A consumer should select a window company who sells energy efficient products, has a reputation for service and stability, and provides a warranty on the unit. We recommend that you buy from a company with a commitment to participating in the National Fenestration Rating Council (NFRC) certification and labeling process and in the ENERGY STAR® Windows program.

Many companies will also participate in the American Architectural Manufacturers Association (AAMA) and will have a permanent label on the product indicating their participation. Membership in all of these organizations is an indication that you are dealing with a manufacturer who cares about the quality of their product and the product's energy efficiency.