Fact sheet: Commercial Replacement and Attachment Window Solutions
Window upgrades in existing buildings offer a significant opportunity to improve building envelope thermal performance, reduce heating, ventilation, and air conditioning (HVAC) loads, and enable downsizing of HVAC systems in need of replacement. Although windows on average comprise approximately 15% of a building’s exterior surface, they are responsible for HVAC losses of about 40%. That equates to roughly 12% of a typical building’s overall energy use.
