Metaevaluation of National Weatherization Assistance Program Based on State Studies, 1993-2002

The National Weatherization Assistance Program, sponsored by the U.S. Department of Energy (DOE) and implemented by state and local agencies throughout the United States, weatherizes homes for low-income residents in order to increase their energy efficiency and lower utility bills. Research staff members at Oak Ridge National Laboratory (ORNL) have performed two previous metaevaluations of this program (Berry, 1997; Schweitzer and Berry, 1999). Both of these earlier metaevaluations involved synthesizing the results from individual studies of state weatherization efforts completed during a several year period. This report is the third in a series of metaevaluations of state-level studies. It is built on the foundation developed by the previous two metaevaluations. The purpose of this report, like that of the two earlier ORNL metaevaluations, is to provide a current estimate of the average national energy savings per home weatherized for the Weatherization Assistance Program based on the relevant state-level studies. All three of the metaevaluations, including this one, were designed to be updates to the findings of a national evaluation of the Weatherization Assistance Program, which examined a representative national sample of several thousand structures weatherized in 1989 (Brown, Berry, Balzer, and Faby 1993). Although the first and second metaevaluations used separate sets of state-level studies, completed during different time periods, there was little difference in their findings about the typical national energy savings per weatherized home for homes that heat with natural gas. Our initial analysis efforts for this report involved repeating the same procedures that had been used in the previous two reports. In particular, we collected and examined only the state-level evaluations that had become available between September of 1998 and August of 2002. Once again, we found little difference in the average energy savings estimates per weatherized home that were produced with this third set of the most recently available state-level evaluations