Energy Code Compliance Evaluations and Code Baseline Review

IEc, with subcontractor Resource Refocus, conducted three mixed-methods evaluations that tested alternative approaches for assessing the market’s response to code changes. The evaluations focus on new-construction single-family homes in Idaho, Montana, and Oregon. Historically, NEEA’s code studies relied exclusively on onsite audits, which are time-consuming, costly, and require builders to grant access to sites. The IEc team tested alternative approaches to assess compliance and model energy savings, including permits, databases of above-code homes, interviews with market actors, building plan sets, and manufacturer invoices. IEc assessed the viability of each data source for each of seven key energy code measures; developed the sample and data collection plans; compiled data from multiple sources, and tiered the data based on how well it is likely to reflect as-built conditions. Throughout the process, we collaborated actively with local market actors to develop and implement the study, and remained flexible and adaptable in response to data availability and limitations. IEc also piloted new sampling approaches for rural areas to accurately report energy savings and inform training and compliance support efforts.

The IEc team assessed compliance both at the individual measure level and whole home level (using modeling analysis to estimate the energy consumption of both an observed and code-compliant population of homes) and conducted a savings analysis to project the potential savings with improved energy code compliance. The studies provided recommendations to enhance code compliance through outreach, education, and related support activities as well as recommendations for future code studies. Recently, the IEc team conducted a Code Baseline and Assumption Review for commercial and residential energy codes in the Northwest, based on interviews with individuals familiar with Northwest and national building energy code development and a review of codes savings evaluation approaches from across the country.