A new report sponsored by USGBC and Joint Center for Housing Studies at Harvard University suggests that energy reduction tax incentives for green remodeling proved promising for growth in the residential real estate market. Energy consumption per square foot of housing built before 1990 fell by 21.6% from 1993 to 2005. While some of this gain may reflect conservation, it more likely resulted from improvements that increased energy efficiency, raising the marketability and value of these homes