Author: Shawn Teasley

Passive House Wins: Top High-Performance Trends of 2024

As 2024 winds down, we’ve been reflecting on a great year—and, true to form, diving into the data! We analyzed this year’s blog posts to uncover the “hottest high-performance topics of 2024.”

The big trend we discovered is that readers are eager to learn how to conserve energy, improve thermal performance, and cut costs at home. Innovations in window technology and reducing reliance on natural gas sparked particular interest, signaling that 2025 could be a great year for increased awareness of Passive House principles.

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

Todd Collins and his family have been on a multi-phase journey to retrofit their home in Golden, Colorado, aiming to get as close to net zero as possible—all while maintaining a comfortable living environment.

In this article, we explored the latest step in their sustainability journey: replacing their water heater and furnace and capping their gas line. We dive into the details of their new water heater, what drove their decisions, how they approached the upgrade, and whether it’s delivering the results they hoped for.

Todd practices what he preaches about embracing Passive House principles, and his family’s decision to make this change came down to several key factors:

  • Achieve their goal of net zero energy and reduce fossil fuel use
  • Eliminate environmental and safety risks (no gas = no carbon monoxide danger)
  • Lower utility costs by relying more on solar power
  • Taking advantage of timing, as the old water heater was due for replacement
  • Relocate the water heater to a more efficient spot in the home for better thermal performance.

The result was a resounding success! Their family of four, including two teenagers, has seamlessly transitioned to the new system. This upgrade has improved their home’s energy efficiency while enhancing their quality of life and peace of mind.Curious about the products Todd used and how he made it all happen? Check out the full story of how the Collins-Ruddy residence capped their gas line and took another step toward sustainability.

2. Alpen Climbing Higher With Two Big Announcements

This year, Alpen High Performance Products made headlines with two major announcements: a $5.8 million grant from the U.S. Department of Energy (DOE) and the appointment of Andrew Zech as their new CEO. These milestones mark an exciting period of growth and innovation for the company.

Here’s what these updates mean for Alpen:

  • Well-earned recognition for their dedication to designing high-performance windows and doors that enhance energy efficiency and sustainability.
  • Creation of over 100 new jobs thanks to DOE funding
  • Expansion with a new manufacturing facility in Vandergrift, PA
  • A projected tenfold increase in production capacity to meet the growing demand for products that improve thermal performance.

AE has proudly worked with Alpen for over a decade, and we’re thrilled to see their continued success. Read more about Alpen’s success and AE’s collaborations with the window manufacturer.

3. High-Performing Windows for High-Performing Homes

Rounding out our top three blog posts of 2024, Alpen High Performance Products continues to rack up accolades—and the results mean even more savings for consumers.

This year, Alpen’s Zenith line of high-performance windows earned a spot on EnergyStar’s prestigious “Most Efficient” rating scale. While Passiv Haus standards are even more rigorous, this recognition highlights Alpen’s commitment to sustainability and efficiency. Their windows also featured prominently in multiple award-winning projects showcased at the PHIUS Passive House Conference.

What this means for consumers:

  • Up to $600 in federal tax credits for qualifying windows and doors through 2032
  • EnergyStar upgrade assistance options
  • High-performance products that deliver real energy savings

Want to learn how Alpen products can help you save money and energy? Get all the details here.

We’re excited to see what our readers are eager to explore in the year ahead. Don’t miss a single update on Passiv Haus and high-performance construction—subscribe to our newsletter and start 2025 informed and inspired.

Wishing a Happy New Year to all our clients, colleagues, and friends in the industry!

2023’s Top-Tier Trends: High-Performance Insights Reshaping Construction Practices

A brief overview of the high-performance principles explored in 2023 reveals intriguing insights.

As we approach the year’s end, our data-driven curiosity led us to analyze the most resonant topics from AE blog posts. After scrutinizing our performance stats, we’ve identified the standout themes as the “hottest high-performance topics from 2023.”

What stands out from this analysis is a notable interest in comprehending the intricacies of the building envelope and airtightness. It underscores the significance of energy-efficient windows within the broader project context and the increased desire to prevent energy loss, resulting in a growing consciousness regarding Passive House Practices.

1. Passion for Sustainability at the Poindexter House

Combine a little bit of personality and A LOT of passion for sustainability, and you get an amazing home! The Poindexter/Kavan Project is living proof of this, and we’re thrilled to be a small part of this home’s story. 

This blog interviewed Amanda and CJ and dug into the mission behind their personal build called the Yeti Cooler House. They 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!

We think it’s safe to say they are a “power couple” with a passion for building in lasting and energy-efficient ways; they walked us through the following considerations for the build.

  • All-electric
  • Sustainability
  • House orientation
  • Overall simple design they chose
  • Vented Roof Assembly
  • Wall Design
  • Window selection
  • Ventilation
  • Mech
  • Air-sealing and its importance

Read the complete story and products selected for the Yeti House.

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

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

In this blog, we detailed window differences: how European windows and American windows vary.

  • Materials in windows
  • Installation of windows
  • Opening and closing: in or out
  • Focus on efficiency
  • Sash clearance
  • Frame/jambs
  • Balcony doors
  • Sliding doors

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 of building a house with Passivhaus principles! 

Don’t miss the trends we’re seeing changing, and understanding the differences that help contractors and homeowners make the right decisions.

3. Energy-Minded Design: The Balance Between Form & Function

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

To focus on energy-minded strategies, we wrote about:

  • Complex design attributes
  • Common culprits of design “features”
  • Conditioned breezeways
  • Poor orientation
  • How simple is better
  • Materials matter
  • Purposeful corners
  • Exterior living spaces

This floor plan is for a house that has not been built yet. Every corner is an energy penalty—corners are more difficult to air seal and generally include thermal bridging.

Bump-outs, cantilevered floors, dormers, and knee walls are some common culprits. Often, these are poorly insulated and add extra exterior wall surface area and seams in a wall or roof construction. These factors lead to energy losses due to air infiltration and thermal bridges.

Are we saying your house needs to look boring to be energy-efficient? Absolutely not! Some of the most efficient, sustainable homes we’ve encountered are true works of art. However, an energy-efficient home doesn’t happen by accident—read the full article.

At AE Building Systems, our monthly newsletter is packed with invaluable insights on Passive House and high-performance construction. Have you subscribed yet? 

We wish all our clients, colleagues, and industry friends a fantastic New Year. 

Hottest High-Performance Topics from 2022

A quick reflection on high-performance principles discussed in 2022

As we wind down the year, the data nerds in us wanted to see which AE blog post topics resonated most in 2022. After reviewing our performance stats, here’s what we discovered and are now labeling “hottest high-performance topics from 2022.” 

Here’s what this tells us, there is an appetite for understanding the building envelope and airtightness, energy-efficient windows are important to the overall project, and there is an increased awareness for Passive House Practices.

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

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

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

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

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

While it feels counterintuitive, going for the high-performing windows actually moves the needle further than beefing up insulation in the wall itself. Read more about how we debunk the myth and prove the math.

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

2. Anatomy of a Window: Basics for High-Performance Windows

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

Windows are one of the most important features in a home, especially if you love where you live (like we do here in Colorado)! You want to let the local scenery and the sunshine in, but you also don’t want to sacrifice thermal efficiency. That’s why it’s so important to get the window purchase right when you’re building or upgrading a home.

There are 3 main sections to the overall anatomy of a window:

  • Frames
  • Spacers
  • Glass

While we often focus on the stunning view through the glass—understanding ALL parts of the window is vital for overall performance and ultimately providing better thermal performance for any house. Continue over to the full blog post for more on the anatomy and the most common options for residential window glass.

3. Collins-Ruddy Residence Part I (retrofit)

We explored how our very own Todd Collins retrofitted his home.

The Collins-Ruddy Residence is probably much like your own home: it wasn’t built from scratch with Passive Haus/energy-efficiency in mind. So many homeowners buy a home that meets other needs but often doesn’t tick the box of efficiency. And so, we enter a retrofit situation! 

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

The Collins-Ruddy family keeps the thermostat roughly at 68 degrees F in evenings and mornings, and 60 degrees F at night and when not occupied. Read the full post to see what went into phase one of Todd’s energy retrofit.

Get a tour of Todd’s house and progress in this video.

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 our clients, colleagues and industry friends a wonderful New Year; see you in 2023.

Hottest High-Performance Topics from 2021

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.

Thermal Bridging and Issues with Windows

As a homeowner, heat loss is or should be a big concern. Energy escaping through the building envelope (walls, roof, floor) means more energy is required to maintain a consistent temperature or better said – comfort -within your home. It also means higher utility bills whether you’re building a new home or looking to refurbish an existing home. One of the most significant considerations should be how to make your home more comfortable but also more energy-efficient – less costly to operate. Which leads us to the topic of Thermal Bridging!

What is thermal bridging?

In a heating climate and similar to air infiltration, thermal bridging results in heat loss and occurs when heat escapes from the inside of the building to the outside, via conduction and through the building envelope. If you’ve ever been in a house that has a “drafty” spot or just constantly feels cold, that’s likely the result of thermal bridging as much as or even more than air infiltration. Even airtight homes can have a heat-losses of 20 to 50 percent due to thermal bridges.

Types of Thermal Bridges

There are several types of thermal bridges that designers, builders, and homeowners should be aware of and the following are three common types:

  • Repeating or Systematic thermal bridges: A common cause of heat loss are repeating thermal bridges which are predictably found inconsistent breaks in the thermal envelope allowing heat to pass through easily. It’s important to keep these in mind during a building’s design. Common Examples include wood and steel studs, steel wall ties, ceiling joists, and insulated suspended floor joists.
  • Non-repeating thermal bridges: This method of heat loss doesn’t follow a pattern in the way that repeating thermal bridges do. A non-repeating thermal bridge tends to pop up in specific areas impacted by an interruption or break in the construction. Common culprits include things that penetrate the thermal envelope to include windows and doors, structural beams, pipes and cables, and cantilevers.
  • Geometrical Thermal bridges: Generally found where the building envelope changes directions and where the materials meet, Geometric thermal bridge examples include wall corners, wall to roof and floor junctions.  The more complex a building design is, the more geometric thermal bridging will be prevalent.

Regardless of the source, avoiding thermal bridges wherever possible is essential – and knowing where your home is losing heat can help you take the proper measures needed to reduce the problem.

Thermal Bridging and Windows

Often, it is windows that are a major culprit when it comes to heat loss and thermal bridging in the home. Standard or code minimum windows often represent a compromise. “We” accept their lower thermal performance because we enjoy the view, natural light, and ventilation they provide. However, when adding high-performance windows with higher R-values (lower U-values), windows become less of a concern for thermal bridging, especially when properly installed.

In an existing home, an expert can determine the state of a home’s windows by doing an inspection. They know what to look for in terms of damage, deterioration, and condition. Knowing a window’s age is a big help as well. Most older windows did not have high-performance glazing nor did manufacturers generally consider thermal bridging in the frames and spacers.

With new construction or existing homes, to reach your energy and comfort goals, it is important to consider high-performance windows. The thermal image below shows the thermal bridging – shown in blue/purple. This is likely why you have seen condensation on windows.

This image below shows the thermal bridging – shown in blue/purple.
The magic of thermal imaging!

Note also high-performance windows help with other variables to include sound attenuation. They reduce the sound coming from the busy street in front of your house for example.

Thermal Bridging Results in Condensation – and Mold

Four variables come into play with condensation: outdoor temperature, indoor temperature, your home’s humidity level, and the indoor surface temperature of an exterior building envelope component. Since outdoor temperatures are not something we have control over, we focus on what is in our control. Windows that have well-insulated frames, multi-panes of gas-filled glass and have higher performance spacers will help increase the interior surface temperature of the windows. Higher interior surface temperatures help to effectively prevent the condensation of moisture on your windows preventing mold from growing. This subsequently improves your air quality. We would be remiss if we didn’t also mention the importance of ventilation systems which improves indoor air quality.

Check out this SIGA Fentrim F for preventing condensation

How To Prevent Window Thermal Bridging

  • Glass: Pursue options that included triple or even quad glazing.
  • Gas: Gas filled glazing is no joke. Argon gas is cost effective and provides a good boost in performance over air-filled units. Krypton gas, while more costly, provides an excellent increase to performance.
  • Frames: Select frames made of low conductive materials. Aluminum frames without thermal breaks are a complete no-no for energy efficiency and comfort. Aluminum is a tremendous conductor of heat. Better options are wood, fiberglass, and PVC with insulating air chambers. These frames are even better if they are insulated. Note, thermally broken aluminum is a good option depending on how good the thermal break is.
  • Spacers: Selecting windows with better spacers can help prevent thermal bridging in the windows as well. These spacers separate the panes of glass and appear where there are divided lights. Avoiding spacers made of aluminum and steel, and selecting stainless steel and various composite materials are much better options. Warm Edge, Super Spacer, and Swiss Spacer are some of the composite spacers that are available.
  • Installation: Proper window installation including air sealing and insulation around the windows will significantly reduce the amount of energy loss. To reduce thermal bridging around windows, Thermal Buck is a great product for the installation.

Final Thoughts

Bringing awareness of thermal bridging to all of your construction partners will aid in your goal. An architect can design to minimize thermal bridges. By not paying attention to the details on the construction site or if there is a lack of training, reaching your goals will be difficult.

If you’re looking for ways to minimize thermal bridges and select high-performance windows for your project, contact us today.

What Are Construction Thermal Bridges in Buildings?

Do you have a random “cold spot” in your dining room or perhaps in an area where a sweater is always needed, no matter how high the thermostat is set?  Thermal bridges may be at play.

If you don’t work in or around construction, you may have never heard the term “thermal bridging”–but you’ve likely felt its effects. In a nutshell, it’s the movement of heat across an object that is more conductive than the materials around it.

Thermal bridging not only causes a loss of heat within the space, it can also cause the warm air inside to cool down. As we approach the coldest season of the year, this means higher utility costs and potentially uncomfortable shifts in temperature inside your home or building.

Keep reading to find out exactly how thermal bridging works and what you can do to stop it:

What is thermal bridging?

When heat attempts to escape a room, it follows the path of least resistance. Likewise, the same process occurs during the summer, only in reverse, allowing heat to enter your otherwise cool building.

Thermal bridging happens when a more conductive material allows an easy pathway for heat flow–usually where there is a break in (or penetration of) the insulation. Some common locations include:

  • The junctions between the wall and the floor, roof, or doors and windows.
  • The junction between the building and the deck or patio
  • Penetrations in the building envelope to include pipes or cables
  • Wood, steel, or concrete envelope components such as foundations, studs, and joists
  • Recessed lighting
  • Window and door frames
  • Areas with gaps in insulation

Impacts and risks assumed due to thermal bridging

What does all of this mean for you? In addition to poor climate control, there are several other lesser-known (but still serious) effects caused by thermal bridging.

Thermal bridges can increase the risk of condensation on internal surfaces, and also cause condensation within the walls.  Both can lead to mold growth, which in turn can cause unpleasant odors, poor air quality, and most importantly long-term health problems. Additionally, unchecked condensation may eventually cause rot and structural damage.

Thermal Bridging in windows

Thermal bridging can have a significant effect on the energy efficiency of windows. The frames and spacers are the primary culprits.  Spacers are the, typically metal, “strip” that goes between and separates the glass on double and triple pane windows.  Different materials have different conductivity and impact the performance of the windows differently.  Condensation on a double pane window is generally due to the spacers.

With retrofit situations, knowing exactly how old a window is, as well as the component materials, can provide you with a general idea of its efficacy. Unfortunately, if your windows are rather dated or just poorly made, it is nearly impossible to add thermal breaks into an existing framing system.

Issues with roofs and foundations

By their very nature, roofs and foundations present a large number of challenges in terms of maintaining a thermal boundary. Drains, vents, and holes for pipes and wires (amongst other things) create unavoidable penetrations in the building envelope and insulation. Heat transfers from the building into the ground or from the building into the air are often inevitable, though they can be minimized.

Strategies and methods to reduce thermal bridges in buildings

Bottom line? In new construction, design it right which a whole topic in itself. With existing homes, if you suspect there is thermal bridging occurring in your space, you need to eliminate or reduce the effects as much as possible.

Proper planning, design, and construction can help remedy thermal bridges in new structures. However, if you live in an older home, there are still steps you could take. These strategies include:

  • Performing an energy audit to identify thermal bridges in your home
  • Installing double or triple pane windows with argon or krypton gas, better spacers and insulated frames
  • Updating and/or adding insulation to your home – ideally adding a continuous insulation layer.
  • Installing storm doors (especially if you have metal doors)
  • The ultimate remedy is to complete a deep energy retrofit that addresses everything and more than mentioned in this blog

Studies show that in an otherwise airtight and insulated home, thermal bridges can account for a heat loss of up to 30%. Whether you’re building a new home or retrofitting an existing structure, care should be taken to avoid unnecessary breaks or penetrations so that the possibility of thermal bridging decreases.

If you’re looking for ways to minimize thermal bridges in your next project or existing home, contact us today.

Dive into our other blogs on thermal bridging:

» Thermal Bridging and Issues with Windows
» Thermal Bridging in Roofs and Framing
» Thermal Bridging in Foundations and Footers
» Thermal Bridging and Decks, Cantilevers, and Balconies