Tag: energy efficient

Energy-Minded Design: The Balance Between Form & Function

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

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

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

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

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

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

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

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

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

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

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 2Ă—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.

Collins Residence Part II

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

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

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

Biggest Lessons Learned:

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

What’s Still to Come?

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

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

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

Here’s the new video >>

Why Do All This? 

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

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

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

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

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

Todd Collins 720.287.4290

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.

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, Greenbuildingadvisor.com, Thermocore.com

High-Performance Windows

If eyes are the windows of the soul, then windows are the eyes of the energy-efficient home.

Generally, windows are the weak link in the walls of a home. “I love putting plastic on my windows to keep cold air out and warm air in,” said no one ever. That is why considering the brand and style of the windows in a home is just as important as deciding insulation and exterior materials.

The goal is comfort and operational cost saving, and the goal for builders and architects is providing both.

High performance windows are necessary in keeping with Passive Haus standards of efficiency: design, minimal thermal bridging, air tight, super insulated, optimized glazing, energy recovery ventilation and passive gains.

So we have learned that code built homes often lose 20 to 40% of the heat in the home through air infiltration, and windows and doors are a significant source of this heat loss.

To better grasp just how significant, imagine the volume of a basketball as our measure of air infiltration. According to the National Fenestration Ratings Council (NFRC), the maximum allowable air infiltration in a window, with the outside wind at 25 mph, is 0.3 CFM (cubic feet of air)/sq. ft. Air infiltration for a 10 sq. ft. standard window at the allowable maximum is 3.0 CFM or 11.4 basketballs per minute. At sixty minutes, one window allows in 684 basketballs per hour.

If you have (30) 10 sq. ft. windows, that equals 342 basketballs per minute or 20,520 basketballs per hour. That is a substantial amount of heat loss.

How do we reduce the basketballs?

Consider installing Alpen or Advantage Woodwork High-Performance windows. With a high-performance window, air infiltration at a 25 mph wind is <= 0.01 – 0.05 CFM (cubic feet of air). A 10 sq. ft. high performance window is at 0.10 CFM or .38 basketballs per minute or 22.8 basketballs per hour.

Therefore, (30) 10 sq. ft. windows equals 11.4 basketballs per minute or 684 basketballs per hour. We just went from 20,520 to 684 basketballs per hour. To summarize, that’s approximately a 97% reduction of air infiltration from what the NFRC says is acceptable.

The bad news is loss of air through a structure’s windows is like opening the windows and tossing our hard-earned money out of them. The good news is high performance windows fixes that problem.

The overall quality and performance of windows like Alpen or Advantage High-Performance windows is also superior. What makes these windows even more unique are their individual components, designed to combat heat losses (winter) and gains (summer):

  1. Frames – High performance windows have durable, low conductivity frames which generally include insulation. These frames offer better thermal performance. The R-value of most standard frames is r-2 to r-3.5. High performance window frames are r-4 and up to r-7, 8, and 9.
  2. Seals – High performance windows generally have multiple seals, which promote not only weather tight but also air tight seals.
  3. Glazing – IGUs (insulating glass units). Glazing can have double, triple and even quad glass. High performance IGUs have special coatings that high performance window manufacturers leverage to optimize heat gain from the sun in colder months and reduce heat gain and over-heating in the warmer months.
  4. Spacers – Depending on the material used, the spacers in between the IGUs can help increase the interior surface temperature of a window up to 15 degrees. For example, a galvanized steel spacer in a fixed high profile Alpen 525 window is rated R-5.9, whereas a stainless-steel spacer in a fixed high profile Alpen 625 window is R-6.7. Also, high performance window spacers reduce condensation on the edge of the glass (which reduces opportunity for mold and rot) and increases the inside glass surface temperatures, therefore improving comfort.
  5. Gas – There is “gas between the glass,” as it is denser than air and a reliable barrier to heat loss. Argon or Krypton gases are often used. Argon is much less costly, but Krypton increases performance and is often used in Passive House projects.

While ROI (return on investment) is important, comfort and unnecessary energy use are the primary reasons people pursue high performance windows.

High-Performance Windows help create high performance homes which conserve energy for future generations.  We are “burning” through our energy resources (coal and oil) rapidly.  Why not own a comfortable, energy efficient home that is also super quiet and will likely last much longer than your neighbor’s home?   And … let’s conserve our resources for future generations.

Please do not hesitate to call us at 720.287.4290 to learn more.