All six county plans free
ADUs in Kingston, WA
Free pre-approved plans, site plans, permits and construction for ADUs in Kingston.
Building an ADU in Kingston
Kingston is an unincorporated community with its own urban growth area. Lots inside it can use the free pre-approved plans under the county's urban ADU rules, and Kitsap County DCD issues the permit. Plenty of Kingston-area addresses are outside that boundary, and those lots follow the rural rules instead.
| Inside the Kingston UGA | Up to two ADUs per lot, up to 1,000 square feet each, no owner-occupancy requirement. Urban sewer service is required. |
|---|---|
| Outside the UGA | One ADU per lot. A detached ADU is limited to 900 square feet or half the main house, whichever is smaller, within 150 feet of the house, and the owner must live on site. The county plans are available for a fee (Conditional Use Permit plus a $1,000 design fee). |
| Septic | Lots on septic need Kitsap Public Health review, and an ADU that adds bedrooms can mean a larger system. |
| Parking | Inside the UGA, a first ADU often needs no extra space; a second needs one. Outside it, extra off-street parking is required. |
The first question for any Kingston lot is which side of the boundary it's on. Send us the parcel number and we'll tell you.
State rules that apply
Washington's HB 1337 sets minimums inside urban growth areas: at least two ADUs per qualifying lot, no owner-occupancy requirement, a size cap no lower than 1,000 square feet, and impact fees no more than half of the main house's. Read the HB 1337 guide →
What it costs
For the building, our ADU builds usually run $325 to $550 per square foot depending on finishes. Site work, utility connections and septic are extra. See the cost guide or our packages.
Next steps
Start with a free parcel check. We confirm zoning, the urban growth boundary, sewer or septic and critical areas, then quote the site plan and permit. Questions first? Read the ADU FAQ or call 206.226.1988.
Step 2 · Choose a plan
Plans you can build here
The county's pre-approved plans cost nothing to use in eligible areas. You can pick finishes, colors and roof style, but not structural changes. Need a different layout? Ask us about licensed plans from other architects.
Tick “Compare” on up to three plans to see them side by side. Kitsap and Salish footprints come from the architect's cut sheets; the others are approximate. Renderings: Kitsap pre-approved ADU program (Artisans Group).
Questions
ADUs in Kingston: FAQ
Can I use the free pre-approved ADU plans in Kingston?
Yes. All six Kitsap pre-approved plans can be used for free here when built without structural changes.
Do I still need a permit for an ADU in Kingston?
Yes. You need a building permit from Kitsap County DCD and a site plan for your lot. Pre-approved plans shorten review of the building itself.
How much does an ADU cost in Kingston?
Our builds usually run $325 to $550 per square foot for the building, depending on finishes. Site work, utilities and septic are extra and depend on the lot; we price them after a site visit.
Who can draw my site plan and build the ADU?
Kitsap ADU prepares the site plan and permit package through Laughlin Development and builds through JKM Construction, a licensed Washington general contractor since 2019.