This paper describes an end-use analysis of the national energy requirements of US residential window technologies. The authors estimate that the current US stock of 19 billion square feet of residential windows is responsible for 1.7 quadrillion BTUs (or quads) per year of energy use--1.3 quads of heating and 0.4 quads of cooling energy--which represents about 2% of total US energy consumption. They show that national energy use due to windows could be reduced by 25% by the year 2010 through accelerated adoption of currently available, advanced window technologies such as low-e and solar control low-e coatings, vinyl and wood frames, and superwindows. The authors evaluate the economics of the technologies regionally, considering both climatic and energy price variations, and find that the technologies would be cost effective for most consumers
