- All homes experience wear and tear. Whether your home is five or 50 years old, chances are good that it can benefit from cost-effective measures to improve its energy efficiency. Wind, vibrations, sunlight and seasonal temperature changes can loosen up a tight home, increasing air leakage; windows may no longer close tightly, and ductwork can spring leaks, wasting huge amounts of heating or cooling energy. Furnaces, air conditioners, and water heaters that have been running for years gradually lose efficiency, especially if regular cleaning and maintenance hasn't been done. All these things...