It can damage walls and ceilings, freeze sliding glass doors in their tracks come wintertime, and pose a health threat if mold builds up in vents or closets. Fortunately, this is an issue that can often be tackled along with your drafts. “Moisture moves with air, and when warm moist air hits a cold surface, it condenses,” Torrey says. “The camera, the blower door fan and test smoke can reveal where the source is. Then it’s a matter of seal this, gasket that, insulate that.” Torrey also says to check that the dryer vent is connected and that bathroom fans vent to the outside rather than your attic. If you notice condensation or mildew between window panes, it may be wise to install high-efficiency Energy Star windows, which are rated for condensation resistance on a scale from zero to 100—the higher the rating, the better the resistance. In the end, although a home energy audit can put you back $400, you may recoup that cost in a year. And that doesn’t include the satisfaction of a comfortable house.

WATER