Building A High-Performance Home
Did you know the design and construction of your home can affect its overall health and comfort? The key components to a healthy and comfortable home are: airtight, well-insulated buildings with limited thermal bridges, solar orientation and shading, high-performance windows, heat recovery ventilation, electric heating, and materials choice. Each of these contributes to the overall performance of your home. Building a high-performance home has many benefits including:
- Healthier indoor air quality; no natural gas combustion by-products to breathe
- A more comfortable and quieter home
- Increased resistance to future wildfires and smoke damage
- Fewer maintenance concerns
- Energy costs reduced by 10% or more
- Reduced contribution to the climate crisis
Principles of a High-Performance Home
Airtight and well insulated homes are quieter and maintain consistent indoor temperature more easily. Air leakage or air infiltration allows unheated or uncooled air, depending on the season, to enter your home through unwanted or unseen gaps and the air you’ve paid to heat or cool to escape. Airtightness is the degree of air leakage or air infiltration a home has. Airtightness eliminates unpleasant drafts in your home. The basic principles of an airtight home are installing well sealed windows and doors, minimizing penetrations in walls and ceilings, and sealing air movement at joints in framing. Replacing uncontrolled air infiltration with mechanical heat recovery ventilation allows for more fresh air in your home without losing or gaining as much heat as uncontrolled air infiltration. Insulation provides resistance to heat flow allowing a home to better maintain desired indoor temperatures. An insulation material’s effectiveness is determined and measured by its thermal resistance, also known as R-Value. Insulating your home to achieve high R-values can reduce the home’s heating and cooling load while also allowing it to be more comfortable. It also dampens the amount of sound from outside that infiltrates a home, making the home quieter. Homes are typically only insulated once in their lifetimes, adding a high degree of insulation will pay dividends for years to come in increased comfort and lower energy costs. When considering insulation and costs, the shape and form factor of your home can have a big impact. The compactness of a building or the ratio of the external surface area and the internal volume of a building, has a considerable influence on the overall energy use. The images below all have the same internal square footage but the second and third images illustrate the effects of designing more complex forms which result in an increased surface area for the same useful floor area. This change to the ratio of external surface area to internal volume requires additional insulation required to maintain the same efficiency. In addition to increasing the insulation required, a building with a more complex form is likely to have a higher proportion of thermal bridges. Thermal bridging happens when a material (or lack thereof) within a wall’s structure that allows a faster than normal rate of heat transfer, like the 2×4 studs in a wall that sit between the insulation. In addition to the shape of your home, strategies like a layer of continuous insulation on the outside of your home can reduce thermal bridging. Source
Designing your home so that the rooms that are used most during the day face south means they will get light and heat from the sun, reducing the need for mechanical heating systems and electrical lighting, making them more pleasant and comfortable. During the summer, appropriate shading can reduce the amount of solar heat gain when the sun is highest in the sky. Designing your roof for southern exposure also maximizes the energy generation capacity of any future rooftop solar.
Windows can make up a significant portion of your building budget but do many jobs: let in natural light and views, bring in fresh breezes, eliminate drafts, insulate. Choosing high-performance windows and the number of windows is a fundamental part of your energy design. Triple pane windows reduce heat loss or gain through the window and increase the surface temperature of the inner pane, which reduces the sensation of cold drafts.
Most conventional homes have no mechanical ventilation besides the bathroom fan and kitchen fans, which are only run intermittently. Without regular outdoor air ventilation, the concentration of pollutants inside the home can easily rise above EPA air quality standards, particularly when using natural gas appliances. Heat recovery ventilation or energy recovery ventilation provides fresh filtered air by passing outgoing and incoming air through a heat exchanger which brings the fresh incoming air closer to the temperature of the outgoing air. This efficient and controlled means of providing fresh air to a home allows you to control increase the amount of fresh air coming into a home or shut it off entirely if there is smoke or a bad air quality day. You can’t do either of those things with uncontrolled air infiltration.
Learn the differences between Heat Recovery Ventilators (HRVs) vs Energy Recovery Ventilators: HRVs vs ERVs
Natural gas (methane gas) appliances leak methane into your home. Burning gas creates harmful pollutants like formaldehyde, nitrogen dioxide, acetaldehyde, and ultrafine particles in the home, and according to several studies, leads to a higher risk of asthma vs. an all-electric home. Burning gas for heating also creates risks from carbon monoxide poisoning and gas explosions. All-electric homes with induction/electric ranges and efficient electric heating and heat pump hot water heaters offer improved indoor air quality and eliminate the carbon monoxide and other safety risks. A well-designed heat pump system can also lead to better distribution of heating and cooling and improved overall comfort. Similarly, cooking on an induction range is faster, more precise and more efficient than on traditional gas or electric ranges.
Many construction materials and home furnishings contain volatile organic compounds (VOCs). VOCs include a variety of chemicals, some of which may have short- and long-term adverse health effects. Concentrations of many VOCs are consistently higher indoors (up to ten times higher) than outdoors. VOCs are emitted by a wide array of products numbering in the thousands. Choosing construction materials and home furnishings that are low in VOCs and having a heat recovery ventilator to bring in fresh outdoor air can limit your exposure to VOCs in your new home.
The Benefits of Energy Efficient New Construction
Building Electrification Basics
LEVELS OF HOME PERFORMANCE CERTIFICATION
For an updated look at certifications and incentives for high-performance homes please visit the link below. It is arranged by building certification type, increasing performance, comfort, and efficiency from left to rightEEBC and EnergySmart’s Marshall Fire Home Performance Comparison