Why Washington is an ADU market worth owning.
The state changed the rules, Seattle permits already grew fourfold, and homeowners are searching. Here's the data, with a source under every number.
Fig. 1 · The law
Washington ADU law in 2026
- Two ADUs per lot in most cities and counties inside urban growth areas
- Attached, detached, or a conversion of an existing building
- Cities must allow at least 1,000 square feet
- No owner living on site required, unless it is a short term rental
- Impact fees capped at 50% of what the main house pays
- Cities had until the end of June 2025 to update their codes
Homeowners in Seattle, Tacoma, Spokane and Vancouver with room in the backyard are now possible ADU jobs.
Sources: Washington State Dept. of Commerce · The Urbanist, Jul 2025
Fig. 2 · The proof it's real
987
ADU permits issued in Seattle in 2023. Four times the 2018 number.
And that was before the state law opened up two per lot and 32 foot height limits in Seattle neighborhood zones.
Source: Seattle OPCD, via The Urbanist, Jul 2025
Fig. 3 · Google cost per click, Washington
What Washington builders pay Google for one click
$32.38adu seattle builders
$22.27adu construction seattle
$19.59adu builders seattle
That's one click. Not a call. We reach Washington homeowners on Facebook and Instagram before they ever search.
Source: SearchAtlas, average cost per click, Oct 2026
Fig. 4 · Monthly Google searches
ADU search demand in Washington
adu construction seattle50
Seattle carries the volume. The rest of the state is early, which means the builders who show up first own it.
Source: SearchAtlas keyword data, US monthly searches, Oct 2026
Fig. 6 · Fit check
Who we work with in Washington
- Custom home builders ready to add ADUs as a service line
- Remodelers who want bigger tickets than kitchen and bath jobs
- GCs with a crew and subs that can handle a 400 to 1,200 square foot build
- ADU builders in Seattle, Tacoma, Spokane and Vancouver who want more volume
Never built one but you've got the license, the crew and the subs? You're who we want to talk to.
Fig. 7 · Questions
Washington ADU marketing FAQ
Are ADUs legal in Washington?
Yes. Washington requires most cities and counties inside urban growth areas to allow two ADUs per lot, attached or detached, of at least 1,000 square feet, with no owner occupancy requirement except for short term rentals. Cities had until the end of June 2025 to comply.
How many people search for ADUs in Washington?
About 484 searches a month across the ADU keywords we track for Washington, led by "adu builders seattle" at 159 a month (SearchAtlas, October 2026). Most of that demand is in Seattle, Tacoma, Spokane and Vancouver.
How does Maverix market ADU builders in Washington?
We run Meta ads to homeowners in your service area, our call rep screens every lead for ownership, budget, financing and timeline, and the ready ones get booked on your calendar. One ADU builder per market. You pay ad spend straight to Meta.
Other markets
ADU marketing in other states
Washington now makes most cities allow two ADUs per lot. The builders who get in front of homeowners now are the ones they call.