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

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

Why Cut the Gas to Your House?

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

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

Timing These Heat Pump Upgrades

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

Strategically Shifting the Water Heater Location for Better Performance

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

What Now? 

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

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

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

The Yeti is in the Details: Window Spacers

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

What Role Does a Window Spacer Play?

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

The Weak Link: Window Spacer

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

A Stronger Option: Warm Edge Spacer

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

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

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

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

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

The Fossil Fuel Ban Trend

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

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

The Challenge

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

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

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

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

The Opportunity:

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

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

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

Three Simple Things You Can Do:

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

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

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

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.

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.

High Performance Walls and SIPs

When building an energy efficient home, High Performance wall assemblies are critical components, and can be grouped into a couple of categories: 1. Built on-site advanced wall assemblies and 2. Prefabricated walls, to include SIPs.

Note that this blog post is largely dedicated to Polyurethane SIPs.  

ICFs, Insulated Concrete Forms, are a good option and are manufactured by several companies. Faswall and Nexcem have an interesting woodchip product. There are pros and cons for ICFs, and it is important to understand both.

Advanced Wall Assemblies

The goal is to improve the wall construction of conventional, stick built homes with advanced wall assemblies to include double stud, stagger stud or continuous insulation walls.

Double stud walls consist of two stud-framed walls set up next to each other to form an extra thick thermally broken wall cavity that can be filled with insulation. Because the interior and exterior framing are separated by insulation, thermal bridging is reduced or, ideally, eliminated.

Stagger stud walls use top and bottom plates that are normally 2×6 (5.5”) – 2×12 (11.25″).  Vertical 2 x 4 studs are then staggered alternately on each side of the plates. This is a good option for extra insulation, reduced thermal bridging and sound-proofing of spaces as well.

Another option is standard construction with a Continuous Insulation (CI) layer. In CI, builders add a continuous layer of insulation across the exterior of all structural members to reduce or eliminate thermal bridges, except for fasteners and service openings. Insulation is installed generally on the exterior of the building and is an integral part of the building envelope. Comfortboard 80 is an excellent vapor open product that can be used for a CI approach. Mineral Wool is generally favored, as foam tends to have low perm ratings and generally the desire is for our walls to dry to the outside.  Often folks using a CI approach do not use enough insulation to move the dew point outside of the wall assembly.  It is critical to have a vapor open approach if the dew point falls within the stud cavity.

Prefabricated Walls

Prefabricated walls are built in a factory, transported to the building site and craned into place. Manufacturers of these types of walls include:

Phoenix Haus, which designs and produces open sourced housing templates for walls that save energy, provide better insulation and allow homes to be more efficient with or without solar energy.

Build SMART simplifies the process of building a high-performance, energy-efficient structure with factory-manufactured modular components. Continuously insulated panels come with pre-installed, energy-efficient windows and doors and are delivered to the building site.

SIPs – Structural Insulated Panels. There are several types of SIPs out there. Generally, the difference between SIPs is the insulation.  Most are made with OSB (oriented strand board) skins, but some SIPs have different skins to include metal or MgO (Magnesium Oxide) skins. Most often, the insulation is EPS or Polyurethane.  However, there are some that are made with mineral wool, PolyIso (Polyisocyanurate) or XPS (extruded polystyrene).

Some SIPs are not considered structural (e.g. most metal SIPs), and they might be referred to as Sandwich Insulated Panels.

SIP panels made of EPS, XPS or PolyIso are glued together generally with Polyurethane adhesive. SIPs made with Polyurethane foam are adhered together with the foam itself creating a tremendous bond and a very strong wall panel solution.

Thermocore SIPS are made with polyurethane insulation core with interior and exterior skins of OSB. Panels are precisely and custom manufactured to the architectural drawings. Included in the SIPs are door and window bucks, headers, sub facia and electrical conduit boxes. Also, beam pockets and additional structure like 2x, LVL or steel posts can be built into the panels.

Construction with Thermocore SIPs is quicker than framed homes. The time from foundation to dried-in is significantly reduced. Labor costs are lower, which is ideal in places where available labor is scarce, costly, unreliable or poor quality. Thermocore SIPs are stronger than framed walls, with lower thermal bridging.

Thermocore SIPS often have higher material cost, the electrical requires pre-planning and can be considered less environmentally friendly due to foam, which is a petrochemical product.

The thermal performance values of SIPs and lower labor costs often make up for the initial cost and planning. SIPs help to achieve a more air tight building as well. In the Passive House and Zero Energy industry, where energy efficiency, comfort and clean air are the goals, Thermocore SIPs are an optional building solution.

For more information on SIPS, call us at 720-287-4290.

Sources: U.S. Department of Energy,,