Measured energy savings and economics of retrofitting existing single-family homes: An update of the BECA-B database

The energy bill for US single-family households was over $77 billion in 1987 (excluding auto fuel purchases), accounting for approximately 20% of national energy expenditures. Large sums are spent on residential retrofits by individual homeowners, government agencies, and utilities. As of late 1987, over 21 million households indicated that they had added at least one energy-saving measure in the previous two years, while a recent Electric Power Research Institute (EPRI) study estimated that nearly 15 million residential customers have participated in some kind of demand-side management (DSM) program. Given the level of continuing investments in residential energy efficiency, accurate estimates of savings from various conservation measures are increasingly necessary, especially as new technologies become more sophisticated and incremental efficiency gains more difficult to achieve. This report provides a comparative analysis of measured data on the performance and cost-effectiveness of energy-saving measures in existing single-family homes, based on information in the Buildings Energy-Use Compilation and Analysis (BECA) data base. The initial BECA report on measured data for single-family retrofits was completed seven years ago. In updating the single-family database, we have added 135 data points, representing over 33,000 houses, to the original database of 145 retrofit projects. The report is organized in two volumes. Volume 1 provides a summary of energy savings and costs of individual retrofit measures and strategies and results from federal/state low-income and utility weatherization programs. we also discuss measurement issues, predicted versus actual savings, trends in single-family retrofit programs, and implications for the next generation'' of cost-effective single-family retrofits. Volume 2 contains a written summary of each retrofit project and complete data tables. 87 refs., 20 figs., 16 tabs