Pre-Approved Accessory Dwelling Unit (ADU) Plans
Kitsap Regional Coordinating Council (KRCC) is excited to have begun our collaborative work to develop pre-approved Accessory Dwelling Unit (ADU) plans for use across Kitsap County, including in the cities of Bainbridge Island, Bremerton, Port Orchard, and Poulsbo. This page provides background information and answers frequently asked questions about the project at this stage of the process. Once pre-approved plans are published, this page will host the plans and supporting materials.
The images below are renderings provided by the architect Artisans Group of four of the pre-approved plan sets.
The video below is a recording of Artisans Group’s presentation about the ADU project at the KRCC Board meeting on May 6, 2025. It includes a summary of the process, an overview of each of the four plan sets, and information about initial concepts for two additional plan sets.
What is an ADU? An accessory dwelling unit (ADU) is a smaller, independent residential dwelling unit located on the same lot as a stand-alone (i.e., detached) single-family home. ADUs go by many different names throughout the U.S., including accessory apartments, secondary suites, and granny flats. (Source: American Planning Association)
What is a pre-approved ADU plan? KRCC is working with an architect to develop architectural plans for several different types of ADUs. These basic plans will be reusable construction plans that will be pre-approved by jurisdictions in Kitsap County and can be used by residents and builders for faster permitting. The availability of these plans will support affordable housing efforts by making it easier and less expensive for community members to build ADUs on their property.
Where will I be able to use these ADU plans? The pre-approved ADU plans will be available for use within Kitsap County, including within the city limits of Bainbridge Island, Bremerton, Port Orchard, and Poulsbo.
How much will it cost to use a pre-approved ADU plan? Anyone can use a pre-approved ADU plan in urban areas of Kitsap County and anywhere in Bremerton, Bainbridge Island, Port Orchard, or Poulsbo for free, as long as no modifications to the plan are made. The plans are not free to use in rural areas of unincorporated Kitsap County, which are defined as any area that is not in an Urban Growth Area (UGA) or Type I Limited Area of More Intensive Rural Development (LAMIRD). If your property is not eligible for a free plan, you can purchase the plan sets for $1,500 - $2,500 from the architect. If you live in unincorporated Kitsap County, you can determine whether you live in an area that is eligible for free plans by visiting the Kitsap County Pre-Approved ADU webpage.
What review processes will I need to go through to use the plans? Permit-ready building plans will be available by request from Kitsap County, Bainbridge Island, Bremerton, Port Orchard, and Poulsbo. Please visit the websites of the jurisdiction where you wish to construct an ADU for local process requirements and information.
How many plans will there be? By fall 2025, the goal is to have six different pre-approved plan sets to choose from. The plan sets will range in size and footprint.
When will the pre-approved plans be available? KRCC aims to make four pre-approved plans available in spring 2025. An additional two pre-approved plans are expected to be available in fall 2025.
