Residential Buildings

Energy Efficient Homes

Did you know the design and construction of your home can affect its overall health, comfort and operating cost? 

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 induction cooking.

Expand each component section below to learn more.  

Airtight, Well Insulated Buildings with Limited Thermal Bridges

Airtight and well insulated homes are quieter and maintain consistent indoor temperature more easily.  Air leakage or air infiltration allows unheated air to enter your home through unwanted or unseen gaps and the air you’ve paid to heat escape.  Air-tightness is the degree of air leakage or air infiltration a home has.  Air-tightness 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.

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

Solar Orientation and Shading

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 and roof overhang 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.

Heating and Cooling

Heat pump technology used to be limited to southern regions of the country. Over the past 5-10 years, heat pumps have been improved and designed to operate in cold climates. The result is a new product category, cold climate heat pumps, which can now perform well year-round, even in the coldest counties in Colorado.

Heat pumps offer multiple benefits, including: 

Click here for more information on the types of heat pumps and a video on how they work

Heat pumps are more expensive than a traditional gas furnace, but rebates from Mountain Parks Electric and Federal/State tax incentives bring the costs equal or below gas furnaces. 

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. 

High Performance Windows

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 and 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.

Window placement to maximize solar gain in the winter, while minimizing in the summer, is also important. 

Heat/Energy Recovery and Ventilation

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

Water Heating

Although they cost a bit more [before incentives] than standard electric or gas water heaters, heat pump water heaters easily pay for themselves in annual energy cost savings.

Compared to Energy Star gas water heaters, heat pump water heaters are about five times as efficient, with 50% less carbon emissions, and have about the same annual energy costs.

Compared to electric resistance water heaters, Energy Star heat pump water heaters (HPWHs) consume about 1/3 as much energy, reducing your annual energy costs for hot water by 67%.

Compared to Energy Star propane water heaters, HPWHs are about five times as efficient, reduce annual energy costs by 75%, and reduce carbon emissions by 60%.

For more information on heat pump water heaters, click here


The most efficient electric cooking technology is induction, and induction cook-tops deliver better cooking performance than gas, as demonstrated in these videos (Video 1, Video 2).  Induction cooking is faster, easy to control, and safer than cooking with gas or propane. In addition, because the surface does not heat up (only the pans and food), it is very easy and safe to clean up any spills.

Induction cooking works by creating a magnetic field between the cooking pan/pot and the magnetic coils beneath the cooking surface. The magnetic field then heats the content of the cooking pot. 

In order for cookware to perform on induction cooktops, it must contain iron (cast iron or some types of stainless steel) or have a layer of material with magnetic properties. Some stainless steel cookware does not work with induction – for example, if it is a blend of aluminum and stainless steel, or if the nickel content of the stainless steel is too high. However, some manufacturers of cookware are now putting a layer of magnetic material on the bottom of the pan/pot.

To tell if a pot or pan is compatible with your induction stove, hold a magnet to the bottom. If the magnet clings to the underside, the cookware will work on an induction cook-top. If the magnet grabs the pan softly, you may not have good success with it.

For more information on the benefits of induction cooking, click here