How To...
Increase energy efficiency

By Jeanne Huber
Special to The Washington Post
Thursday, June 26, 2008

Q If you have to choose between increased insulation in the walls of your home or new windows, which would you advise as the most likely to result in increased efficiency? This is a very old house with excellent insulation in the ceilings and roof but old and settled insulation in the walls. This is a circa 1890s house measuring approximately 2,000 square feet and has 30 original windows with aluminum storm windows installed in the 1970s.

Shady Side

ABecause new windows cost so much, many other energy-efficiency improvements are usually more cost-effective, says Brandon Farris, policy director for the Maryland Energy Administration.

For example, your house could have large, unseen air leaks around pipes and chimneys and around the framing for a partially finished attic space. Plugging those gaps would cost very little but pay back a lot in energy efficiency.

Adding wall insulation, as you suggest, is another option, though it's easier to do this in walls that have no insulation, rather than some. When wall cavities are empty, installers can blow in insulation through small holes in the interior or exterior. Because your house has some wall insulation, you might need to cut out strips of the drywall or plaster on the interior and pull out the existing insulation first. Otherwise, it might block the new insulation from filling the entire space.

To get a handle on the most cost-effective ways to improve the efficiency of your house, arrange for a home-energy audit. The Maryland Energy Administration, 410-260-7655, can recommend firms that do this. The cost depends partly on the size of the house. For one like yours, it's likely to be about $200.

Also, check out the U.S. Environmental Protection Agency publication "A Do-It-Yourself Guide to Home Sealing and Insulating With Energy Star," which you can download by typing the title into a Web search engine.

Need help? Is there something in your house or apartment that's clogged, cracked, broken or bedeviling? We'd like to help. Send your questions to Jeanne Huber at home@washpost.com.