Energy use in residential buildings in the U.S. is significant-about 20% of primary energy use. While several approaches reduce energy use such as appliance standards and utility programs, enforcing state building energy codes is one of the most promising. However, one of the challenges is to understand the rate of compliance within the building community. Utility companies typically use these codes as the baseline for providing incentives to builders participating in utility-sponsored residential new construction (RNC) programs. However, because builders may construct homes that fail to meet energy codes, energy use in the actual baseline is higher than would be expected if all buildings complied with the code. Also, builders participating in utility-sponsored RNC programs may have a higher frequency and level of building compliance than nonparticipating builders, resulting in additional resource savings. As a result, the measured savings from RNC programs may underestimate actual savings unless program participants' compliance with energy codes is taken into account.
In our analysis of six studies of building compliance in two regions of the U.S., the Pacific Northwest and California, we found a high number of violations in plans, in the field, and in energy impacts. However, where total energy consumption was calculated, on average the houses complied with the codes because the energy savings from the houses that saved more energy than called for by the code compensated for the excessive energy use of those that did not.
In three studies, compliance with state building codes was shown to be higher for participants in utility RNC programs than for nonparticipants. For example, in the evaluation of Pacific Gas & Electric's 1992 RNC program, nonparticipating homes in PG&E's service territory were, on average, built 6% below (i.e., did not meet) California's building energy codes based on calculated energy usage across all measures and equipment. In contrast, builders/contractors who agreed to participate in the PG&E program achieved 100% compliance. In a follow-up study, PG&E's program was found to have increased both the frequency and level of compliance with codes in the utility's service territory. Although both participating homes and non-participants were found, on average, to comply with California's code, the compliance margin of participating homes was nearly twice as great as that for nonparticipants. Furthermore, nonparticipant homes were more than ten times as likely to fail to comply than participant homes.
California, Oregon, and Washington have spent considerable resources on improving the expertise of builders and building code officials through training and educational programs. In addition, many jurisdictions in these states have had more than 15 years of experience with energy-efficiency codes, code support (by utilities, local government, and code officials), and code enforcement. In contrast, areas in the country with less experience and expertise will undoubtedly experience higher rates of noncompliance with state building codes. Accordingly, we believe utility RNC programs in other states could be more cost-effective if utility regulators recognized the role of RNC programs in increasing compliance with existing state building codes, or, conversely, if they recognize the general degree of noncompliance among nonparticipating builders. Finally, we expect the issue of building code compliance to continue to be an important research topic as utilities and governmental agencies promote energy efficiency through market transformation efforts. Market baselines (such as code compliance) are critical to evaluating the effectiveness of these efforts.
Energy Analysis Program
(510) 486-6047; (510) 486-4673 fax
For more information, request Ed Vine's paper presented at the 1996 ACEEE Summer Study: "Residential Building Code Compliance: Implications for Evaluating the Performance of Utility Residential New Construction Programs," LBL-38382.
This work was sponsored by Department of Energy's Office of Utility Technologies.