a balance to strike between venting and insulation when trying to encourage your attic to cycle heat and moisture up and out.

Venting

We won’t get into venting here to stay focused, but it’s worth a mention: you’ll probably want to consider ridge or gable vents that can quickly dissipate heat and maybe even draw cooler air in from outside.

Condensation

If you’re doing an exceptional job keeping your attic cool in summer, you may end up seeing condensation on the underside of the roof deck due to warmer, moister air outside. Any interior cold spots (think A.C. pipes or vents) can also lead to condensation, moisture damage (mold and mildew) and heat loss. And that moisture buildup can cause damage to your roof deck. In winter, the opposite scenario is relevant, with condensation forming on the underside of the decking. 

Roof perimeters

Air sealing is an important part of building a strong building envelope. When air leakage happens at the roof perimeter, you’ll see issues like frost inside the attic (even snow blown inside), ice damming at the edge of the roof, condensation buildup on the fascia, and metal corrosion. You need airflow to help your attic cycle heat and moisture away.

Ice damming

Winter weather can be relied on for its inconsistency. Snow and sunshine are both hitting your roof from above, with the sun usually doing its job to melt the snow. Whatever the sun doesn’t melt, heat transfer from your warm attic will probably make short work of. Sounds great, right? Except these melt-freeze-melt-freeze cycles can put you in a real pickle when the melted snow has the audacity to re-freeze at the edge of the roof where it’s colder, backs up, and then dams under your roof shingles. Great.

Skylights and other penetrations

Structural elements that penetrate the roof (remember, the roof is part of your building envelope) create a thermal bridge. Chimneys, railings, vents, plumbing stacks, skylights – all potential penetration perpetrators. Yes, skylights generally have poor thermal performance. But are they wonderful? They sure are. Traditional installations tend to forgo thermal breaks in the frame, so significant thermal bridging tends to be common around the perimeter of skylights. There are ways to mitigate energy loss, such as wrapping the framing in insulation and ensuring thermal continuity throughout the skylight support. 

Roof-to-wall transitions

Flashing, blocking, and structural supports all decrease R-value. But sealing the roof-wall connections is critical. Do what you can to select non-conductive flashing materials that will minimize thermal bridges and mitigate the rest with spray foam and other insulation products.

Support framing

Wood framing directly conducts heat and cold. If you’re using steel studs, well, then thermal bridging becomes an even bigger deal. And you’re almost certainly using metal fasteners – maybe even hundreds of them across the entire roof. One solution to the fasteners issue is to use a low-density foam to adhere the insulation, but there’s a better way overall… read on for a straightforward solution to many of these roofing woes.

Mitigation strategies

The roof has one job: Keep the weather outside. But because weather can be crazy (and seems to be getting crazier), tasking the roof with keeping the peace between inside and out can be more challenging than it seems.  There are two approaches to roofing strategy, and it all comes down to whether it makes more sense in your climate to keep your roof warm or cool. 

Warm roof vs. cool roof

Cool roof

A cool roof is:

• Traditional (most existing buildings likely use this approach)
• Vented
• Utilizes insulation placed above the ceiling to maintain temperatures
• Has an advantage for warmer climates because venting allows heat to escape faster

Insulation is placed between and hopefully above the rafters or joists with (sometimes) extra insulation underneath, along the ceiling. Now, if you’re retrofitting an existing building, this could get tricky real fast. You may have to open up the roof from the outside or even underneath by taking down the ceiling to add insulation, and you may lose ceiling height inside the room. Plus, when you’re cutting the insulation to fit in each nook and cranny, you have to be pretty precise to get the coverage right. 

On the upside, a well-insulated, ventilated roof can help to control or prevent condensation and the formation of ice dams by allowing heat to escape through the roof in the winter months.

Warm roof

Instead of insulating between the rafters, the warm-roof approach relies on insulation placed OVER the roof deck. In this case, rigid insulation is simply installed on top of the existing surface. This ensures the entire roof structure is insulated – which lends itself to being more energy efficient. 

A warm roof is:

• Usually not ventilated
• Rigid foam insulation is attached directly over the roof deck
• Heat is contained in the attic space or there is no attic (in the case of vaulted ceilings or low slope roofs)
• Growing in popularity for new builds

With the insulation placed outside, if water or air ducts are run through your attic space, they’ll be less likely affected by extreme temperatures, saving you money on utility costs.

This approach is not terribly difficult to implement when retrofitting an existing building, with one note: By putting insulation over the existing roof level, you will add extra height to your roof that may require reviewing your local code as well as making adjustments to your exterior design details (fascia board, decorative trim, and so on).

Exterior rigid insulation

In keeping with our aim to create an unbroken building envelope, wrapping your building with exterior rigid insulation (warm roof) is the best strategy across the board. Be sure to use materials that are less conductive, like fiberglass, mineral wool, cellulose or high-strength foam – or our favorite, Rockwool. Continuous rigid insulation is so effective that some builders are actually foregoing interior insulation because it’s unnecessary at that point!

But wait, isn’t cavity insulation just easier? You might think so. You could use a dense-pack, blown-in cellulose or fiberglass insulation (preferred over trying to squeeze hand-cut batts into cavities) or a more expensive closed-cell spray foam, but you will inevitably find some tight spaces where it’s tricky at best to get the needed amount of insulation stuffed in – usually where the roof slope approaches the exterior walls. For this, there’s a great solution called the raised-heel truss which we’ll get into in just a minute…

Continuous insulation

Having a continuous insulation layer is critical– especially if you’re using any metal framing. Any supports for the insulation layer should be low-conductive or thermally broken. Sure, the support system is bound to have some negative effect on your R-value, but the overall performance advantages still give continuous insulation an advantage over cavity insulation options.

When you’re installing continuous insulation, your layers should be (from the outside): thermal control, water control, air control, vapor control. This should match up with the layers on the walls of your structure.

Seam taping / Air barriers

Seam tape (Majcoat, Fentrim F, and Wigluv for roofs) prevents air and moisture transfer where your rigid insulation boards join and at corners and joints. This helps to prevent condensation at the seams where air might travel through, bringing moisture with it. Seam tape is often used on foil-backed rigid Polyiso (closed-cell, rigid foam board insulation) which also acts as your WRB (water-resistant barrier). Another option is to make sure your WRB is airtight prior to installing the continuous rigid on the exterior. So many options!

Fascia boards

When baby it’s cold outside, and your attic is nice and cozy (or the A.C. is humming during a hot, humid summer), dew point along the fascia board is a real concern. What’s happening here is that moisture wants to drop out of the air onto a cooler surface – in this case, your fascia board. Continuous exterior insulation will help, but if you’re aiming for a cool roof or want to overprotect your fascia, you can also fill the space between the joists with insulation so it’s continuous through the ceiling to the point behind the fascia. 

To insulate the joist gaps or not to insulate?

If you’re installing rigid exterior insulation, it’s probably overkill to insulate the joist gaps. If you can’t do rigid exterior for any reason, or are going for a cool-roof strategy, then absolutely insulate between the joists. A well-insulated, airtight ceiling (so make sure to add air and vapor barriers, too) will help reduce heat loss into the attic in the winter, and save you money in the summer. You can then add spray foam to enhance the air seal at the perimeter, where the walls meet the roof. 

Raise the roof for raised-heel trusses

Where the roof slopes down to meet the wall there’s usually not enough room to install enough insulation.  We’re talking 4’’ vs. 12’’ from the rest of the roof, and in an area where you’re probably going to lose more energy. So that’s not great. (Yes, if you’re doing rigid continuous exterior insulation you’ll still want to look at adding a little extra insulation to your roof-wall connection.) Here’s a great post from the Energy Vanguard blog (with pictures!) for more on this.

With new construction (or serious retrofits), the solution is to add raised-heel trusses (aka “energy heel trusses” or just “energy trusses”). The raised-heel truss approach adjusts the framing at the edge to add height, effectively raising the roof to give you all the room you need for installing insulation that won’t get compressed in that space. Voila, adequate (if not great) insulation over the exterior walls at the eaves. Bonus: You might solve some wind washing problems (air from outside circulating in your attic) while you’re at it.

R-values

It makes sense that since warm air rises, R-values should be higher for attics and cathedral ceilings vs. what you would need for a wall. Not to mention, energy code requirements for the R-value of roofing insulation are becoming more stringent, often requiring an increased thickness of insulation.

There’s no blanket answer for figuring out your target roof R-value. Start by considering your local climate and ideally use Passive House Modeling. Colder climates might necessitate R-values of 60 and even higher – R-100 is not unheard of for a Passive House. In milder climates, you might get away with more like R-30. 

Compensating for poor design

Obviously, addressing thermal bridging is most effective when tackled at the design phase. But sometimes we don’t have that luxury, and there are solutions that can be applied during construction or renovation. In areas where you’re seeing thermal bridging, closed-cell spray foam or even aerogel products can come to the rescue. While probably not cost-effective compared to eliminating thermal bridging in the design phase, you should also weigh the cost of applying these solutions against simply accepting some minor heat losses. 

“And now that you don’t have to be perfect, you can be good.” (Thanks for the permission, John Steinbeck.)

Wrapping it up

Exterior rigid insulation is a great solution for protecting your building envelope as you design your roof. But, it’s not the only solution — we’re going to cover another popular method, framing with double-stud walls, in a future post. 

Serious about energy efficiency and want to get thermal bridging right on your next project? Talk to us.

Want to learn more about the impact of thermal bridging? Start with this post: What Are Construction Thermal Bridges in Buildings?

This post is part of a series on thermal bridging.

Exposed concrete foundations are notorious for glowing yellow on thermal imaging. All that concrete acts as a highway for heat to leave the building, and should be given as much attention as windows, balconies, and the rest of the building envelope.

Let us join the chorus of builders in emphasizing that it’s not just about heat loss. When you have an uninsulated basement wall or slab, yes, you’ll certainly see lower interior temperatures. But the direct result of a lower interior temperature is not just a cooler space, it’s also an environment where condensation is likely to form. And no one wants a damp, dank, musty environment at the base of their building.

Recap: What is thermal bridging?

Thermal bridging (also called a cold bridge, heat bridge, or thermal bypass) is the movement of heat through a material that’s more conductive than the air around it. Thermal bridging can account for heat loss of up to 30%, so you can imagine the importance of addressing this when constructing your foundation! (Brush up on Thermal Bridging 101 here.)

Which materials act as heat highways, you ask? Steel, concrete, and wood (core construction materials) are prime offenders – and can’t really be avoided when building. But you CAN take into account some design considerations that will minimize thermal bridging, if not stop it in its tracks.

We’ve covered how windows are a prime offender for thermal bridging in your home, and we addressed some design considerations for decks, cantilevers, and balconies. Now, let’s drill down into foundations and footers.

Challenges for foundations

If you’ve ever had a basement, you may have noticed that any musty smell becomes stronger in the summer months. That’s because the warmer, more humid air is coming in contact with cooler surfaces that are below the dewpoint of the air inside (more on dewpoint in a minute). Particularly guilty are rim joists, as they tend to run colder.

In a two-story home, basements can account for 10-30% of the home’s annual heat loss in winter – more for a single-story building. Let’s take a look at what’s happening where.

Heat loss

All the cement, studs, and supports that go into shoring up a foundation are perfectly primed for thermal bridging if you don’t take the necessary steps to insulate and construct appropriately.

You might think, “heat loss, no biggie for a basement.” But it’s not just about reducing energy bills and keeping temps comfortable. As we mentioned, because thermal bridging also moves condensation and wetness along those pathways, enter the potential for expensive damage due to moisture and mold.

Moisture

Let’s do a little refresher on dew point.

When a thermal bridge whisks that heat out, you get cooler interior surfaces (good if you wanted a root cellar, not so good if you’re hoping for a cozy place to hang out). And those cooler interior surfaces invite moisture – the root cause of mold, mildew, and decay. Why? It’s all about dew point, the temperature at which the vapor in the air begins to condense.

To control moisture, it’s more or less a matter of properly insulating your foundation and installing vapor barriers. We’ll get to that in a minute.

Foundation-to-wall transitions

One particular area to keep in mind is where the foundation meets the rest of the house – a particularly problematic area for thermal performance. Foundations of course are still considered part of your building envelope, so wherever the concrete (slab, foundation, or foundation wall) meets the exterior wall will need extra attention because any insulation at those points is generally non-continuous.

Challenges for footers

Footers are typically poured concrete with rebar reinforcement and set just underground. Footers support the foundation and help prevent settling. You may also find yourself constructing a footer for a deck, pergola, wall, or garage.

While heat loss through footers can be reasonably low, if you’re going for Passive House, you’ll still need to address it.

Mitigation strategies

When it comes to thermal bridging, two things are critical to consider when constructing your foundation or footer: Insulation (interior, exterior, midlayer) and permeability (vapor and air barriers). Keep this in mind: Your goal is to keep the interior warmer than the exterior in the winter. However, condensation can also happen in summer when the air can hold more moisture.

Insulation

Foundations, basements, and crawl spaces can be insulated internally, externally, between layers of concrete, or both internally and externally. While exterior insulation is the most effective, interior insulation is more common – but it comes with more moisture problems.

Interior or exterior, you may want to check which materials are recommended for your climate zone, as your insulation needs will depend on temperature and humidity ranges in your region.

Exterior insulation

Let’s cover exterior insulation first.

In a perfect world, the best solution is to wrap the exterior of your entire building envelope with rigid insulation, including the foundation.

For below-grade foundations, select an insulation material that can withstand conditions underground, which means it should hold up to moisture, freezing, and thawing. If your insulation will be in direct contact with the soil, extruded polystyrene (XPS) holds up well and will retain most of its original R-value. However, XPS has some reasonably concerning environmental drawbacks (global warming!). Higher-density, rigid mineral wool board is a more environmentally considerate choice.

Heat loss tends to be greatest at the corners of a building (where more material is in contact with the soil which absorbs more heat away from the walls). So, it helps to overlap the insulation at corners – including recesses for doors and windows.

Bonus: Insulation installed outside the foundation wall, as a wing or straight down vertically, can help prevent or absorb some of the effects of frost heaving (for those of you blissfully in warmer climates, frost heaving is the upward swelling of the soil as it freezes). Contact us if you would like more information on this.

Interior insulation

Interior insulation is designed to protect the interior air in the basement or crawlspace from contact with cold surfaces (the concrete and framing).

At one point or another, you’ve probably stuffed insulation into framing cavities and called it good. It’s easy, it’s cheap… but you’re not stopping thermal bridging through the studs and cold hard concrete floor.

Several options for insulating your stud cavities:

• ROCKWOOL or fiberglass batts. While a touch more costly, ROCKWOOL is our top choice for several reasons (which we’ll likely explore in a blog post down the road).
• Open and closed-cell spray foam insulation. Closed-cell spray foam rings in with a high R-value rating. Note that these spray foams act as a vapor barrier at around 2″ thickness. The downside: This creates an impermeable layer which you’ll want to avoid if you have an impermeable layer on the exterior, too. Open-cell spray foam diffuses moisture and can completely fill cavities. The downside: This creates a lot of waste when trimmed. Also, note also the environmental impacts of urethane foams as well as the duration of the air-sealing of urethane. These are likely for another discussion.
• Flash and batt or flash and fill is a hybrid approach to insulation that combines closed-cell spray foam insulation (to create an air seal) with fiberglass batt (usually, or blown fiberglass, blown cellulose, or sprayed cellulose) insulation.

Whatever you use, aim for an insulation layer with a permeance rating that allows for drying – this will lower the risk of moisture accumulation. (Rule of thumb: The greater the permeance, the greater the drying capability.)

Above-grade foundation insulation

While you’re probably used to seeing exposed concrete meeting the siding, you can imagine this is an undesirable scenario when it comes to thermal bridging.

But the laws of physics are on your side. Simply installing an R-10 insulation from siding to footing can cut heat loss by about 70% (for a heated basement). Applying a protective “board” or coating over the foundation insulation above grade will help protect it from damage due to the trades, sunlight, pests, and … weed whackers. There also are boards and coatings that can be colored and textured so as to add to the building’s visual appeal.

Notes for footers and foundation walls

While many kinds of rigid foam insulation have a good compressive strength higher than most soils, you may still want to consult with a structural engineer to verify the likelihood of “creep” – slow compression of the insulation under the footings. One option that is getting more recognition is foam glass. It can be costly but has great compressive strength.

Insulation on the interiors of any stem walls and a horizontal layer of continuous rigid foam or mineral wool under the slab can help address thermal bridging. A lesser-known option for insulating under the slab is perlite, a naturally occuring, expanded volcanic rock that has similar properties to glass. Contact us to learn more about perlite below slabs.

Retrofitting

If you’re retrofitting a building, focus on insulating the top half or top third and save yourself some digging. Warm air rises!

Vapor & air barriers

Make sure you get a vapor barrier beneath the slab to prevent moisture from rising up through the concrete. A sheet polyethylene will work well for this purpose, as well as a capillary break between the footing and the perimeter of the foundation wall. Then you can use tapes or sealant to seal the basement wall to the slab.

Be very cognizant of the ramifications of using  interior vapor barriers as you’ll want to allow drying. The general idea here is to keep the moisture out (obviously). We talk more about vapor barriers and breathing in this post.

Wrapping it up

Hopefully, this post has helped give you some insight into how to properly address thermal bridging as you construct your foundation or building footers. Now that you know what to look for, you won’t be able to un-see all the uninsulated concrete poking up around your neighborhood!

Serious about energy efficiency and want to get thermal bridging right on your next project? Talk to us.

Want to learn more about the impact of thermal bridging? Start with this post: What Are Construction Thermal Bridges in Buildings?

This post is part of a series on thermal bridging.

Have you been charged with designing an energy-efficient deck or balcony? Or maybe you’re looking at blueprints with cantilevers that has your gut telling you something’s not quite right. Perhaps you’re a homeowner itching to start a project, but the term “thermal bridging” stopped you in your tracks. Whatever you’re working on, we hope this entry helps clarify what thermal bridging is, why you can’t afford to ignore it, and how to address it appropriately when constructing a deck, balcony, or cantilever.

Recap: What is thermal bridging?

Thermal bridging, quite simply, is the movement of heat through a material that’s more conductive than the air around it. Anytime a thermal-conductive material like steel, concrete, or wood penetrates the building envelope, it creates a highway for heat to exit (or enter) the building. Don’t think it’s worth taking seriously? Consider that this can account for heat loss at a rate of up to 30%! (Want to learn more? Read our 101 here.)

The inefficiencies created by thermal bridging not only reflect poor design, but can result in high energy bills and discomfort for the homeowner. Worse, because these materials move condensation and wetness along with temperature differences, thermal bridging introduces the potential for expensive damage due to moisture and mold. Just think about the havoc persistent moisture within your walls could wreck!

We’ve already covered how windows are a prime offender for thermal bridging in your home. Now, let’s talk about what you need to take into consideration when building a deck or balcony and incorporating cantilevers into your design.

Thermal bridging in action

Thermal bridging is most pronounced with materials like steel (you’re probably thinking of beams and support, but fastening items are guilty too), although wood will also transfer heat. Basically, if you’re designing or constructing any element that projects from or enters the building, you need to pay attention to our points below in order to get energy efficiency right.

A cantilevered steel deck or balcony might as well be a case study for how thermal bridging works. Or, for that matter, a concrete slab (just look at multi-level apartment buildings). Decks and cantilevered design elements project out from their origins within the building, breaking through the building envelope and really quite efficiently conducting heat from (or into) the building.

Imagine these elements as giant radiator fins and you’ll start to get the picture of exactly how thermal bridging works!

However, with the right strategy and materials, you needn’t drop the trending cantilever look from your design toolbox. Stay with us as we get into some solutions and techniques to help you address this problem elegantly and efficiently.

Risks associated with thermal bridging

Heat leaks

Decks, balconies, cantilevered bump-outs, and concrete slabs are notorious for leaking heat. In the winter, you might notice that the interior floor near a deck feels colder to your feet – that’s poor design helping heat escape through the structure of your home.

Keep in mind this is not just about staying cozy: All of this wasted energy costs a homeowner money and impacts the environment.

Moisture issues

Let’s head back to grade school for a second. Remember what happens when warm air hits a cooler surface? You guessed (or Googled) it: Condensation. Now picture those beautiful decks, cantilevers, and balconies. Not only are they exposed to the elements, but when that warm summertime air travels into the AC-cooled building envelope thanks to thermal bridging, not only is condensation bound to happen, but you could soon have a serious mold problem on your hands. It’s not just a wintertime issue.

Working with a pre-built structure? Here’s how to tell if there’s a moisture problem: If you’re lucky enough not to find mold, you’ll see darkened areas where the moisture has attracted dirt.

One last thing to keep in mind here: having a vapor-open approach to the envelope assemblies is important. If moisture condenses with the envelope assemblies, it has to be able to migrate out of the assemblies or you will have mold issues.

Prevention & mitigation strategies

Ultimately, thermal bridging solutions are all about mitigating heat transfer – but let’s not forget air leaks. Use the following tips and tricks to help you “break the bridge.”

Good design

No surprise, preventing thermal bridging starts with good design. And the best way to get good design from the get-go? Tell your architects and structural engineers to work together and think “energy smart” first. (This may sound easier than it is!)

Ideally, good design doesn’t compromise the building envelope – which means you should try to construct your deck or balcony separately from the building and secure via load-bearing brackets to the walls or support independently. Even better, on its own foundation.

For decks:

So best-case scenario for a deck is an independently constructed structure on its own foundation. Otherwise, anywhere that a deck is attached to or penetrates the structure of the building, anticipate thermal bridging to occur. And if heat transfer is happening, you better believe moisture transfer is happening too.

You need a plan to keep air out of your walls, since air (or more precisely, the vapor in the air) is the primary culprit for moisture condensing within the wall assembly. You might consider installing enough continuous rigid exterior insulation so that the dewpoint occurs outside the envelope assemblies. Using a vapor-open approach will help ensure that if your walls do get wet, they can dry.

For balconies:

You might try supporting the outer corners of the balcony with steel rods or cables attached higher up the building – which can add visual appeal to your exterior design. Or, you might support the balcony with wooden brackets affixed to the building’s exterior. You may also be able to support the corners on independent posts, like you would for a deck.

If none of this possible or the design is already set in stone, using the right materials, insulating them, and creating an air barrier can significantly reduce or even eliminate thermal bridging issues. Read on for more about these strategies.

Structural thermal breaks

A thermal break is a material used to block the path of heat transfer. Incorporating structural thermal breaks (like specialized plates, pads, or foam) between a balcony and floor slab can reduce heat transfer by up to 75%. Bonus: This also improves condensation control.

You can purchase manufactured thermally broken balcony connectors from manufacturers such as Schock and Halfen.   

Air sealing & taping

Air sealing is an important step to making sure your building envelope is airtight. Don’t make the mistake of thinking you’ve covered your bases simply by insulating. Air can move around insulation, bringing higher/lower temperatures – and moisture. Since any penetration through the structure breaks the building envelope and creates the potential for airflow, you’ll want to make sure you have a plan for air sealing.

In fact, you should start the air sealing process even before you add any insulation by using a weather barrier system that is also an air barrier. Arguably, adding an interior air barrier can be a belt-and-suspenders approach. Learn about interior air barriers here.  

The Holy Grail here is an airtight, vapor-open building envelope. (There’s even a certification for that. Learn about Passive House.)

Insulation

Exterior insulation is often recommended and should be considered part of that building envelope you want to avoid penetrating. You’ll especially want to insulate around the highly conductive steel studs and structural framing. Here’s one exterior insulation we trust to do the job well.

Continuous rigid exterior insulation is used for wrapping the building structure. Ideally, you are using enough insulation to move the dewpoint out of the structural wall assembly and into the exterior rigid insulation. “Continuous” is the key word here – you want to install it without breaks. If you need to cut out the rigid insulation around penetrations (which would obviously short-circuit your attempts at preventing thermal bridging), taping and spray foam will be your friends.

Double stud construction: With double stud construction, the exterior studs will act as the structure, while the inner studs are used for chases and insulation with a gap between the two. Insulating the gap between the studs provides the thermal break. Decks and balconies can then be bolted to the structural exterior studs. Other cantilevered details like bump-outs are not recommended without an air barrier and a continuous rigid exterior insulation layer.

An educated crew

Ultimately, a well-informed crew (from architects to structural engineers to construction teams) will know what to look for and the steps they can employ to minimize thermal bridging while making the assemblies airtight.

Wrapping it up

We hope this post has helped underscore the importance of addressing thermal bridging and given you some strategies to make your design work. The good news: With these strategies and the right materials, you can significantly lower or eliminate the risk of thermal bridging in your deck, balcony, or cantilever design.

Serious about energy efficiency and want to get thermal bridging right on your next project? Talk to us.

Want to learn more about the impact of thermal bridging? Start with this post: What Are Construction Thermal Bridges in Buildings?