ADU guides for Kitsap homeowners
What the rules say, what it costs, and what your permit needs, written for Kitsap lots.
Kitsap's pre-approved ADU plans, explained
The six free Kitsap pre-approved ADU plans: where you can use them, what you can change, permit fees, and what you still need for a permit.
Read →State lawWashington's ADU law (HB 1337) for Kitsap homeowners
HB 1337 in plain English: two ADUs per lot in urban growth areas, no owner-occupancy rule, 1,000 SF minimum size cap, parking and impact fee limits.
Read →BudgetWhat does an ADU cost in Kitsap County?
What it costs to build an ADU in Kitsap: $325–$550 per SF for the building, plus site work, utilities, septic and permit fees, and what moves the number.
Read →Permit prepADU site plan checklist
Everything an ADU site plan needs to show for a Kitsap building permit: lines, setbacks, utilities, drainage, parking, critical areas and calculations.
Read →ProcessHow ADU permitting works in Kitsap
How ADU permitting works in Kitsap, step by step: feasibility, plans, site plan, septic, applying, review, inspections, and where to apply.
Read →Where to start
If you're early, read them in this order. The pre-approved plans guide tells you whether the free county plans can work on your lot. The HB 1337 guide covers what state law now guarantees inside urban growth areas. The cost guide gives you the per-square-foot range we see and what sits outside it. Then the site plan checklist and the permit process walk through what the permit actually needs.
Rules for your town
Each jurisdiction adds its own details. See Poulsbo, Bremerton, Bainbridge Island, Port Orchard, Silverdale, Kingston and rural Kitsap. Quick answers are on the FAQ page.
We check these guides against the county and city pages and update them when the rules change. They're general information, not legal advice; we confirm the rules for your specific lot.