In the average house, heat is escaping through every leak, draft, and opening—and that’s like throwing money out the window. Good insulation and weatherproofing can make your home run more efficiently, guard it from the elements, and lower those ever-rising heating bills. Popular Mechanics makes the entire process simple, with hundreds of color photographs, diagrams, and illustrations that teach you how to insulate from top to bottom. Find out how to reflect heat from a radiator, seal gaps around doors, double-glaze windows or add weather-stripping, install vapor barriers, ventilate properly, and block out the chill in attics and between rafters. You’ll feel the difference, and see the savings, almost instantly.