Bolthole Index

San Juan County, Washington

Building permits, zoning and land rules in San Juan County, Washington

55Index Score / 100
#20 of 39 in Washington

Unincorporated San Juan County, Washington requires a building permit for construction, issued by the Department of Community Development and filed online through the SJC Permit Center12. Zoning is county-run under the Unified Development Code, with standards that vary by district and subarea plan34. Septic and water-availability applications go separately to Health & Community Services5.

At a glance

Building permit
Required for construction in unincorporated San Juan County; confirm exemptions with Community Development6
Zoning
Yes; standards vary by zoning district and subarea plan47
Septic permit
Required; handled by county Health & Community Services85
Owner-builder
A contractor-registration exemption may apply, but permits still do9
RV living
Private-land occupancy rule not confirmed; ask Community Development10
Tiny home
Must meet the state building code; local location and installation approval still applies11
Minimum dwelling size
State code sets interior-space minimums; county zoning may add parcel-specific limits1210
County-road driveway
County permission is required before constructing an approach13

Who to call

Building permits

San Juan County Department of Community Development

Building permits and inspections, code enforcement, land-use designations and planning in San Juan County

360-378-2354

135 Rhone Street, Friday Harbor, WA 98250

Online permits →

Septic permits

San Juan County Health & Community Services

Sewage-disposal-system and water-availability applications for San Juan County

360-378-4474

PO Box 607, Friday Harbor, WA 98250

Roads & driveways

San Juan County Public Works

Questions about work and driveway access in county road rights-of-way

360-370-0500

pubwks@sanjuancountywa.gov

1609 Beaverton Valley Rd, Friday Harbor, WA 98250

Contact details are copied from each office’s official page and were checked against it on October 10, 2026.

Off-grid gear

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

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Do you need a building permit in San Juan County, Washington?

San Juan County requires building permits for construction, alteration and repair in the unincorporated county through the Department of Community Development; the county building code applies within unincorporated San Juan County6. The county Building Department administers the state-adopted building, residential, mechanical, plumbing, fuel-gas, energy, indoor-air-quality and ventilation codes14. Accessory structures typically defined as Group M1 or M2 may qualify for a statement of exemption when they are accessory to a private residence or used for agriculture and are not used for human habitation6. The county’s published material does not provide a complete exemption list, so ask Community Development whether a particular shed, repair or other scope needs a permit15. Sewage-disposal and water-availability applications go separately to Health & Community Services with the appropriate fee6. Required life-safety inspections are requested through the Permit Center or the inspection hotline16. Every new-construction project requires a certificate of occupancy after all items pass final inspection; stand-alone mechanical or plumbing work and repairs do not17. An owner-builder building permit costs 57.5% of the conventional fee, with a $69 minimum, and building permits and inspections still apply18.

Who is the San Juan County building department, and how do you apply?

The San Juan County Department of Community Development handles building permits and inspections, code enforcement, land-use designations and planning15. The office is at 135 Rhone Street in Friday Harbor, and its phone number is 360-378-235415. File building-permit applications online through the SJC Permit Center after preparing recent water-availability and sewage records, a site plan and construction drawings2. Plumbing and mechanical routing and termination plans are required for all permits beginning May 1, 20252. Published conventional building-permit fees are valuation-based with a $69 minimum, and conventional plan review is 65% of the building-permit fee19.

Does San Juan County have zoning?

San Juan County has zoning, with most land-use standards and permit requirements in Title 16 and Title 18, the Unified Development Code20. The Unified Development Code regulates current and proposed land use, infrastructure and facilities3. Rules vary among county zoning districts and distinct subarea plans, including the listed planning areas for Eastsound, Lopez Village, Deer Harbor, Doe Bay/Westsound, Olga, Orcas Village, Shaw Island and Waldron Island47. Setbacks fall under Chapter 18.60 of the county code: outside activity centers and urban growth areas, road setbacks are measured from the centerline of the existing road rather than the right-of-way edge, and side and rear setbacks are measured from the property edge21. Building height and lot coverage are set by district, and approved subarea plans may set different heights in rural districts2223. We could not confirm a single minimum lot size, so a parcel’s allowed use and dimensional standards require a parcel-specific check. Dividing land is regulated separately under the Unified Development Code24. Community Development handles land-use designations and planning, so confirm the designation and applicable standards before relying on a listing or a neighboring property15.

How do septic permits work in San Juan County?

San Juan County Health & Community Services administers on-site sewage systems where municipal treatment is unavailable and assists with siting, design, installation, operation and maintenance8. Submit sewage-disposal and water-availability applications directly to that department with the appropriate fee5. After installation, gravity systems need inspection every three years unless they are in a designated sensitive area; pressure, sand-filter, mound, aerobic-treatment and sensitive-area gravity systems need annual inspection25. A licensed wastewater inspector or county-trained certified homeowner must perform the inspection25. Because 0% of mapped county soils are rated free of severe limitations for a conventional drain field, make site evaluation and system design early purchase contingencies26.

Can you live in an RV or tiny home on your land in San Juan County?

We could not confirm a San Juan County rule that generally allows RV occupancy on private land. The one county rule we found is narrow: a mobile home park may have an RV storage area for residents' RVs, with no utility hookups, and no RV in that storage area may be used as living quarters27. So ask Community Development about the parcel, duration and utility arrangement before moving an RV onto a site15. Washington’s statutory RV definition in the manufactured-home context describes an RV as temporary, transient quarters that are not a primary residence, but that definition does not create general permission to live in one on private land28. A Washington tiny house may be built on wheels and may be no larger than 400 square feet, but it must meet the state building code and still needs local approval for its foundation, installation and location11. A new detached accessory dwelling outside urban growth areas and activity centers must first win an eligibility number through the county ADU lottery, and cannot be separately leased for less than 30 days29.

Building a home in San Juan County: the steps, in order

  1. Ask Community Development to identify the parcel’s zoning district or subarea plan and the standards governing the home415.
  2. Start sewage-disposal and water-availability review with Health & Community Services5.
  3. Prepare recent water and sewage records, a site plan, construction drawings, and the required plumbing and mechanical routing plans2.
  4. Submit the building-permit application online through the SJC Permit Center2.
  5. If the property needs a new detached accessory dwelling, obtain an ADU eligibility number before applying29.
  6. If acting as your own contractor, confirm that the contractor-registration exemption fits; it does not waive permits and excludes work for sale, demolition or lease9.
  7. Complete required inspections and obtain the certificate of occupancy after all items pass final inspection17.

What should you check before buying land in San Juan County?

Make septic feasibility a purchase contingency because 0% of mapped San Juan County soils are rated free of severe limitations for a conventional drain field26. Confirm legal water availability with Health & Community Services, since the county routes water-availability applications to that department alongside sewage paperwork3031. Review floodplain status and road access before choosing a homesite, because floodplain development needs a local permit and a new county-road approach needs county permission3213. The county averages 28.8 inches of precipitation annually, while 71.3% of its land is at a slope of 15% or less3334. The effective property-tax rate is about 0.6%, and the median annual property-tax bill is about $4,1313536.

Watch-outs

  • San Juan County does not publish a complete permit-exemption list in the material summarized here, so confirm a small or unusual project with Community Development before treating it as exempt15.
  • The contractor-registration exemption for work on your own property does not waive building, septic, electrical, plumbing or other approvals9.
  • A tiny house that meets Washington’s size and code definition still needs local approval for foundation, installation and location11.

Sources

  1. Chapter 15.04: Construction Codes Adopted (2026 county census)
  2. Building Permit Forms and Information, quoted and re-checked
  3. Long Range Planning, quoted and re-checked
  4. Land Use, quoted and re-checked
  5. Building Permit Forms and Information, quoted and re-checked
  6. Chapter 15.04: Construction Codes Adopted, quoted and re-checked
  7. Land Use, quoted and re-checked
  8. On-Site Sewage Program, quoted and re-checked
  9. RCW 18.27.090 — Exemptions, quoted and re-checked
  10. Long Range Planning (2026 county census)
  11. Tiny Houses (Washington statewide rule), quoted and re-checked
  12. WAC 51-50-1208 — Section 1208—Interior space dimensions (Washington statewide rule), quoted and re-checked
  13. RCW 36.75.130 — Approaches to county roads—Rules regarding construction—Penalty (Washington statewide rule), quoted and re-checked
  14. Building, quoted and re-checked
  15. San Juan County Department of Community Development (sanjuancountywa.gov)
  16. Building, quoted and re-checked
  17. Electronic permitting requirements and instruction for application, quoted and re-checked
  18. Fee Schedule, quoted and re-checked
  19. Fee Schedule, quoted and re-checked
  20. Land Use, quoted and re-checked
  21. San Juan County Code Chapter 18.60, quoted and re-checked
  22. San Juan County Code Chapter 18.60, quoted and re-checked
  23. sanjuancountywa.gov, quoted and re-checked
  24. Land Division – Application for Preliminary Approval, quoted and re-checked
  25. On-Site Sewage Program, quoted and re-checked
  26. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
  27. Chapter 18.40: Performance and Use-Specific Standards, quoted and re-checked
  28. app.leg.wa.gov (Washington statewide rule), quoted and re-checked
  29. Accessory Dwelling Units, quoted and re-checked
  30. Applying for a Permit, quoted and re-checked
  31. San Juan County Health & Community Services (sanjuancountywa.gov)
  32. Planning & regulation — Washington State Department of Ecology (Washington statewide rule), quoted and re-checked
  33. Annual precipitation: Bolthole Index county data
  34. Share of land at 15% slope or less: Bolthole Index county data
  35. Effective property tax rate: Bolthole Index county data
  36. Median property tax bill: Bolthole Index county data

Written October 10, 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.

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Compared with neighboring counties

Like all 6 of its neighbors, San Juan County has countywide zoning.

RuleSan Juan CountyIsland CountySkagit CountyWhatcom CountyClallam CountyJefferson CountyKitsap County
Building permitRequiredRequiredRequiredRequiredRequiredRequiredLimited
County zoningYesYesYesYesYesYesYes
Septic permitsCounty Health & Community ServicesCounty Public HealthCounty Public HealthCounty Health & Community ServicesCounty Env. Health ServicesCounty Public HealthKitsap Public Health District

County locator

San Juan County in Washington

55
County map
San Juan County highlighted among the Washington counties · colored by Index score

How San Juan County scores

Seclusion4246% ev.
Self-Sufficiency52100% ev.
Admin Boringness41100% ev.
Durability56100% ev.
Property Autonomy50100% ev.
Carry Cost43100% ev.

Evidence strength: 88%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$888kTypical home
0.6%Property tax
$12,320Land / acre
28.8"Annual rain
5.6% of yrsSevere drought
0 / yr (+0)Mid-century 100°F days
21.4 daysMid-century dry spell
1.12" (+9%)Mid-century 1-day rain
1.59×Wildfire change factor
100%Forward climate coverage
$2,398Home insurance / yr
1.4% / yrInsurance growth
1.02%Nonrenewal rate
county median (2+ published ZIPs)Insurance basis
3,212People within 30 min
13,651Radius comparison (15 mi)
106.8People / sq mi
71.3%Land at 15% slope or less
0%Soils rated "not limited" for septic (strict USDA rating)
0 acWorkable land screen
38.8%Wooded land
138.3 tonsBiomass / forest ac
50.8°FAvg temp

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Cities and towns in San Juan County

Inside a city or town, that city usually issues building permits and sets zoning; the county’s rules above cover unincorporated land. Septic, wells and floodplain rules usually stay with the county or state everywhere.

Answers from the rulebook for San Juan County

What the ordinances and state agencies actually say — one answer per question, each quoted from the official source and independently re-checked.

San Juan County rules

  • Building permitRequired

    Construction, alteration, or repair subject to the San Juan County building code in unincorporated San Juan County.

    • The county code states that the building-code article applies within unincorporated San Juan County.
    • Owner-built residences and appurtenant structures use the owner/builder permit process.
    • Accessory structures typically defined as Group M1 or M2 may qualify for a statement of exemption when accessory to a private residence or used for agricultural purposes, provided they are not used for human habitation.
    • Separate sewage-disposal and water-availability applications must be submitted directly to Health & Community Services with the appropriate fee.
    “The requirements of this article apply within unincorporated San Juan County.”
  • Owner-builder exemptionAvailable (with conditions)

    Owner-builder building permits in San Juan County.

    • The county fee schedule provides a separate owner-builder permit and plan-review fee structure.
    • Building permits and inspections remain applicable.

    owner builder building permit: 57.5% of conventional fee ($69 minimum) · owner builder plan review: 75% of conventional plan review fee · annual renewal fee: 56 USD/year

    “Owner Builder Building Permit 57.5% of Conventional Fee ($69 minimum)”
  • Building code adoptedAdopted (with conditions)

    Building construction regulated by the San Juan County Building Division.

    • The county states that construction must meet the minimum standards of building codes in effect in San Juan County.
    “They are responsible for ensuring that building construction meets the minimum standards of the building codes in effect in San Juan County.”
  • InspectionsRequired

    Construction under San Juan County building permits.

    • The county page refers to required life-safety inspections under new permits.
    • Inspections are requested through the Permit Center or inspection hotline and are unavailable on holidays.
    “all required life safety inspections under new permits”
  • Certificate of occupancyLimited

    Completion of permitted building construction where the county issues a certificate of occupancy.

    • The county states that construction is complete as evidenced by issuance of a certificate of occupancy.
    • The fee schedule separately lists a temporary certificate of occupancy.

    temporary certificate of occupancy fee: 222 USD

    “not complete as evidenced by the issuance of a certificate of occupancy”
    One more reviewed finding on this topic
    • Required — New construction projects in unincorporated San Juan County.
      “All new construction projects require a Certificate of Occupancy. Stand alone Mechanical/plumbing, and repairs do not. Certificate of Occupancy is granted only after all items have passed final inspection.”
  • County-wide zoningPresent

    San Juan County land-use regulation through the County Unified Development Code.

    • The source describes the UDC as county law regulating current and proposed land use, infrastructure, and facilities.
    “The Unified Development Code (UDC). The Land Use Code, often referred to as zoning, implements the policies developed in the Plan by making them part of the County laws regulating current and proposed land use, infrastructure and facilities.”
    One more reviewed finding on this topic
    • Present (with conditions) — County zoning and land-use regulation in unincorporated San Juan County.
      “San Juan County Code contains standards and permit requirements for property development in the County. Most land use regulations are in Title 16, Land Use and Development, or Title 18 also referred to as the Unified Development Code (UDC).”
  • Local zoningPresent (with conditions)

    County land-use zoning administered through San Juan County's Unified Development Code.

    • The county page identifies the Unified Development Code land-use code as zoning and states that it regulates current and proposed land use, infrastructure, and facilities.
    • The cited statement addresses county laws and does not establish that incorporated municipalities administer identical county zoning rules.
    “The Unified Development Code (UDC). The Land Use Code, often referred to as zoning, implements the policies developed in the Plan by making them part of the County laws regulating current and proposed land use, infrastructure and facilities.”
    One more reviewed finding on this topic
    • Varies (with conditions) — Aggregate local zoning across county-administered unincorporated areas and distinct subarea plans.
      “Most land use regulations are in Title 16, Land Use and Development, or Title 18 also referred to as the Unified Development Code (UDC).”
  • Zoning districtsPublished (with conditions)

    County zoning and subarea-plan districts in unincorporated San Juan County.

    • District-specific standards may be located in Title 16, Title 18, or listed subarea plans.
    • The county page lists Eastsound, Lopez Village, Deer Harbor, Doe Bay/Westsound, Olga, Orcas Village, Shaw Island, and Waldron Island planning areas.
    “Fairgrounds Overlay District (SJCC 18.35.155)”
  • SetbacksSpecified

    Setbacks under SJCC Chapter 18.60, varying by activity center, UGA, rural, resource, and special land-use district.

    • Setbacks from roads in activity centers or UGAs are measured from the road right-of-way margin line.
    • Outside activity centers or UGAs, road setbacks are measured from the centerline of the existing road.
    • Side and rear setbacks are measured from the property edge.
    • Exceptions include fences in specified circumstances, mailboxes, wells, pump houses, bus shelters, septic systems, drainfields, landscaping, and utility apparatus.
    • Road right-of-way setbacks may be waived at the county engineer's discretion in stated circumstances.
    “Setbacks from roads in activity centers or urban growth areas shall be measured from the margin line of the road right-of-way. Setbacks outside of activity centers or urban growth areas are measured from the centerline of the existing road.”
  • Lot coverageSpecified

    Maximum lot coverage and related impervious-surface standards in applicable county land-use districts.

    • Maximum lot coverage is measured by the percentage of total surface area occupied by structures, with stated exclusions for roof overhangs and covered porches not used for sales, storage, or service.
    • RFF districts have a stated 30 percent impervious-surface limit excluding roads and driveways.

    RFF impervious surface maximum: 30 percent (exclusive of roads and driveways)

    ““Maximum lot coverage” is measured by the percentage”
  • Building heightDistrict specific (with conditions)

    Building-height standards under county land-use districts and approved subarea plans.

    • Specified appurtenances are exempt from height requirements.
    • Structures used for agricultural-material storage are exempt from maximum building-height requirements.
    • Approved subarea plans may establish different height requirements in rural districts.
    “Chimneys, smokestacks, fire or parapet walls, ADA-required elevator shafts, flagpoles, utility lines and poles, skylights, communication sending and receiving devices, HVAC and similar equipment, and spires associated with places of worship are exempt from height requirements.”
  • Living in an RVLimited

    Recreational vehicles stored in a mobile home park in unincorporated San Juan County.

    • The storage area must be for recreational vehicles owned by residents of the park.
    • The storage area may not contain utility hookups.
    • An RV in the storage area may not be used as living quarters.
    • This provision addresses RV storage within mobile home parks and does not establish a general countywide rule for all RV occupancy situations.
    “A mobile home park may include a storage area for recreational vehicles owned by residents of the park; provided, that the storage area contains no utility hook-ups and that no RV within the storage area shall be used as living quarters.”
  • Accessory dwellingsLimited

    New detached accessory dwelling units outside urban growth areas and activity centers.

    • An ADU eligibility number is required before permit application.
    • A site plan and development application must conform to SJCC 18.40.240 and standard building permit requirements.
    • New detached ADUs outside UGAs and activity centers require the county ADU Lottery process.
    • Detached ADUs established under SJCC 18.40.240 cannot be separately leased or rented for less than 30 days; detached ADUs constructed after June 29, 2007 cannot be used for vacation rentals.

    ADU lottery application fee: 245 USD (2026 eligibility application period)

    “require first going through an ADU Lottery process to determine eligibility for a new ADU permit.”
  • Who permits septicCounty (with conditions)

    On-site sewage systems in San Juan County areas not served by municipal sewage treatment plants.

    • The county program provides technical assistance on siting, design, installation, operation, and maintenance.
    • The program applies to areas not served by municipal sewage treatment plants.
    “Our on-site sewage program provides services to help ensure safe treatment and disposal of wastewater”
    One more reviewed finding on this topic
    • County — On-site sewage administration in areas of San Juan County not served by municipal sewage treatment plants.
      “Our on-site sewage program provides services to help ensure safe treatment and disposal of wastewater in areas of San Juan County not served by municipal sewage treatment plants.”
  • Septic permitRequired

    Sewage disposal system applications administered by San Juan County Health & Community Services.

    • Applications must be submitted directly to Health & Community Services.
    • The source states that the appropriate fee must accompany the application.
    • The page identifies the mailing address as PO Box 607, Friday Harbor, WA 98250.
    “Sewage disposal system and water availability applications must be submitted directly to Health & Community Services, with the appropriate fee, at PO Box 607, Friday Harbor, WA 98250.”
  • Septic inspectionRequired

    On-site sewage systems in areas of San Juan County not served by municipal sewage treatment plants.

    • Property owners are required to have their systems inspected on a periodic basis beginning in 2009.
    • Inspections must be completed by either a licensed wastewater inspector or a certified homeowner who attended a homeowner training class presented by San Juan County Health & Community Services.
    • Gravity systems must be inspected every three years unless located in a designated sensitive area, usually areas surrounding commercial shellfish growing enterprises.
    • All other systems, including pressure systems, sand filters, mound systems, gravity systems in designated sensitive areas, and aerobic treatment systems, require annual inspection.
    • Effective in 2014, the inspection report filing fee was replaced by a $10 fee collected with property tax on parcels with septic systems.

    gravity system inspection interval: 3 years (unless located in a designated sensitive area) · other covered system inspection interval: 1 year (includes pressure systems, sand filters, mound systems, gravity systems in designated sensitive areas, and aerobic treatment systems) · on-site sewage system inspection report fee: 10 USD (collected with property tax on parcels that have septic systems; effective in 2014)

    “Gravity systems need to be inspected every three years unless located in a designated sensitive area (usually areas surrounding commercial shellfish growing enterprises). All other systems that include but not limited to pressure systems, sand filters, mound systems, gravity systems located in designated sensitive areas and aerobic treatment systems are required to be inspected on an annual basis.”
    2 more reviewed findings on this topic
    • Required — On-site sewage systems in San Juan County, including systems outside municipal sewage-treatment areas.
      “Gravity systems need to be inspected every three years unless located in a designated sensitive area (usually areas surrounding commercial shellfish growing enterprises). All other systems that include but not limited to pressure systems, sand filters, mound systems, gravity systems located in designated sensitive areas and aerobic treatment systems are required to be inspected on an annual basis.”
    • Required — On-site sewage systems in San Juan County.
      “property owners are required to have their system inspected on a periodic basis beginning in 2009.”
  • Subdividing landRegulated (with conditions)

    Property divisions, short subdivisions, and long subdivisions processed under San Juan County's Unified Development Code.

    • The county requires an approval process to ensure compatibility with the Comprehensive Plan, UDC regulations, and Chapter 58.17 RCW.
    • A simple land division may divide a parcel into two lots, each greater than five acres, when the original tract and adjacent same-owner property have been unchanged for five years; a separate application packet is required.
    • Short subdivisions create four or fewer lots and are limited to unplatted land or land previously divided by a short subdivision that has not been divided for five years or more from recording of the original short subdivision.
    • Long subdivisions create five or more lots or divide into two or more parcels where the land was divided less than five years before the application.
    • For short subdivisions and subdivisions, CD&P has 28 days to determine completeness after submission of the application and applicable fees; if incomplete, the applicant has 90 days to provide missing information.
    • Approval criteria include SJCC 18.70.050 and 18.70.060, applicable Chapter 18.60 standards, Chapter 58.17 RCW, the Shoreline Master Program, applicable subarea plan, SEPA, and the Comprehensive Plan; required shoreline-permit action must be completed for subdivision improvements.
    • The current fee schedule must be checked online or obtained from CD&P.

    simple land division resulting lots: 2 lots (each lot must be greater than five acres; original tract and adjacent same-owner property unchanged for five years) · short subdivision lot count: <= 4 lots (land must satisfy the stated unplatted or five-year prior-division condition) · long subdivision lot count: >= 5 lots (also covers two or more parcels where land was previously divided less than five years before application) · application completeness determination: 28 days (after application and applicable fees are submitted) · missing-information response period: 90 days (for an incomplete application)

    “The San Juan County Unified Development Code (UDC) establishes several methods to divide property, two of which utilize this application packet. The purpose for requiring an approval process to divide property is to ensure that the proposed use is compatible with the policies of the San Juan County Comprehensive Plan, the regulations of the UDC, and the requirements of the State Subdivision Act, Chapter 58.17 RCW.”
    One more reviewed finding on this topic
    • Regulated (with conditions) — Parcel divisions and land divisions in San Juan County.
      “Examples of land use projects are parcel divisions”
  • Permit feesPublished

    San Juan County building, plan-review, owner-builder, inspection, manufactured-home, modular, plumbing, mechanical, and vacation-rental-related fees.

    • The fee schedule is subject to amendment by later resolutions or ordinances.
    • The schedule identifies Resolution No. 34-2020 and Resolution No. 43-2019 as amendments to the schedule adopted via Resolution No. 62-2016.

    conventional building permit minimum: >= 69 USD (based on valuation) · conventional plan review: 65 percent of building permit fee · owner-builder building permit: 57.5 percent of conventional fee ($69 minimum) · owner-builder plan review: 75 percent of conventional plan review fee · annual renewal fee: 56 USD/year · subsequent life-safety inspection for sale, lease, or rental: 111 USD · mobile/manufactured home permit: 222 USD/unit · temporary certificate of occupancy: 222 USD

    “PER SAN JUAN COUNTY RESOLUTION NO. 62-2016 BUILDING FEES SERVICE FEE Conventional Building Permit Based on Valuation* per attached table ($69 minimum) Conventional Plan Review 65% of Building Permit Fee** Annual Renewal Fee $56.00/year Owner Builder Building Permit 57.5% of Conventional Fee ($69 minimum)”
    One more reviewed finding on this topic
    • Published (with conditions) — County building, planning, land-use, subdivision, owner-builder, occupancy, and related permit fees.
      “Conventional Building Permit Based on Valuation* per attached table ($69 minimum) [...] Owner Builder Building Permit 57.5% of Conventional Fee ($69 minimum) [...] Temporary Certificate of Occupancy $222.00”
  • Permit processPublished (with conditions)

    Building permit submission and related sewage and water-availability applications.

    • Building permit applications are submitted through the SJC Permit Center.
    • Paper plans or applications are not accepted for building permits.
    • Sewage disposal and water availability applications are submitted directly to Health & Community Services with the appropriate fee.
    • Fees become due after submittal documents are reviewed for completeness, within 21 days prior to formal review.
    “All Building permit applications are submitted via the SJC Permit Center.”
    One more reviewed finding on this topic
    • Published (with conditions) — Building-permit application and review process in unincorporated San Juan County.
      “Building permit applications are submitted online in the SJC Permit Center. Preparing all supporting documentation (such as recent water availability and sewage system records, a site plan, or construction drawings) is recommended before applying. Beginning May 1, 2025: Plans for plumbing and mechanical routing/termination will be required for all permits.”

Washington rules that apply here

  • Minimum dwelling sizeSpecified

    Dwelling units regulated by Washington's state building code.

    • The rule specifies habitable-space and room-area minimums, not a zoning minimum lot or gross floor-area standard.
    • Kitchens are expressly excepted from the minimum floor-area requirement.
    • Efficiency dwelling units must comply with Sections 1208.1 through 1208.4 and must have a separate closet, required kitchen facilities, light and ventilation, and a separate bathroom as stated in the source.
    • The current rule text states WSR 23-23-102 was filed 11/15/23 and effective 3/16/24.

    minimum habitable space: >= 190 square feet · minimum area of at least one room: >= 120 square feet · minimum net floor area of sleeping units and other habitable rooms: >= 70 square feet (Kitchens are not required to be of a minimum floor area.)

    “1208.3 Dwelling unit size. Dwelling units shall have a minimum of 190 square feet (17.7 m 2) of habitable space. 1208.4 Room area. Every dwelling unit shall have not less than one room that shall have not less than 120 square feet (11.2 m 2) of net floor area. Sleeping units and other habitable rooms of a dwelling unit shall have a net floor area of not less than 70 square feet (6.5 m 2). EXCEPTION: Kitchens are not required to be of a minimum floor area.”
  • Tiny homesAllowed (with conditions)

    Occupancy and placement of tiny houses in Washington

    • A tiny house may be built on wheels and may not exceed 400 square feet including kitchen, bathroom, and sleeping/living area.
    • It must be built to the Washington State Building Code.
    • Approval depends on where it is built; local building-department requirements and permits apply to foundation, installation, and location.
    • A wheeled structure that is not a tiny house as described may instead be a recreational vehicle or park model.
    • A manufactured home, including a tiny manufactured home, requires consultation with the local building department regarding where it may be located.

    maximum area: <= 400 square feet

    “A tiny house is a dwelling that may be built on wheels and is no larger than 400 square feet, including a kitchen, bathroom, and sleeping/living area, and must be built to the Washington State Building Code. The approval process for a tiny house depends on where it's built.”
  • Manufactured homesLimited

    State statutory limits on county regulation of the placement or use of HUD-standard manufactured homes in Washington; site-specific occupancy remains subject to applicable local and state requirements.

    • The nondiscrimination and equal-siting rule applies to homes built to 42 U.S.C. Sec. 5401-5403 standards, as amended in 2000.
    • Except as provided in RCW 36.01.225(2), a county may require that a manufactured home be new.
    • Except as provided in RCW 36.01.225(2), a county may require a permanent foundation specified by the manufacturer and enclosure of the space from the bottom of the home to the ground with concrete or an approved concrete product, load bearing or decorative.
    • Except as provided in RCW 36.01.225(2), a county may require compliance with local design standards applicable to all other homes in the neighborhood.
    • Except as provided in RCW 36.01.225(2), a county may require thermal equivalence to the state energy code and all other requirements for a designated manufactured home under RCW 35.63.160.
    • A county may not restrict location in a manufactured/mobile home community legally in existence before June 12, 2008, based exclusively on the manufactured/mobile home's age or dimensions.
    • A county may not prohibit siting on an existing lot solely because existing separation and setback requirements regulating distance between homes are unmet.
    • A county may restrict location in a manufactured/mobile home community for other reasons, including failure to comply with fire, safety, other local ordinances, or state laws related to manufactured/mobile homes.
    • The statute does not override legally recorded covenants or deed restrictions of record and does not affect authority granted under chapter 43.22 RCW.

    community legal-existence date for age-or-dimensions protection: 2008-06-12 (Applies to manufactured/mobile home communities legally in existence before this date.)

    “A county may not adopt an ordinance that has the effect, directly or indirectly, of discriminating against consumers' choices in the placement or use of a home in such a manner that is not equally applicable to all homes. Homes built to 42 U.S.C. Sec. 5401-5403 standards (as amended in 2000) must be regulated for the purposes of siting in the same manner as site built homes, factory built homes, or homes built to any other state construction or local design standard.”
  • Well permitLimited

    Groundwater wells and groundwater uses statewide under Washington's water-right permit exemption.

    • Domestic use is exempt up to 5,000 gallons per day.
    • Industrial use is exempt up to 5,000 gallons per day.
    • Lawn or garden irrigation is exempt only for a half-acre or less.
    • Stockwater is exempt.
    • Only one permit-exempt use of each type is allowed for any one project, regardless of project size.
    • Withdrawals from multiple wells for one project are aggregated toward the exemption limits.
    • Local governments and other laws and rules may impose additional requirements and limits.
    • Use in excess of the listed amounts, use for other purposes, or use from a surface-water source requires applying for and receiving a water-right permit.
    • Before drilling, a notice of intent must be submitted to Ecology 72 hours before drilling starts; the NOI is not itself a permit or approval to use water.
    • Permit-exempt uses remain subject to state water law, including possible restrictions relating to senior water rights and Streamflow Restoration Act requirements.

    domestic groundwater use exemption: <= 5000 gallons per day (Per project, with withdrawals from multiple wells aggregated.) · industrial groundwater use exemption: <= 5000 gallons per day (Per project, with withdrawals from multiple wells aggregated.) · lawn or garden irrigation exemption: <= 0.5 acre (For lawn or garden irrigation.) · well construction notice: 72 hours before drilling (Notice of intent is not a permit, certificate, or water-right application.)

    “The groundwater permit exemption allows for four small uses of groundwater without a water right permit: Domestic uses of up to 5,000 gallons per day Industrial uses of up to 5,000 gallons per day Irrigation of a lawn or garden, a half-acre or less in size Stockwater”
  • Mandatory utility hookupConditional

    Existing OSS failures and certain new developments statewide when public sewer service and applicable local requirements exist.

    • For an existing OSS failure within a sewer utility service area, the local health officer must require public-sewer connection if the sewer utility allows connection and adequate service is available within 200 feet measured along the usual or most feasible access route.
    • For an OSS repaired under Table X, connection is required when the local health officer deems it necessary to protect public health, adequate public sewer becomes available within 200 feet under the stated measurement rule, and the sewer utility allows connection.
    • Local boards of health may require new development to connect to protect public health.
    • Local boards of health shall require connection for new development or a development with a failing OSS when required by the comprehensive land use plan or development regulations.
    • The rule was filed March 1, 2024, and became effective April 1, 2025.

    public sewer availability distance: <= 200 feet (Measured from the existing building-drain/building-sewer connection, or where no building drain exists, from where the sewer line begins, along the usual or most feasible route of access.)

    “(b) Require connection to a public sewer system if the sewer utility allows the connection and has adequate public sewer services available within 200 feet from where the existing building drain connects to the existing building sewer, or where no building drain exists, within 200 feet from where the sewer line begins, as measured along the usual or most feasible route of access.”
  • Agricultural exemptionAvailable (with conditions)

    Temporary growing structures used solely for production of horticultural plants in Washington.

    • The exemption is limited to temporary growing structures.
    • The structures must be used solely for production of horticultural plants, including ornamental plants, flowers, vegetables, and fruits.
    • The statute states that a temporary growing structure is not considered a building or structure for purposes of chapter 19.27 RCW.
    • This is not a general exemption for residences or all agricultural buildings.
    “The provisions of this chapter do not apply to temporary growing structures used solely for the production of horticultural plants including ornamental plants, flowers, vegetables, and fruits. A temporary growing structure is not considered a building or structure for purposes of this chapter.”
  • Driveway accessRequired

    Approaches or driveway connections from abutting property to Washington county roads.

    • Permission must be obtained from the county board before construction.
    • Counties may adopt reasonable approach-construction rules, including culvert, fill-depth, and drainage requirements.
    • Construction must be supervised by the county road engineer and paid for by the person benefited.
    • Violation is a misdemeanor.
    “No person shall be permitted to build or construct any approach to any county road without first obtaining permission therefor from the board.”
    One more reviewed finding on this topic
    • Required — Approach roads and driveway connections constructed on Washington state highway rights-of-way.
      “No person, firm, or corporation may be permitted to build or construct on state highway rights-of-way any approach road or any other facility, thing, or appurtenance not heretofore permitted by law, without first obtaining written permission from the department.”
  • Building in a floodplainRequired

    Development work on property located in a Washington floodplain.

    • The applicant must contact the local government to obtain the floodplain development permit.
    • Local governments manage floodplain development under the National Flood Insurance Program.
    • Some local governments impose standards higher than NFIP minimums, including regulation of areas larger than FEMA Flood Insurance Rate Maps show.
    • Washington counties and cities planning under the Growth Management Act must periodically review and update Critical Areas Ordinances addressing frequently flooded areas.
    “If you're planning to do any development work on a property located in a floodplain, contact your local government to obtain a floodplain development permit. Local governments are responsible for managing development in floodplains under the NFIP; however, some local governments have higher regulatory standards than the minimums of the NFIP, such as regulating a larger area than what is shown on Flood Insurance Rate Maps.”
  • Campground & park staysLimited

    Recreational vehicles in the context of Washington's manufactured/mobile-home community statutes

    • The rule defines an RV as temporary and transient living quarters.
    • The RV is not occupied as a primary residence.
    • The RV is not immobilized or permanently affixed to a manufactured/mobile home lot.
    • This claim does not establish general statewide siting permission on private land; local land-use and building rules may apply.
    “(12) "Recreational vehicle" means a travel trailer, motor home, truck camper, or camping trailer that is primarily designed and used as temporary living quarters, is either self-propelled or mounted on or drawn by another vehicle, is transient, is not occupied as a primary residence, and is not immobilized or permanently affixed to a manufactured/mobile home lot.”
    One more reviewed finding on this topic
    • Limited — Camping and temporary occupancy in Washington State Parks facilities
      “The maximum length of stay shall be no more than 10 nights in one park within a 30-day period. Total nights stayed by the same camping party must not exceed 90 nights per calendar year in all state parks. These limitations shall not apply to those individuals who meet the qualifications of WAC 352-32-280 and 352-32-285.”
  • county zoning authorityGeneral

    Washington counties adopting zoning and related official controls for county jurisdiction, including unincorporated areas.

    • A county must create a planning agency as authorized in RCW 36.70.030 and RCW 36.70.040 before engaging in the chapter's planning program.
    • Zoning maps may be adopted only for areas covered by a comprehensive plan containing at least a land use element and a circulation element.
    • Zoning regulations may address land uses, building location and dimensions, yards and open spaces, population density, lot coverage, parking, and minimum gross floor area requirements for single-family detached dwellings.
    • The cited enabling provisions do not state a population threshold, named-county limitation, or special geographic limitation.
    “Any board, by ordinance, may establish classifications, within each of which, specific controls are identified, and which will regulate:”
    One more reviewed finding on this topic
    • General — Washington counties may plan and adopt zoning and other official controls for county land, including unincorporated areas, through their boards and planning agencies.
      “Such official controls may include, but are not limited to, ordinances establishing zoning, subdivision control, platting, and adoption of detailed maps.”
  • county building authorityGeneral

    Washington counties requiring and enforcing building permits and adopting amendments to the state building code for residential construction within county jurisdiction, including unincorporated areas.

    • The state building code must be enforced by counties and cities within their jurisdictional boundaries.
    • A county without a building department must contract with another county, city, or approved inspection agency for enforcement.
    • County amendments may not diminish the minimum performance standards and objectives of the state building code.
    • Residential-building amendments are subject to approval by the state building code council under RCW 19.27.074(1)(b), except as provided by statute.
    • The building-permit definition incorporates exemptions in International Building Code section 105.2 and International Residential Code section R105.2.
    • Counties may adopt permit exemptions for certain specified R-3 or M-1 construction or alteration with total fair market value not exceeding $1,500, but the exemption does not remove substantive code standards.

    permit-exemption fair-market-value ceiling: <= 1500 USD (Applies only to certain construction or alteration of group R, division 3, or group M, division 1 occupancies under RCW 19.27.060(7); substantive code standards still apply.)

    “The state building code required by this chapter shall be enforced by the counties and cities. Any county or city not having a building department shall contract with another county, city, or inspection agency approved by the county or city for enforcement of the state building code within its jurisdictional boundaries.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission — ask the county directly.

  • Minimum lot size — Minimum lot size in unincorporated San Juan County.
  • Camping on your land — Temporary camping on private land in unincorporated San Juan County.
  • Off-grid sanitation — Off-grid sanitation in San Juan County.
  • Short-term rentals — Short-term or vacation-rental use in San Juan County.

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.

Living off-grid in San Juan County, Washington

Is San Juan County a good place to live off-grid or homestead?

San Juan County scores 55/100 on the Bolthole Index, a solid county profile. Watch-outs: more administrative friction around building and land use and sparse surroundings — about 3,212 people within a 30-minute drive.

Do you need a building permit in San Juan County, Washington?

San Juan County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by San Juan County Health & Community Services (Environmental Health). Owner-builders may act as their own contractor to build their home. These answers are quoted from official sources and independently re-checked. Rules change and cities within the county differ — always confirm with the county before you buy or build.

How much does land cost in San Juan County, Washington?

Land in San Juan County runs about $12,320 per acre, based on the latest county data.

What is the water situation in San Juan County?

San Juan County gets about 28.8" of rain a year, with severe drought in roughly 5.6% of years.

How remote is San Juan County?

A typical private-land location has about 13,651 people within 15 miles and 7,164,936 within 100 miles. These radius catchments are the published fallback where road routing is unavailable.

How San Juan compares in Washington

Compare side-by-side →See all 39 Washington counties ranked →