Poulsbo allows up to two accessory dwelling units (ADUs) on every residential lot, each up to 1,000 square feet, with a detached ADU capped at 25 feet in height. Each ADU needs one off-street parking space unless it sits within half a mile of a major transit stop, and no ADU may be a short-term rental. ADUs are approved through a standard building permit, and the city’s Permit Ready ADU program offers pre-approved plans from 480 to 1,000 square feet.
Those are the rules under Poulsbo Municipal Code (PMC) 18.70.070 as the city publishes them in 2026. This guide comes from a Poulsbo-based architect in Poulsbo. It walks through each rule and what Washington’s 2023 ADU law changed. It also shows how to choose between a Permit Ready plan and a custom design for your lot.
Poulsbo is an incorporated city. ADUs inside the city limits follow the Poulsbo Municipal Code, not Kitsap County’s code. The county’s rules apply only to unincorporated areas such as Silverdale, Kingston and Hansville. If your parcel is in the city, this is the table that matters.
| Standard | Poulsbo rule (PMC 18.70.070) |
|---|---|
| Where allowed | All residential zoning districts, attached or detached |
| Number per lot | Two ADUs per principal residence: one attached plus one detached, two attached, or two detached (in one or two structures) |
| Maximum size | 1,000 square feet each, excluding garages, storage under 5 feet tall, porches and covered decks |
| Height | Detached ADU: 25 feet. Attached ADU: the limit that applies to the main house (35 feet in residential zones) |
| Setbacks and lot coverage | Same zoning standards as any building on the lot |
| Parking | One off-street space per ADU, unless within one-half mile walking distance of a major transit stop; tandem parking allowed |
| Rentals | No short-term rentals; minimum rental term of 90 days |
| Approval | Building permit, issued by the Building Department and reviewed by Planning and Economic Development |
Source: City of Poulsbo, Planning – Accessory Dwelling Units and the city’s Accessory Dwelling Unit handout (2024). The municipal code is the controlling document, so confirm the current text with Planning and Economic Development before you design.
Two. Poulsbo permits two accessory dwelling units per principal residence in every residential zone. The code lists three configurations: one attached and one detached, two attached, or two detached units in one or two structures. The lot still has to satisfy its zone’s setbacks, lot coverage and height limits for all of the buildings together. That is where most two-ADU plans succeed or fail.
A guest house is a different thing: a detached accessory building with no kitchen, limited to one per lot, 800 square feet and 25 feet. Add a kitchen and it becomes an ADU.
Each ADU may contain no more than 1,000 square feet, excluding garages, storage areas under five feet in height, porches and covered decks. One exception: an ADU located entirely on the ground floor or basement of the main house may be larger. It can use all of that floor area, as long as every other standard is met.
A detached ADU is limited to 25 feet and must be separated from the primary residence as the building code requires. An attached ADU is limited to the main house’s height, which in Poulsbo’s residential zones is 35 feet.
Poulsbo measures height as the average of all building sides, from finished grade to the top of each wall, as shown in the city’s Measuring Height handout (September 2024). On a sloped Poulsbo lot that averaging rule is the difference between a loft that fits and one that does not.
The ADU must meet all of the zoning development standards for its lot: setbacks, lot coverage, impervious surface and height. There is no reduced setback for being small. The relief valve is the conversion rule. An existing structure that does not comply with certain development standards may still become an ADU if it meets PMC 18.70.070 A(4).
Washington’s statewide ADU law (RCW 36.70A.681) requires cities to allow conversions of existing structures such as detached garages. That applies even where the structure violates current setback or lot coverage rules. A legally built garage on the side property line is therefore a realistic ADU candidate.
Critical areas override all of this. If the lot has a wetland, stream or steep slope on or near it, the city’s buffers apply. The Permit Ready handout notes that additional setbacks and reports may be required before a permit is issued. Shoreline lots along Liberty Bay also fall under the city’s Shoreline Master Program. A feasibility study before design settles these questions on paper rather than in plan review.
In 2023 the Legislature passed House Bill 1337, now codified at RCW 36.70A.681. It sets a floor that every city and county planning under the Growth Management Act must meet inside urban growth areas, and Poulsbo’s current code already reflects it. These are the statute’s main limits on local regulation.
The Municipal Research and Services Center (MRSC) summarizes the law on its Accessory Dwelling Units page. It names Poulsbo as one of the cities that prohibits ADUs as short-term rentals. One carve-out: the statute does not apply to lots designated with critical areas or their buffers. A wetland or steep-slope lot in Poulsbo is governed by the city’s critical areas ordinance first.
To speed up ADU permitting, Poulsbo joined Bremerton, Bainbridge Island and Port Orchard in a Permit Ready Accessory Dwelling Unit (PRADU) program. The city provides pre-approved, designed and engineered model base plans to residents and builders, in sizes from 480 to 1,000 square feet. The city’s Permit Ready ADU page currently lists these models:
| Model | Size | Layout |
|---|---|---|
| The Lille | 480 sq ft | One bedroom, single story |
| The Sidney | 600 sq ft | One bedroom, single story |
| The Sinclair | 800 sq ft | Two bedrooms, single story |
| The Blakely | 800 sq ft | Two bedrooms, two stories |
| The Salish | 1,000 sq ft | Three bedrooms |
| The Kitsap | 672 to 834 sq ft | One bedroom, two stories, over a two- or three-car garage |
What the program does not do is design your site. The city’s June 2025 Permit Ready ADU handout says you still need a site plan showing the unit relative to property lines, setbacks, utilities and any critical areas. It strongly recommends a survey. You can choose the roof style, siding, color, windows and doors. Any other change means working with an architect, and modifications may disqualify the plan’s pre-approved status.
The city’s own page says residents are not required to use a pre-approved design; your own plans simply go through the standard review. In our experience as the ADU design studio based in Poulsbo, the decision comes down to the lot, not the plan.
| Your situation | Better fit |
|---|---|
| Flat lot, generous yard, a standard footprint fits inside the setbacks | Permit Ready plan, with finish choices only |
| Sloped lot, Liberty Bay views, or a critical-area buffer that pushes the footprint | Custom design that responds to the slope, the buffer and the views |
| A second ADU, or an ADU plus a garage, under one lot-coverage number | Custom design, planned for the whole lot |
| Converting an existing garage or basement | Custom design; the model plans assume new construction |
| A model plan is close but needs a changed window wall, entry or roof form | Architect-adapted plan, submitted under standard review |
Poulsbo’s rules are permissive by design. The limiting factors on most in-town lots are mature trees, slope, a shoreline or wetland buffer, and the relationship between the new unit and the house next door. Those are design problems, and a stock plan cannot solve them on its own.
Bluefoot Architecture & Design works from a studio on Front Street in Poulsbo, a short walk from the city’s planning office. Principal Architect Jay Volz and interior designer Michele Doyle bring more than 40 years of combined experience. The studio was named 2026 Best of Kitsap for Best Architect in North, Central and South Kitsap. Every ADU follows the same five-phase process:
If your property is outside the city limits, the rules differ. Our Kitsap County ADU design guide covers the county’s standards for unincorporated lots inside and outside the urban growth area.
Two accessory dwelling units per principal residence are permitted in Poulsbo’s residential zones. They may be one attached and one detached unit, two attached units, or two detached units in one or two structures. Each must meet the zone’s setbacks, lot coverage and height limits, and each is capped at 1,000 square feet.
Up to 1,000 square feet, not counting garages, storage areas under five feet tall, porches and covered decks. An ADU located entirely on the ground floor or basement of the main house may exceed 1,000 square feet. It can use all of that floor area, provided every other standard is met.
No. Poulsbo Municipal Code 18.70.070 does not permit an ADU to be used as a short-term rental, and the unit must be rented for a minimum of 90 days. Long-term rental, family housing and a home office are all allowed uses.
No. Washington’s RCW 36.70A.681 prohibits cities from requiring the owner to occupy either the main house or the ADU, and Poulsbo’s code contains no owner-occupancy requirement.
Partly. You can choose the roof style, siding, color, windows and doors. Any other change requires working with an architect. The city notes that modifications may disqualify the plan’s pre-approved status, so the altered plan goes through standard review instead.
You may be adapting one of the city’s Permit Ready plans or designing a unit from scratch for a sloped lot above Liberty Bay. Either way, Bluefoot Architecture & Design can confirm what your Poulsbo lot allows and design an ADU that fits it. Contact our Poulsbo studio or call 360-602-2965 to start the conversation.