Barndominium Permits & Zoning in Washington State
A barndominium in Washington State is a house, and it goes through the same permits as any other house. Cities and counties enforce the state building code and issue residential building permits, usually the city building department inside city limits and the county in unincorporated areas. Around that permit sit the approvals that decide rural builds: evidence of an adequate water supply, a septic permit from the local health jurisdiction, the energy code credits on the drawings, and the county's rural zoning. We handle the permit application and set out the order the rest has to happen in.
City or County: Who Issues Your Building Permit
Washington has one state building code, which adopts the International Residential Code and is in effect in all counties and cities. The state does not issue house permits itself: the code is enforced by the counties and cities, and a county or city without its own building department has to contract with another county, city or an approved inspection agency for enforcement. In practice the city building department usually issues the permit inside city limits and the county in unincorporated land, but a small town may contract its permits out, so the service area pages name the office for each city and county we cover. Local amendments to the residential code also need the State Building Code Council's approval.
The code is the same everywhere, but the numbers are not. Each local jurisdiction sets the climatic and geographic design criteria for its area in its design table, so the snow load, wind, frost depth and seismic values on your drawings come from the office that issues your permit.
Water, Septic, Energy Code and Zoning
Water is the Washington gate. State law requires anyone applying for a building permit for a building that needs potable water to provide evidence of an adequate water supply: a water right permit from Ecology, a letter from an approved water purveyor, or another form sufficient to show the supply, which in most areas can be a water well report. An application for a water right is not enough. The Department of Ecology describes the 2016 Hirst decision as a Washington State Supreme Court decision that limited a landowner's ability to get a building permit for a new home when the proposed water source was a permit-exempt well; the Legislature followed it with the Streamflow Restoration Act in 2018. In the watersheds that Act covers, a new home on a new permit-exempt well pays a fee, has a lower annual-average withdrawal cap, and the limit is recorded on the property title.
Septic is permitted separately. Off sewer, the on-site sewage system needs a permit from the local health officer before construction, based on a soil and site evaluation and a design that reserves space for a replacement drainfield. The septic application names the drinking water source, so water and septic are usually worked out together.
The energy code shapes the drawings. The Washington State Energy Code requires each new house to earn additional energy efficiency credits by size, and the drawings submitted with the building permit have to identify the options chosen and their credit values.
Zoning decides whether the house can go there at all. Under the Growth Management Act, each county's comprehensive plan sets rural densities, and the county zoning code sets the actual minimum lot size. Land within 200 feet of the ordinary high water mark of a regulated shoreline falls under the county or city shoreline master program: an owner's own single-family home under 35 feet tall is generally exempt from a shoreline substantial development permit, but it still has to meet the program's rules. We check zoning and shoreline before anything is drawn.
Permitting: how the work runs
Four stages, in this order. The sequence matters more than it looks: on rural Washington land, settling the water supply, the septic permit and the building permit before anything is fabricated is what keeps a build from stalling.
Jurisdiction and zoning check
We confirm whether the parcel is in a city or unincorporated county land, what the zoning allows, and whether shoreline rules, wetlands or steep slopes affect it. That tells us who issues each permit and what the house has to fit around.
Water and septic
The water evidence and the septic permit come first on rural land. You hire the well driller or arrange the water system letter, and a septic designer works with the local health jurisdiction on the soil evaluation and design; we plan the house around both.
Permit set and application
We prepare the drawings with the energy code credits and your jurisdiction's design values, and handle the building permit application to your city or county building department.
Review, revisions and inspections
We answer plan review comments and revise the drawings, then the building department inspects the work at the stages it calls for through to the final inspection.
No water evidence, no building permit
Washington law requires evidence of an adequate water supply for a building permit on any building that needs potable water, and a water right application alone does not count. In Streamflow Restoration watersheds, a new home on a new permit-exempt well pays a fee and has a lower withdrawal cap recorded on the title. On rural land, the water question is the first one we answer.
Where we deliver permitting
In Washington the first line that matters is usually a city limit. Cities and counties enforce the state building code and issue residential building permits: usually the city building department inside city limits and the county in unincorporated land, where most barndominiums are built and where the county's comprehensive plan sets rural densities. The state building code is the same on both sides of every line. What changes is the zoning, the snow, wind, frost and seismic values the jurisdiction sets, the local health jurisdiction that permits the septic system, and how the house shows an adequate water supply.
Barndominium builders across Washington State.
Every city and county has its own answer on permits, septic and water. The service area pages set out what each one publishes.
What actually decides the price
Square footage is the number everyone leads with, and it is rarely the one that moves a barndominium budget. These four do.
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Permit and plan review fees
Building permit and plan review fees are set by each city and county, and septic permit fees by each local health jurisdiction. They vary, so they are taken from your jurisdiction's own fee schedule.
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Water evidence
A letter from a water system is usually quick. A new well, a water right or a basin with Streamflow Restoration Act requirements takes longer and can add fees.
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Reports and studies
A wetland, stream, steep slope or floodplain on or near the parcel can mean extra studies before the permit is issued, and the county tells you which. That adds cost and time.
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Plan review rounds
A complete first submittal with the energy credits, site plan and frame drawings in it saves review rounds. Each round adds weeks.
Permitting in Washington: common questions
8 questions we get asked most often about building in Washington. If yours is not on the list, ask it directly.
Who issues a building permit for a barndominium in Washington?
Is there a statewide building code in Washington?
What is the Hirst decision and does it affect my build?
What if my acreage is in a current-use tax program?
What does the energy code require for a new barndominium?
Can I build a barndominium on rural or farm land in Washington?
Is a barndominium treated differently from a normal house?
Do I need an architect or engineer for the permit?
Sources
- RCW 19.27.031, State building code adoption — Washington State Legislature
- RCW 19.27.050, Enforcement by counties and cities — Washington State Legislature
- RCW 19.27.074, State Building Code Council duties (approval of local residential amendments) — Washington State Legislature
- WAC 51-51-0301, Residential code design criteria (Table R301.2) — Washington State Legislature
- RCW 19.27.097, Building permit application: evidence of adequate water supply — Washington State Legislature
- RCW 90.94.020, Streamflow restoration: permit-exempt domestic withdrawals (WRIAs 1, 11, 22, 23, 49, 55, 59) — Washington State Legislature
- RCW 90.94.030, Streamflow restoration: permit-exempt domestic withdrawals (WRIAs 7 to 10 and 12 to 15) — Washington State Legislature
- Streamflow restoration — Washington State Department of Ecology
- WAC 246-272A-0200, On-site sewage system permits — Washington State Legislature
- Regulatory Jurisdiction for On-site Wastewater (Sewage) Systems — Washington State Department of Health
- WAC 51-11R-40620, Energy code additional energy efficiency requirements (R406.3) — Washington State Legislature
- RCW 36.70A.070, Comprehensive plans: rural element — Washington State Legislature
- RCW 84.34.080, Current use classification: change of use, additional tax and penalty — Washington State Legislature
- RCW 90.58.030, Shoreline Management Act definitions — Washington State Legislature
- RCW 18.08.410, Architects: exemptions — Washington State Legislature
Keep reading
The pages that answer the next question this one raises.
Are Barndominiums Legal in Washington State?
The state building code, water supply evidence, septic and rural zoning explained.
Read itHow Long Does It Take?
How the approvals fit into the whole build schedule.
Read itWhere We Build
Who issues the building and septic permits, city by city and county by county.
Read itReady to put permitting against a real plan? Start there and the rest follows.
Tell us about the land
Tell us where the parcel is and what you want on it, and we will come back with who has jurisdiction, what the land needs before it can be built on, and a realistic budget range. Starting the survey costs nothing.