County plans for a fee · rural rules
ADUs in Rural Kitsap County
County plans with a conditional use permit, licensed plans, site plans, septic coordination and construction for ADUs on rural Kitsap lots.
Rural Kitsap ADUs
Kitsap County says rural-zoned lots can use the pre-approved plans for a fee: a Conditional Use Permit, the CUP fees, and a $1,000 design fee. A licensed plan from another architect is the other route.
| Number | One ADU per lot, attached or detached, not both. |
|---|---|
| Detached size | No more than 900 square feet or half the main house's living area, whichever is smaller, by interior dimensions. That rules out the 1,000 SF Salish on most rural lots. |
| Attached size | No more than half the main house's living area. |
| Location | A detached ADU must be within 150 feet of the main house, or be a conversion of an existing building such as a garage. |
| Owner occupancy | Required: the owner must live in the main house or the ADU. |
| Parking and access | Extra off-street parking, using the same entrance as the main house. |
| Septic and water | Must meet Kitsap Public Health standards. An ADU that adds bedrooms can mean a larger septic system. |
Rural lots also more often include wetlands, streams or slopes with buffers. Septic is usually the item that decides the budget, so we look at it first.
State rules that apply
HB 1337's minimums apply inside urban growth areas. Rural lots follow Kitsap County's own ADU rules, including owner occupancy. 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
County plans under the rural 900 SF limit
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 rural Kitsap County: FAQ
Can I use the free pre-approved ADU plans in rural Kitsap County?
Yes, for a fee. Kitsap County says rural-zoned lots need a Conditional Use Permit, its fees, and a $1,000 design fee. The 1,000 SF Salish is too big for most rural lots.
Do I still need a permit for an ADU in rural Kitsap County?
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 rural Kitsap County?
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.