2019-2020 Washington Residential New Construction Code Study

The Northwest Energy Efficiency Alliance (NEEA) contracted with CLEAResult to conduct research to better understand how the 2015 Washington State Energy Code (Residential Provisions) has affected new home construction and energy performance. The research team visited building code offices and single-family residences between September 2019 and January 2020. In the end, 184 houses were visited in 37 jurisdictions throughout the state. Analysis of the data provides insight into how, among options available, builders are choosing to comply with the energy code, observed levels of compliance, and expected home energy performance. 

The study finds that builders’ most commonly used options are high-efficiency furnaces/heat pumps and low-flow shower heads and faucets. Non-compliance observed in as-built homes is estimated to result in energy use that is 4.5% greater than if all homes were built to comply with code.

Updated as of 09/16/2020

The accompanying data for this study is available by request via email.

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