Energy efficiency is about more than just a yellow sticker on a new appliance. By making a few adjustments to your home, you can save money on your electric bill while reducing your carbon footprint. While it may not practical to install new framing or cover half of your house with earth just to save energy, it is practical to switch out some lightbulbs and caulk around the windows.
Insulation keeps the outdoor temperature from entering your house, reducing heating and cooling needs. A layer of blown-in recycled cellulose insulation in the walls, between the floors and in the attic will prevent the most air transfer (see References 2: Insulation). Most two-story homes have duct work between the floors, but sealing that area to make it a conditioned space can increase the efficiency of the ducts by up to 40 percent (see References 3). When you insulate the attic, be sure to cover both the floor and the ceiling to see the greatest improvement in the second-story temperature. Use an insulation with the optimal R-value for your area. The R-value measures the insulation's ability to resist heat transfer --- the higher the R-value, the less heat will pass through it.
Attic and Roof
If your roof is dark-colored, consider having it painted white to minimize heat absorption. If it's time to replace your roof anyway, consider using reflective roofing materials like specialized paint, sheeting or tile to reflect as much heat as possible. Be sure your ridge vents and attic ventilation fans are in working order to minimize the heat in the attic that can transfer into the upstairs living space (see References 2: Roofs).
Choose energy-efficient windows. See the Energy Star website to determine what type of windows are best for your area. A window's U-value is a measure of how much heat it allows to escape, while the solar heat gain coefficient is the amount of heat it allows in. In general, colder climates should have low U-values and high solar heat gain coefficients to allow solar heat to come in and stay in, while warmer climates require the opposite to keep solar heat out and let hot air escape. Choose a framing material with an insulation ability equal to your windows, and caulk and seal all windows to prevent air leaks. Use awnings in hot weather to allow light in while shielding the window from the sun's heat, or consider planting tall shade trees to block upstairs windows from the sun's path to minimize solar heat gain. (See References 2: Windows)
Remove heavy drapes from your north- and south-facing windows to reap the benefits of even, natural lighting with minimal glare and heat. Consider installing skylights in your upper level to further reduce the need for daytime artificial light. When artificial light is necessary, install dimmers or motion-sensor switches to reduce the energy used by the fixture. Installing compact fluorescent bulbs can save 75 percent of the energy used by incandescent bulbs, and LED bulbs can save up to 80 percent (see References 1). Both will cut down on heat emitted by lighting fixtures, saving on cooling costs.
Angela Brady has been writing since 1997. Currently transitioning to a research career in oncolytic virology, she has won awards for her work related to genomics, proteomics, and biotechnology. She is also an authority on sustainable design, having studied, practiced and written extensively on the subject.