Why Making Your Home Energy Efficient Matters

Tate Walker is a project manager for the Energy Center of Wisconsin, a nonprofit organization dedicated to improving energy sustainability. He provides program development, energy research, and technology evaluation to commercial and industrial projects. He has an architectural background and is an active member of the mayor’s Green Task Force for the city of Milwaukee. He is also a board member of the Wisconsin Green Building Alliance.

What are the environmental costs of energy waste in U.S. homes?
There are more than 55 million single-family residences in the United States, and they use approximately 36 percent of the energy sold in this country. The average household consumes the equivalent of 1,092 gallons—26 barrels—of oil each year for its heating, cooling and other energy needs.

Extensive use of fossil fuels, which make up 75 percent of the U.S.’s energy production portfolio, has degraded our environment, human health, and land resources. On a macro scale, energy efficiency can reduce emissions that contribute to smog, acid rain, polluted waterways and global warming. Energy-efficient buildings reduce emissions that cause global climate change and pollution.

Can you scale the big picture down to the homeowner’s perspective?
Energy efficiency measures require a hierarchical approach to maximize the financial benefits. First improve the building’s envelope (walls, windows and roof); next improve the efficiency of appliances (furnace, lighting, water heater, air conditioner and refrigerator); and finally address any potential on-site renewable strategies, like solar panels or solar hot water.

The average home uses 800 therms a year of natural gas for heating. Department of Energy standards require gas furnaces to achieve a minimum fuel efficiency of 78 percent, but a high-efficiency furnace can approach 97 percent—a savings of up to 24 percent. By switching to a high-efficiency furnace, you stand to save up to 190 therms a year on heating bills. At $1 per therm, it would take two-and-a-half to five years to pay back the extra cost of the high-efficiency furnace. And if every furnace became 24 percent more efficient, we could expect to conserve more than 10 billion therms of natural gas per year.

What are the health benefits of more energy-efficient homes?
On average, people spend 90 percent of their time indoors. Since contaminants can be two to five times worse inside than outside, indoor air quality should be of high importance. Homes can be more comfortable and less prone to bacteria and mold growth if insulation, air and moisture barriers are installed properly, and heating and cooling systems are properly sized and maintained. Natural ventilation and light have a pronounced effect on our physical and mental well being. A lack of these amenities can contribute to seasonal affective disorder, allergies, asthma, and some types of cancer. Strategies like passive solar design can help reconnect people to the outdoors and their own biorhythms, making energy efficiency just an added benefit.

What are some of your favorite innovations or design ideas for energy efficiency?
One of my favorite innovations is U.S. GreenFiber’s Cocoon cellulose insulation. It’s great for remodels because it’s blown in, minimizing damage to existing walls. In some cathedral ceilings it can totally fill the interstitial cavity, reducing the chance of moisture infiltration and removing the need for air circulation, which costs more and takes longer to install properly. A fiberglass-based wall insulation loses much of its insulating value when it’s compressed around an electrical outlet or switch, but cellulose insulation conforms perfectly to these anomalies, removing air gaps and reducing thermal bridging. Cocoon uses a borate binder to resist mold and mildew, putting it on a similar performance level with standard fiberglass batt insulation, and it has a high percentage of post-consumer recycled content.

What got you interested in green remodeling?
I got interested in environmental design through a professor in college. I liked it because it helped suggest new forms that were not based on design for design’s sake, but were a thoughtful reflection of the site that they occupied. A building’s form and orientation are major factors in its energy use and its environmental impact.