The Anatomy of a High-Performance Home

Windows are typically the weakest insulation point in any wall assembly. However, by using triple pane windows with low-emissivity (Low-E) coatings, the lowered insulation/R-value of a wall of windows can be minimized because those windows consist of three layers of glass with an insulating gas such as argon between each pane. This third pane of glass reduces drafts through improved air-tightness, ensuring that your home stays warm in the winter and cool in the summer. Some window manufacturers also offer insulation injected into their frames to further assist with increasing their insulation values. Various Low-E coatings are also available that assist with either reflecting the suns rays in areas that receive too much summer sun or absorbing those warmer rays on walls. There are two types of Low-E coatings:

Passive Low-E: Designed to minimize heat loss in colder climates by reflecting heat back into the building.
Solar Control Low-E: Designed to filter out the infrared (heat) portion of the light spectrum, reducing heat gain in warmer climates

Upgrading the amount of insulation around the entire building envelope helps reduce energy demands and increase comfort. There are a lot of different strategies to create a super insulated building, but one of the best is "exterior continuous insulation" (ECI) because it also helps reduce thermal bridging. Other strategies include using materials such as "structural insulated panels" (SIPs), hemp insulation, spray foam, rigid foam, or advanced fiberglass eco-batts to create an airtight envelope.

A typical exterior wall in a home today only has insulation between the wood studs. The problem with this strategy is there's no thermal protection between the outside and inside of a stud. This creates a "thermal bridge" which allows thermal energy to move through the wood stud and thereby into and out of the home, depending on the season. The solution is to introduce a thermal break to slow down the heat loss through the studs and better insulate the building. This can be accomplished via various insulation and framing methods and by addressing these weak points with proper insulation and construction techniques, homeowners can reduce their energy consumption and increase overall comfort.

Airtight construction is a fundamental principle of high-performance homes. These homes are built with meticulous attention to detail in order to make the building envelope extremely air-tight to prevent infiltration or loss of conditioned air. By preventing air leakage, the home is able to maintain stable indoor temperatures and reduce the workload on heating and cooling systems, leading to significant energy savings, performance, and comfort.

In the past, homes were so leaky from an air-tightness perspective - so much so that it was not necessary to mechanically bring fresh air into the home. As modern construction becomes more air-tight it becomes increasingly important to both bring in fresh air and exhaust stale air, allergens, and pollutants, keeping the air pressure in the home balanced. 

To maintain excellent indoor air quality, high-performance homes incorporate a energy recovery ventilator (ERV), which pre-conditions the incoming outdoor air with the energy of the outgoing stale air. Balanced ventilation systems not only support a healthy living environment but also help save energy by reducing the need for mechanical heating and cooling.

High-performance homes feature upgraded mechanical systems designed for energy efficiency and optimal performance. A high performance mechanical system is one that can deliver above average comfort and energy efficiency. Zoning, sizing, and layout all need to be thought through to provide efficient comfort.

One of the best ways of increasing energy efficiency today is by using heat pump technology, whether it's an air-source heat pump that sits outside your home and exchanges thermal energy with the outdoor air or a geothermal ground-source pump that exchanges thermal energy with the earth.

A zero energy home is one that produces as much energy as it consumes. All of the features listed above can help reduce the amount of energy a building consumes, which then reduces the size of a photovoltaic (PV) solar array needed to reach a 100% offset and become truly "net zero". Net-zero homes not only reduce carbon emissions but also save homeowners money on energy bills as seen at the Blackfoot Pass Residence. 

To further enhance sustainability, it’s best to go all-electric even if it means placing a bet on a greener future. By not connecting the home to any fossil fuel sources, homes that go all-electric are fully prepared for the on-going transition to 100% clean energy within the electrical grid. Given the current high cost of electricity, high performance matters even more when building an all-electric home. Adding photovoltaic (PV) solar panels, a geo-thermal heating and cooling system, or exploring energy efficiency incentive programs with your local utility are all great ways of offsetting these higher monthly costs.