A typical family spends about a third of its annual heating and cooling budget—roughly $350—on air that leaks into or out of the house through unintended gaps and cracks. With the money you waste in just one year, you can plug many of those leaks yourself. It’s among the most cost-effective things you can do to conserve energy and increase comfort, according to Energy Star. Start in the attic, since that’s where you’ll find some of the biggest energy drains. Then tackle the basement, to prevent cold air that enters there from being sucked into upstairs rooms. Finally, seal air leaks in the rest of the house. Here are eight places to start.