Measure Retention Study: Revised Lifetimes for a Residential Weatherization Program

David Weitzel and Lisa A. Skumatz, Skumatz Economic Research Associates, Inc.

Keywords

Abstract

As part of a large-scale process and impact evaluation study of a weatherization and education program in New England, the authors conducted a measure retention study. The assessment involved a combination of on-site and telephone surveys to gather data for the retention analysis. This analysis was designed to determine whether ex ante measure lifetimes are viable estimates of real measure lifetimes as components of calculating program savings or impacts, and cost-effectiveness.

The participant survey (849 households) was conducted in March and April 2001, and asked for information about installation and removal dates for a number of program measures including: compact fluorescent lights; torchiere lights; refrigerators; faucet aerators; showerheads; basement window coverings; water heater wraps or blankets; thermostats; and furnaces. Although other measures were installed under the program, they were not included in the retention analysis because they represented a small portion of the program savings, they were installed less frequently, or they posed difficulty in identifying their remaining functionality (e.g. caulking).

We found that there were significant removals of several important measures under the program. We fitted hazard functions and estimated effective useful lifetimes (EULs) based on field data. The analysis showed significant differences between ex ante and ex post EULs for two measures, leading to suggested revisions to EUL estimates for the measures.