2024 Washington State Energy Code Update

March 11, 2024
Blog cover photo for the Washington state energy code update 2024 featuring a Lexar Homes truck and scenic views of Lake Coeur d'Alene in Idaho

2024 Washington State Energy Code Update

After a recent hearing by the Thurston County Superior Court Judge, the most recent energy code will go into effect as planned on March 15th, 2024.


The upcoming Washington State Energy Code Update (WSEC), which has experienced multiple delays in implementation, will significantly impact the real estate sector – especially for those planning to build a custom home on their land. This code, which comes into effect on March 15th 2024, presents an opportunity for future homeowners to make informed decisions and take actionable steps towards realizing their dream home.

Why should you, as a future homeowner, care about this? A reported 25% of Washington State’s emissions in 2019 came from residential, commercial, and industrial buildings. The 2024 code update is predicted to reduce these emissions. It’s not just about making homes more energy-efficient; it’s about creating a more sustainable future for all. It’s also important to understand the changes and how they affect the balance between needing more energy efficiency in building and the need for more housing. The need for more housing in Washington state is urgent. Projections suggest that Washington State will require 1.1 million homes in the next 20 years to meet demand and maintain affordability. Check your county’s housing needs here.


While the WSEC updates are projected to provide 18% more energy savings than the 2018 code for the consumer, they’re also projected to add an average of almost $14,000 to the cost of building according to the BIAW. At Lexar Homes, we’ve always kept healthy home designs and energy efficiency at the forefront of our thinking when it comes to building a home and are ahead of the curve with our standards. This means that if you start building your custom home now and have your plans approved before the new code comes into effect, you stand to benefit from both a cost-savings AND energy savings perspective. 

What’s Changing?

The changes affect new single-family homes, townhomes, and multi-family buildings up to three stories tall, including:


  • Mandatory heat pump heating, except for rural areas with no access to electricity.
  • Heat pump water heaters as standard.
  • The positioning of water heaters and air handlers in conditioned spaces.
  • A reduction in air changes per hour within homes, lowering it from 5 to 4.
  • Stricter Energy Star appliance standards.

The changes in the 2024 Washington state energy code update will have significant benefits, not just in terms of energy conservation, but also cost savings for homeowners. Now is the time to build your dream home. Reach out to us at Lexar Homes today. Our team is ready to help you understand these changes and navigate the path to your new custom home!