Bolthole Index

Kitsap County, Washington

Building permits, zoning and septic rules in Bainbridge Island, Washington

Bainbridge Island, Washington adopts and administers its own zoning, and building permits inside city limits come from the city's Planning & Community Development department, not Kitsap County.12 Septic systems still need approval from the Kitsap Public Health District.3 Kitsap County's unincorporated-area rules do not apply on the island's city parcels.

At a glance

Zoning
City zoning (BIMC Title 18), administered by the city1
Building permit
Required; issued by city Planning & Community Development (confirmed for accessory dwelling units)2
Septic
Kitsap Public Health District approval where septic is used instead of public sewer3
Accessory dwelling units
One per parcel, no RVs as ADUs4
Short-term rental of an ADU
Only with an approved business license5

Who to call

Building permits

City of Bainbridge Island Planning & Community Development

Building permits, land-use and zoning review, and development engineering inside Bainbridge Island city limits

206-780-3750

280 Madison Avenue N Bainbridge Island , WA 98110

Septic permits

Kitsap Public Health District

Septic (on-site sewage) permits and inspections, including for addresses inside Bainbridge Island

360-728-2007

345 6th Street, Bremerton, WA

Contact details are copied from each office’s official page and were checked against it on October 14, 2026.

Off-grid gear

Going off-grid in Bainbridge Island means bringing your own water and power. The kit we’d start with:

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Does Bainbridge Island have zoning?

Yes. The City of Bainbridge Island adopts and administers its own zoning for land inside city limits under BIMC Title 18.1 Residential land is divided into districts from R-0.4 through R-14, and each district sets its own minimum lot area and lot coverage.6

In R-2, the minimum standard lot is 20,000 square feet and base lot coverage is 20%.78 The most rural-feeling R-0.4 district requires 100,000 square feet per lot.7 Shoreline, critical-area and other overlays can add requirements on top of the base district.1

Subdividing is regulated too: resubdivision must follow the city's flexible lot design requirements.9

Do you need a building permit in Bainbridge Island, and who issues it?

Building permits inside Bainbridge Island come from the city's Planning & Community Development department (PCD). The city's own flyer states that the owner or applicant must apply for an accessory dwelling unit building permit with PCD.2 We confirmed that rule for accessory dwelling units; we could not confirm the city's general new-home permit rules, so call PCD before assuming an exemption for any structure.10

PCD can be reached at 206-780-3750 and its counter at 280 Madison Avenue N is open for 15-minute question sessions Monday to Friday.10 Applications go through the city's public permit portal.11

Additional reviews apply: land use, fire and development engineering review the project alongside the building department.11 Fees are calculated at payment.12

How do septic permits work in Bainbridge Island?

Where a Bainbridge Island property uses septic rather than public sewer, approval from the Kitsap Public Health District is required.3 The city, not the health district, handles the building permit; the two are separate approvals.

Properties must connect to public sewer and water where available.13 Kitsap County's rules say a new septic system needs a Building Site Application approved before the septic installation permit, and a new system is inspected before it is covered.1415 Washington requires a permit for installing, repairing or expanding any on-site sewage system.16

Contact the Kitsap Public Health District at 360-728-2007.17

Can you add an accessory dwelling unit or live in an RV in Bainbridge Island?

An accessory dwelling unit (ADU) may be attached or detached on a single-family lot, limited to one per parcel and generally 1,000 square feet or less.4 No recreational vehicle may serve as an ADU.4 A detached ADU must meet zone setback and lot-coverage standards.4

An ADU cannot be a short-term rental such as an Airbnb unless the owner holds an approved business license for that use.5

We could not confirm the city's rules on living in an RV or tiny home during construction; ask Planning & Community Development before you plan on it.10

Building a home in Bainbridge Island: the steps, in order

  1. Confirm your lot's zoning district and any shoreline or critical-area overlay with PCD at 206-780-3750.101
  2. If the lot is not on public sewer, hire a licensed septic designer and take the project to the Kitsap Public Health District.1817
  3. Prepare and submit the application packet through the city's public permit portal.11
  4. Expect land use, fire and development engineering review alongside the building department.11
  5. Pay the fees calculated at payment and schedule inspections.12

What stays with Kitsap County, and what to check before you buy

Septic permits stay with the Kitsap Public Health District even inside city limits.3 For land outside the city, Kitsap County's own department handles building permits and zoning; see the Kitsap County page for those rules.

Before buying, confirm the zoning district and lot size, whether public sewer reaches the parcel, and whether shoreline or critical-area overlays apply.113 Kitsap County's effective property tax rate is 0.8%, with a median bill of $4,030 a year.1920

Watch-outs

  • We could not confirm Bainbridge Island's general building-permit exemptions, certificate of occupancy, owner-builder, well, driveway or floodplain rules; ask Planning & Community Development at 206-780-3750.10
  • Septic approval is separate from the city's building permit and comes from the Kitsap Public Health District.3
  • ADUs cannot be used as short-term rentals without an approved business license.5

Sources

  1. Chapter 18.12 Dimensional Standards - City of Bainbridge Island, WA (eCode360) (Bainbridge Island), quoted and re-checked
  2. City of Bainbridge Island Pre-Approved ADU Plans Overview (Bainbridge Island), quoted and re-checked
  3. City of Bainbridge Island Pre-Approved ADU Plans Overview (Bainbridge Island), quoted and re-checked
  4. City of Bainbridge Island Pre-Approved ADU Plans Overview (Bainbridge Island), quoted and re-checked
  5. City of Bainbridge Island Pre-Approved ADU Plans Overview (Bainbridge Island), quoted and re-checked
  6. Chapter 18.12 Dimensional Standards - City of Bainbridge Island, WA (eCode360) (Bainbridge Island), quoted and re-checked
  7. Chapter 18.12 Dimensional Standards - City of Bainbridge Island, WA (eCode360) (Bainbridge Island), quoted and re-checked
  8. Chapter 18.12 Dimensional Standards - City of Bainbridge Island, WA (eCode360) (Bainbridge Island), quoted and re-checked
  9. Chapter 18.12 Dimensional Standards - City of Bainbridge Island, WA (eCode360) (Bainbridge Island), quoted and re-checked
  10. City of Bainbridge Island Planning & Community Development (bainbridgewa.gov)
  11. City of Bainbridge Island Pre-Approved ADU Plans Overview (Bainbridge Island), quoted and re-checked
  12. City of Bainbridge Island Pre-Approved ADU Plans Overview (Bainbridge Island), quoted and re-checked
  13. City of Bainbridge Island Pre-Approved ADU Plans Overview (Bainbridge Island), quoted and re-checked
  14. Septic System Construction, Repairs & Maintenance, quoted and re-checked
  15. Septic System Construction, Repairs & Maintenance, quoted and re-checked
  16. WAC 246-272A-0200 Permit requirements (Washington statewide rule), quoted and re-checked
  17. Kitsap Public Health District (kitsappublichealth.org)
  18. Residential Building Clearances, quoted and re-checked
  19. Effective property tax rate: Bolthole Index county data
  20. Median property tax bill: Bolthole Index county data

Written October 14, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.

Answers from the rulebook for Bainbridge Island

Bainbridge Island’s own rules

  • Building permitRequired

    Accessory dwelling unit construction inside Bainbridge Island city; permit issued by city Planning & Community Development

    • Evidence is specific to ADUs; general new-home permit rule not opened
    “the owner or applicant must apply for an adu building permit with the city of bainbridge island planning & community development (pcd).”
  • Local zoningPresent

    Land inside Bainbridge Island city limits; the city adopts and administers its own zoning (BIMC Title 18)

    • Shoreline, critical areas and other overlays may add requirements
    “all development in the city of bainbridge island shall be subject to the dimensional standards in tables 17.12.070-1, 18.12.020-2 and 18.12.020-3 and bimc § 18.12.030”
  • Zoning districtsPublished

    Residential zone districts inside Bainbridge Island city

    • Mixed use town center and other districts are in Table 18.12.020-3
    “zoning district dimensional standard r-0.4 r-1 r-2 r-2.9 r-3.5 r-4.3 r-5 r-6 r-8 r-14”
  • Minimum lot sizeDistrict specific (with conditions)

    Standard lots in residential zone districts R-0.4 through R-14 inside Bainbridge Island city; R-2 is 20,000 sq ft

    • Flexible lot subdivision options in BIMC 17.12.030 may change lot dimensions
    • Existing approved lots may be nonconforming

    minimum lot area R-0.4: >= 100000 sq ft · minimum lot area R-1: >= 40000 sq ft · minimum lot area R-2: >= 20000 sq ft · minimum lot area R-2.9: >= 15000 sq ft · minimum lot area R-3.5: >= 12500 sq ft · minimum lot area R-4.3: >= 10000 sq ft · minimum lot area R-5: >= 8500 sq ft · minimum lot area R-6: >= 7260 sq ft · minimum lot area R-8: >= 5400 sq ft · minimum lot area R-14: >= 3100 sq ft

    “standard lots 100,000 sq. ft. 40,000 sq. ft. 20,000 sq. ft. 15,000 sq. ft. 12,500 sq. ft. 10,000 sq. ft. 8,500 sq. ft. 7,260 sq. ft. 5,400 sq. ft. 3,100 sq. ft.”
  • Lot coverageDistrict specific (with conditions)

    Standard lots in residential zone districts R-0.4 through R-14 inside Bainbridge Island city; R-2 base is 20%

    • Bonus coverage of 40% or 50% available under BIMC 18.12.030.a and .b in R-8 and R-14

    maximum lot coverage R-0.4: <= 10 percent · maximum lot coverage R-1: <= 15 percent · maximum lot coverage R-2: <= 20 percent · maximum lot coverage R-2.9 to R-5: <= 25 percent

    “standard lots base 10% 15% 20% 25% 25% 25% 25% n/a 25% 40%”
  • Accessory dwellingsLimited

    Accessory dwelling units on single-family lots inside Bainbridge Island city

    • Permitted per BIMC 18.09.030, or conditional in shoreline jurisdiction under BIMC 16.12
    • One ADU per parcel
    • Maximum 1,000 sq ft with stated exceptions
    • No recreation vehicle may be an ADU
    • Detached ADUs must meet zone setback and lot coverage standards
    • One off-street parking space unless within 0.25 miles of transit or sufficient on-street parking
    • Not for short-term rental without approved business license

    maximum ADU size: <= 1000 sq ft (larger allowed within buildings existing at ordinance 201526; garage area not counted) · ADUs per parcel: <= 1

    “an adu may be created within or detached from any single-family dwelling, whether existing or new, as a subordinate use”
  • Mandatory utility hookupConditional

    Accessory dwelling units inside Bainbridge Island city

    • Connection required only where public sewer and water are available
    • Septic needs Kitsap Public Health District approval
    • General new-home rule in BIMC 13.12.010 not read
    “must connect to public sewer and water where available. if using a septic system, approval from the kitsap public health district is required.”
  • Subdividing landRegulated (with conditions)

    Subdivision and resubdivision of lots inside Bainbridge Island city

    • Flexible lot design requirements (BIMC 17.12.030) apply
    “any future resubdivision of any such lots shall comply with adopted flexible lot design requirements.”
  • Short-term rentalsLimited

    Accessory dwelling units used as short-term rentals inside Bainbridge Island city

    • Requires an approved business license for that use
    • General short-term rental rules not opened
    “adus cannot be used for short-term rentals (e.g., airbnb) unless an approved business license is obtained for that use.”
  • Permit feesVariable (with conditions)

    Permit fees for ADU building permits inside Bainbridge Island city

    • Final fees are calculated at payment; fee schedule not opened
    “additional fees will be required as part of the permitting process. the fees cover the costs of reviewing applications, permits, and inspections.”
  • Permit processPartial

    ADU permit application inside Bainbridge Island city

    • Land use, fire and development engineering review in addition to building department
    “contact pcd to evaluate project site & requirements prepare and submit application packet via the public permit portal”

Rules another office applies inside Bainbridge Island

Bainbridge Island does not set these itself; the county, a health district or the state does, and they apply to every address inside its limits.

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Bainbridge Island or Kitsap County directly.

  • Owner-builder exemption — Owner-builder exemption inside Bainbridge Island city
  • Building code adopted — Building code adoption inside Bainbridge Island city
  • Inspections — Building inspections inside Bainbridge Island city
  • Certificate of occupancy — Certificate of occupancy inside Bainbridge Island city
  • Minimum dwelling size — Minimum dwelling size inside Bainbridge Island city
10 more unanswered
  • Living in an RV
  • Camping on your land
  • Tiny homes
  • Manufactured homes
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Agricultural exemption
  • Driveway access
  • Building in a floodplain

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Unanswered questions are usually a sign that Bainbridge Island publishes no rule on the point, not that none exists. Kitsap County’s page lists the county offices to call.

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