Dean Bennett, who owns Dean Bennett Design and Construction, Inc., a design and building firm in Castle Rock, Colo., suggests looking for gaps in the walls of your basement. "It's very common to have these gaps in houses that are more than 15 years old," Bennett says. "Construction techniques did not involve sealing between the sill and foundation very well. Now, they use a layer of foam between the two."
If you live in an older home, Bennett says you can do yourself a favor by doing a "close visual check" for any holes around your basement or foundation. He says filling in the holes could help prevent hot summer air or cold winter air from filtering into your home – not to mention mice and other critters.
Advertisements will tell you to replace your current windows and doors with energy-efficient ones, and maybe you need to. But many home improvement experts will tell you that if there's a draft, it may be adequate to simply weather-strip your doors and windows.
In fact, "the biggest home-energy and money wasters are windows and doors because of the heat they let out and cool air they let in, depending on the season," says Andrea Thomas, Wal-Mart's senior vice president of sustainability.
Typical cost: The can of spray foam insulation to use in your basement runs about $6. As for weather stripping, the price varies, but a 10-foot strip of rubber window weather stripping can be found at many stores for less than $10.
Typical savings: If you weather-strip, Thomas says the average homeowner can save $160 every year in heating and cooling costs.
Decks. Have a wooden deck? Don't forget to put a new coat of stain on it, once every three years, according to Bennett. "It will weatherproof it as well as make it look better," he says.
Typical cost: Deck stain can cost anywhere from $40 to several hundred dollars. Add a couple hundred dollars if you hire a professional to do it. And if you want to replace a deck, Bennett points out that those made of composite materials don't require staining.
Typical savings: A wood deck that is stained regularly can last 20 to 30 years, Bennett says. "If you never do it, you'll shorten the life of your wood deck by 50 percent or more."