Cost: Between 49 cents per square foot and $1.50 per square foot.
Advantage: Saves on electric bills and means you won't use your furnace or air conditioning as often.
Most homes have little troublesome cracks and holes that let hot and cool air escape. Prime examples: gaps around doors, holes cut through walls for pipes and electrical wiring, and deteriorating window frames.
These tiny, tedious problems can make a big difference in your home's energy efficiency. Unlike home repairs, energy costs are volatile and can skyrocket with the cost of oil. So the more tightly sealed your house, the better off you'll be when you're on a fixed income, says John Barrows, a New York-based builder, consultant and co-author of "The Complete Idiot's Guide to Green Building and Remodeling."
Also, consider the age of your house: If it was built before the 1960s, it probably wasn't well-insulated, says Ben Spofford, a Cleveland-based contractor and owner of Housecalls Home Services. Before the 1960s, energy was cheaper and people weren't much worried about conserving energy.
If your CAPS contractor agrees, spring for insulating your walls, and even parts of your basement and your attic. It can seem extravagant to insulate spaces you don't live in, but doing so will help maintain the temperature in your living area by keeping hot and cool air from escaping.