New Building Code Provisions Ease Path to Passive House in Washington State
And Offer a Template for Other States to Follow
Last month, HB 1183 was passed in Washington. It's a first-of-its-kind bill that makes it easier to build new and retrofit Passive House buildings across the state, and it's something that Passive House supporters (and especially Passive House Cascadia member Rob Harrison!) have been advocating for since 2019.
Officially signed into law on July 27th, HB 1183 incentivizes Passive House buildings by updating the building code. Some of the included provisions also apply to affordable housing, mass timber, and modular housing. You can see the full text of HB 1183 here, but below is a rundown of the specifics from Rob himself:
- This law allows walls containing insulation to project into all setbacks by an additional eight inches—including existing non-conforming buildings, as long as the space between dwellings remains greater than three feet.
- It allows roofs to be higher by eight inches.
- It allows an extra four feet above the height limits for photovoltaic panels.
- It prevents jurisdictions from requiring onsite parking as a condition of permit approval, because the cost of providing onsite parking in a parking garage adds substantial per-unit costs on a larger project, and can make a smaller project entirely infeasible.
- It sets reasonable minimum sizes for dwelling units. (Jurisdictions have used setting large minimum unit sizes as a means of preventing some types of affordable housing).
- Passive House floor area will be measured from the inside of drywall rather than the outside face of the wall, which removes the penalty for the thicker walls in Passive House where there are square footage limits, such as with backyard cottages.
Taken together, these provisions make Passive House easier to design and build in Washington State, which means more affordable, resilient, durable, and comfortable housing can support the health, wellness, and wallets of Washington communities.
These provisions can also serve as a template for Passive House advocates to point to when petitioning local governments for better building codes that favor the Passive House standard. Local governments often hesitate to be the first to set the trend—with Washington State leading the way, we have an example to look to. (For more examples, check out our 2023 brief, Stepping Up to Passive: Policies We Want.)
Rob would like to thank Representative Davina Duerr, who sponsored the bill, Dan Bertolet, Housing and Urbanism Director of Sightline Institute, who was there through the whole process helping the bill along and who pushed for the parking provision, David Neiman of Neiman Taber Architects, who contributed the dwelling unit size provisions in the bill, Julie Blazek, who articulately testified in favor of the bill many times, and David Neiman and Nathan Torgelson, who have been advocating for these provisions alongside Rob since 2019.
Great things can happen when we advocate for better building codes! We invite you to build a coalition and push for Passive House in your state. You can get started by attending your regional Chapter Meetings.
