ADU questions, answered

Most Kitsap lots with a house can have at least one ADU. What decides it is zoning, whether the lot is inside an urban growth area, setbacks and lot coverage, sewer or septic capacity, and critical areas like wetlands or steep slopes. Send us the address or parcel number and we'll check it free.

Inside the cities and the county's urban growth areas, you can have up to two ADUs per lot, up to 1,000 square feet each, with no owner-occupancy requirement, and the county plans are free. On rural lots you get one ADU; a detached one is limited to 900 square feet or half the main house, must be within 150 feet of it, and the owner must live on site. Rural lots can use the county plans with a Conditional Use Permit and a $1,000 design fee.

The county's maps show the boundary, and many Silverdale, Kingston and Port Orchard-area addresses sit near it. We check it as part of the free parcel check.

In urban growth areas, yes: state law (HB 1337) and Kitsap County's code allow up to two per qualifying lot. Rural lots are limited to one.

Not in urban growth areas; HB 1337 bars owner-occupancy requirements there. On rural Kitsap lots with a detached ADU, the owner must live in the house or the ADU.

Often, yes, but septic is usually the biggest variable. Kitsap Public Health reviews the system, and an ADU that adds bedrooms can mean a larger or new system. Urban ADUs in unincorporated Kitsap must have urban sewer service, and Poulsbo says a septic house may need to connect to sewer.

Sometimes. Poulsbo, for example, says an ADU may use the main house's existing water and sewer connections if they meet code. Power usually comes from the house panel or a new service. We check capacity in the parcel review.

Our builds usually run $325 to $550 per square foot for the building, depending on finishes. Site work, utility connections and septic are extra and depend on the lot, so we price them after a site visit.

For the county plans in unincorporated Kitsap, the county publishes approximate permit fees from about $4,700 (Lille) to about $7,200 (Kitsap). Impact and connection fees can apply on top, and cities set their own fees.

Common routes are cash, a home equity line of credit, a cash-out refinance, or a construction or renovation loan. Lenders differ on how they count future ADU rent. This isn't financial advice; talk to a lender about your situation.

Yes, in Bainbridge Island, Bremerton, Port Orchard, Poulsbo and the county's urban areas, when built without structural changes. We never charge for them; we charge for the site plan, permit work and construction.

It depends on the jurisdiction, its review queue and how complete the application is. Pre-approved plans skip review of the building's design, structure and energy code in places like Bainbridge Island, so review focuses on the site plan. We give you a timeline with your quote.

A detached ADU (a backyard cottage) gives the most privacy and is what the county plans are designed as. An attached ADU or a conversion inside the house can cost less when the space already exists. On rural lots, an attached ADU is limited to half the main house's living area.

Only non-structural choices: window colors and operation, roof pitch, style and materials, eaves, siding, doors, lighting and most interior walls. Structural changes take it out of the pre-approved path.

In Kitsap's urban growth areas, a first ADU often needs no extra space if the main house meets its parking requirement or street parking is available; a second needs one off-street space. Rural ADUs need extra off-street parking. Cities have their own rules; Bainbridge generally asks for one space.

Long-term rental is common. Short-term rental rules vary; Bainbridge Island requires a business license for short-term rental use.