Basement
By finishing your basement, you can add living space without adding to your energy budget. Insulate basement walls and crawl spaces based on recommended levels. Seal air leaks around plumbing and wiring holes on outside walls. Replace older, single-pane windows with glass block or ENERGY STAR®-certified high-performance windows. It's also a great opportunity to replace your old clothes washer and dryer with new, ENERGY STAR models.