—Frances Stout, Hillsdale, N.J. Tom Silva replies: Any time you insulate, you’re making your home more energy efficient and comfortable, but the gain may not be worth the expense and effort. Here’s what’s involved in this case. And now that your basement is going to be cold in the winter, you’ll also need to insulate any ductwork and hot-water pipes that are below the ceiling, weatherstrip the basement door, and wrap a thick layer of fiberglass around the water-heater tank. In other words, you’re in for a lot of work.

How to Insulate Your Basement

Not only that, research by the U.S. Department of Energy shows that there’s not much to be gained by insulating a basement ceiling. So I suggest you put your time and money into improvements that have a bigger payback, such as adding more insulation in the attic, weatherstripping your windows and doors, sealing cracks, insulating the rim joist, and adding storm windows.