Why Replace Your Home’s Windows? The National Association of Home Builders published a study in 2007 stating that aluminum windows are only expected to last 15-20 years. Wooden windows have a life expectancy of approximately 30 years. The wear and tear on older windows can cause them to require replacement for a variety of reasons including: -Energy Efficiency: The U.S. Department of Energy asserts that heat loss from inefficient windows is responsible for 10-25 percent of a consumer’s home heating costs. Installing new windows from a dependable, local Denver contractor like JDI Windows can dramatically improve efficiency and lower heating.