Do Barns and Farm Buildings Need a Permit in Washington? Spokane and Lincoln County Rules for Ag Buildings (2026)

In Washington, a barn or machine shed generally still needs a building permit. Unlike Idaho or Oregon, Washington has no broad statewide exemption for farm buildings. What state law does give farm buildings is a legal definition, a cap on what counties can charge to permit them, and an exemption for temporary growing structures. Here's how that plays out for hay barns, machine sheds and livestock buildings in Spokane and Lincoln counties.

What Washington counts as an "agricultural structure"

RCW 19.27.015 defines an agricultural structure as a structure designed and built to house:

• Farm implements such as tractors, combines and sprayers
• Hay and grain
• Poultry and livestock
• Other horticultural products

The same definition rules some uses out. An agricultural structure may not be:

• A place of human habitation
• A place of employment where agricultural products are processed, treated or packaged
• A place used by the public

So a hay barn or machine shed fits. A shop with an apartment, a packing shed with employees, or a barn used for public events does not.

What state law actually exempts

Washington's building code law (Chapter 19.27 RCW) has two provisions farmers tend to hear about:

• Temporary growing structures: RCW 19.27.065 says the state building code doesn't apply to temporary growing structures used solely to produce horticultural plants, such as ornamental plants, flowers, vegetables and fruits
• Permit fees for ag buildings: RCW 19.27.087 says permit and plan review fees for agricultural structures may only cover the local government's actual costs of processing, plan review, environmental review and inspections

Neither one exempts a permanent barn, pole building or steel machine shed from needing a permit.

Spokane County: barns are not on the exempt list

Spokane County's permit exemption handout (BP-25) lists common work that needs no permit from Building and Planning. The items that matter for farm and rural owners are:

• Small sheds: one-story detached accessory buildings used as tool and storage sheds, playhouses and similar uses, up to 200 sq ft
• Shade cloth structures built for nursery or agricultural purposes, not including service systems
• Retaining walls up to 4 feet from the bottom of the footing to the top of the wall, unless they support a surcharge
• Driveways, walks and platforms no more than 30 inches above grade

Barns, machine sheds and livestock buildings aren't on that list. The County also notes that exempt work still has to stay out of setbacks and easements, meet lot coverage limits, and stay off the county right-of-way without Public Works approval.

Spokane County's pole building handout

Spokane County publishes a typical cross-section for a residential or agricultural pole building (BP-32) that owners can use as part of a permit submittal. It has limits:

• Truss span: 36 feet maximum
• Building size: 3,000 sq ft maximum
• Snow load: no more than 43 psf ground snow (30 psf roof snow)
• Footing inspection: before footings are filled, to check diameter, depth and setbacks
• Framing and final inspection: after the structure is framed and the siding and roofing are on, before you use the building

A bigger machine shed, a wider clear span or a site with a higher snow load means engineered plans. Our Spokane County snow load guide explains how the load is set for your parcel.

Lincoln County: permits required, with an ag appendix

Lincoln County, which covers Reardan, Davenport and the farm ground west of Spokane County, takes a similar line:

• Permit required: the County code says a permit is needed for each building or structure except outbuildings meeting the 200 sq ft exception or work listed in IBC Section 105.2
• Ag appendix adopted: the County adopts IBC Appendix C, Group U Agricultural Buildings
• Design criteria: 50 psf ground snow, 40 psf roof minimum, 30-inch frost depth and 85 mph wind
• Pole buildings: the County's non-residential permit page says poles must be in their holes before inspection
• Road approaches: access permits are required for approaches onto every county road, and existing approaches are re-evaluated when the use changes

Our pages on pole buildings in Reardan and pole buildings in Davenport go through the Lincoln County process in more detail.

Things that turn a farm building into something else

Because the definition is about use, a building's status can change:

• Living space: an apartment or bunk room makes it a place of human habitation, which the definition excludes
• Processing with employees: packing or processing farm products with workers inside is excluded
• Public use: events, sales to the public or lessons are excluded
• Shop use: a building for a welding or repair business is a commercial building, even on farm ground

If you think you might add any of those later, tell the County and your builder up front. It's much easier to design for it now than to re-permit later.

Permits that apply either way

• Electrical: wiring is permitted and inspected separately, through Washington L&I outside cities that run their own electrical program
• Plumbing and septic: in Lincoln County, a building with plumbing needs Health Department sewer and water approval first
• Setbacks and critical areas: zoning setbacks, floodplains and wetlands still apply. See our guide to how close to the property line you can build a shop

How Raven handles farm buildings

Raven Buildings builds pole barns, machine sheds and pre-engineered steel buildings across Spokane, Lincoln, Stevens and Pend Oreille counties. We aren't tied to one steel manufacturer, so we source from whoever can deliver fastest. We draw the site plan, get engineered plans for your county's snow load, and handle the permit and inspections.

• Our installed rate: about $60 to $75 per sq ft for an installed pole building or PEMB. Electrical, plumbing and utility hookups are extra
• Read more: red iron vs. pole barn, pole barn post depth and site prep

Planning a barn or machine shed? Call 509-350-2016 or request a free quote with the size, door openings and your parcel number.

Sources

• Installed pricing: Raven Buildings' current going rate
• Chapter 19.27 RCW, State Building Code (Washington State Legislature)
• Spokane County BP-25: Permit Exemptions (PDF)
• Spokane County BP-32: Pole Buildings (PDF)
• Lincoln County Building Code, Chapter 15.03 (PDF)
• Lincoln County, WA: Design Guidelines
• Lincoln County, WA: Non-Residential Buildings