Building a better understanding of home energy efficiency in CA
In May 2015, Res-Intel started working with Southern California Edison (SCE) to analyze the monthly electricity consumption of new single family residential (SFR) homes that participated in the California Advanced Home Program (CAHP) between 2011 and 2014. The CAHP program gave incentives to homebuilders who designed and constructed homes that were at least 15% more efficient than California building codes required at the time.
The intent of the study was to determine if the average energy-use in these new homes varied between CAHP builders in SCE service territory. Res-Intel computed the energy consumptions of each SFR as a Home Energy Intensity Score (HIS) measured in kWh/ft2/day and compared their distribution. Of the twenty-six builders included in the analysis, two were determined to construct more energy efficient homes and two others were found to be less efficient. Overall, the results showed that performance among CAHP builders is relatively homogenous.
It is important to note that HIS is an “operational” measure of energy efficiency, meaning that the results are impacted by human behavior. Some communities might attract families with more children or a greater share of retirees, both of which can increase a home’s energy consumption. Recommendations for further assessment of the CAHP program included developing an understanding of the effect of regional and demographic differences on energy intensities, as well as taking a closer look at unique characteristics of top-performing builders, including their staff training programs and building practices.
Res-Intel is a national leader in mass-scale benchmarking of residential buildings. Its benchmarking engine provides micro-targeted recommendations for property owners and managers to cost-effectively reduce energy and water usage. The Res-Intel software platform has been partially funded under California Energy Commission Public Interest Energy Research grant #57356A/11-12 and #58076A/14-09G.