How can houses be more energy efficient

9 Ways to Make Your Home More Energy-Efficient :
1. Make sure your walls and attic are well insulated.
2. Upgrade or replace windows.
3. Plant shade trees and shrubs around your house.
4. Replace an older furnace with a high-efficiency system.
5. Improve the efficiency of your hot water system.
6. Replace incandescent light bulbs with compact fluorescent lamps (CFLs).
7. If you buy a new refrigerator, don’t leave the old one plugged in.
8. Take advantage of new tax incentives to improve your home.
9. Schedule an energy audit for more expert advice on your home as a whole.