A house can lose a lot of heat (or cool air) through small cracks and openings. The first step to leak-proofing your home is making sure the big wall penetrations ? doors and windows ? seal tightly, with effective weatherstripping. But most houses have dozens of small potential air leaks besides these big ones. How do you find these leaks, and how do you stop them? A brochure provided by Energy Star can help you find?