Washington State Energy Codes

Washington State Energy Codes: A Comprehensive Guide

washington state energy code

Key Changes in the 2024 Washington State Energy Codes

Navigate: Washington Building Codes 

The 2024 update to the WSEC introduces features several critical features and changes:

  1. Mandatory Heat Pump Heating: All new single-family homes, townhomes, and multi-family buildings up to three stories must include heat pump heating systems. This mandate applies statewide, with exceptions for rural areas lacking electricity access.
  2. Heat Pump Water Heaters: Heat pump water heaters will become standard in new constructions.
  3. Positioning of Water Heaters and Air Handlers: These appliances must be placed in conditioned spaces to maximize energy efficiency.
  4. Reduced Air Changes per Hour: The allowable air changes per hour in homes will decrease from 5 to 4, improving energy retention.
  5. Stricter Appliance Standards: New homes must comply with stricter Energy Star appliance standards​ (WA Energy Codes)​​ (Lexar Homes)​​ (WSU Energy Program)​.

Impact on Homeowners and Builders

The new codes are expected to increase the cost of new constructions by approximately $14,000 on average. Despite the upfront construction costs, the long-term benefits include significant energy savings and reduced utility bills, contributing to a more sustainable future. Additionally, these updates are projected to deliver 18% more energy savings compared to the 2018 codes​ (Lexar Homes)​​ (WSU Energy Program)​.

Emission Reduction Goals

The updated codes align with Washington State’s broader sustainability goals, aiming to reduce emissions from residential construction, commercial, and other commercial and industrial buildings construction, which accounted for 25% of the state’s total emissions in 2019. The 2024 WSEC updates are a crucial step towards achieving these environmental targets​ (Lexar Homes)​​ (WSU Energy Program)​.

History and Evolution of the State Energy Code

Overview of the Energy Code

  • Washington’s first energy code was adopted in 1977 as a voluntary requirement.
  • The State Building Code Act and State Energy Code Act (SECA) were passed in 1985, giving rulemaking authority to the State Building Code Council (SBCC).
  • The first statewide energy code was adopted in 1986, based on ANSI/ASHRAE/IES Standard 90A-1980.
  • The Washington State Energy Code (WSEC) was amended in 2001, 2004, and 2006 to increase energy efficiency standards.

Residential Energy Code Compliance

Technical Code Support

  • Our energy code team provides support to those who use the residential sections of the Washington State Energy Code (WSEC-R).
  • To determine which version of the WSEC-R a building permit must follow, refer to the date when the permit was issued.
  • If the building permit was issued after [insert date], it must follow the [insert version] of the WSEC-R.
  • The WSEC-R is a state energy code that sets minimum energy efficiency standards for new residential buildings in Washington state.

King County Energy Code Requirements

  • The 2021 Washington State Energy Code (WSEC) is effective for applications deemed complete on or after March 15, 2024.
  • The full code text of the 2021 WSEC is available on the State Building Code Council website.
  • The WSEC is split into two sections: residential and commercial buildings.
  • Pay attention to definitions to determine which provisions to use.

Commercial Energy Code (WSEC-C)

State Building Code Council (SBCC) Role

  • The State Building Code Council (SBCC) was created to provide independent analysis and objective advice on state building code issues.
  • The SBCC establishes minimum building requirements necessary to promote health, safety, and welfare.
  • The SBCC website provides access to the most current and up-to-date WSEC versions and other Washington-specific codes.
  • The SBCC reviews, develops, and adopts the state building code.

Commercial Energy Code Requirements

  • The WSEC-C is contained in the Washington Administrative Code (WAC), Chapter 51-11.
  • The code is divided into two chapters: Residential Energy Code and Nonresidential Energy Code.
  • The Nonresidential Energy Code contains requirements for all other building occupancies.
  • Compliance is determined by plan review and inspection by the local building official.

Energy Code Resources and Support

Additional Assistance and Resources

  • For additional assistance from the Technical Code Support Hotline, call: 360.956.2042 or submit an energy code question through our website. 

Disclaimer and Limitations

  • Any mention of trade names, commercialized products, and organizations does not imply endorsement by Washington State University’s Energy Program (WSUEP).
  • The WSUEP and its collaborators make no warranties or representations regarding the accuracy, completeness, or usefulness of the contents of this publication.
  • The WSUEP is not an affiliate of the Washington State Building Code Council (SBCC) and provides advisory technical support only.