Can You Live in Your Shop in Spokane County? Barndominium, Shouse and Shop Apartment (ADU) Rules (2026)

A lot of shop owners in Spokane County picture the same thing: a big metal shop with a finished apartment on one end, or a full barndominium where the house and the shop share one roof. You can build either one legally. The catch is that a shop permitted as a garage or storage building isn't a dwelling, and the rules change the moment someone sleeps there. Here's how Spokane County treats a "shouse," a shop apartment and a barndominium, and what the building code asks for.

Three ways to live in a shop

• A barndominium or shop-house as your only home: the living area is the house. It's permitted as a single-family dwelling under the residential code, and the shop part is an attached garage
• An apartment in a shop next to your existing house: that's a detached accessory dwelling unit (ADU), and Spokane County's zoning limits apply
• Sleeping in a shop permitted as a garage or storage building: that isn't an approved dwelling. A shop permit covers an accessory building, not living space

Option 1: the barndominium or shouse as the main house

When the living space is your primary residence, Spokane County reviews it like any other house. That means the International Residential Code (IRC), which Washington adopts statewide, plus the Washington State Energy Code for the living area. The shop half is treated as a garage attached to the house, so the code's garage separation rules apply:

• Wall between the shop and the house: at least 1/2-inch gypsum board on the garage side (IRC R302.6)
• Living space above the shop: at least 5/8-inch Type X gypsum board on the ceiling below it
• Door between them: solid wood or solid or honeycomb-core steel at least 1-3/8 inches thick, or a 20-minute fire-rated door (IRC R302.5.1)
• No door straight from the shop into a bedroom: the code doesn't allow openings from a garage directly into a sleeping room

Our PEMB barndominium checklist walks through the pre-build steps, and our barndominium vs. stick-built comparison covers the tradeoffs.

Option 2: an apartment in a shop next to your house

If you already have a house and want living quarters in the shop, Spokane County treats that as a detached accessory dwelling unit: a second dwelling with its own kitchen, sleeping and bathroom on a lot that already has a main house. The County's detached ADU handout (BP-75) lists the rules for the rural zones where detached ADUs are allowed outright (Rural-5, Rural Traditional, Rural Activity Center and Urban Reserve):

• One ADU per lot with an existing single-family house, and not on a lot with a duplex or an attached ADU
• Within 150 feet of the main house
• No more than two bedrooms and no more than 800 square feet on the main (ground) floor
• A pitched roof of at least 4:12, with the ridge no higher than 24 feet
• A title notice saying the ADU can't be sold separately unless it ends up as the only home on a legally divided parcel
• Built to the IRC as a single-family dwelling and to the Washington State Energy Code, and inspected before anyone moves in
• Adequate water and septic or sewer, with a separate shut-off valve for the ADU's water service. The Spokane Regional Health District handles the well and septic side

In the County's urban residential zones (Low, Low Plus, Medium and High Density Residential), BP-75 says a detached ADU needs a conditional use permit with a public hearing, which the County says takes about 60 to 90 days, plus a minimum lot of 10,000 square feet and an extra off-street parking space.

State law has changed the urban rules

BP-75 dates to 2012. Since then, Washington passed a 2023 law (RCW 36.70A.681) that sets minimum ADU rules for cities and counties planning under the Growth Management Act, inside urban growth areas. It says they must allow at least two ADUs on lots in zones that allow single-family homes, can't cap ADU size below 1,000 square feet, can't set a roof height limit under 24 feet (unless the main house's limit is lower), can't require the owner to live on the lot, and must allow ADUs converted from existing structures such as detached garages. These limits don't apply to lots with critical areas or their buffers.

So the answer depends on whether your parcel is rural or inside the urban growth area, and what the County's current code says. Ask a County planner before you design the apartment end of a shop.

Code basics for any shop living space

Whether it's a barndominium or an ADU, the living area has to meet the same residential code items as a house. A few that change a shop's layout:

• Egress from every bedroom: each sleeping room needs an emergency escape opening, either a door or a window (IRC R310)
• Smoke and carbon monoxide alarms: required in dwellings under the IRC (R314 and R315), and the CO alarm rule applies to homes with an attached garage
• Energy code: the living space has to meet the Washington State Energy Code for insulation, windows and air sealing. A metal building's walls and roof need an insulation assembly that meets the residential energy code. See our guides to insulating a metal building and windows in a metal building
• Plumbing and electrical permits: a bathroom or kitchen in a shop means plumbing, mechanical and electrical permits on top of the building permit

What about the steel building itself?

The structure is the easy part. A pre-engineered metal building is designed for the site's snow and wind loads either way, and the living space is framed inside it. What changes is the paperwork and the interior. Plan the apartment or living area before the building is ordered, so door and window openings, the roof pitch (a 4:12 roof if it's going to be a rural ADU) and the slab plumbing are in the right places.

For the shell, Raven's current going rate for an installed PEMB or pole building in the Spokane area is about $60 to $75 per square foot. Electrical, plumbing and utility hookups are extra, and the finished living space (walls, insulation package, kitchen and bath) is quoted separately for each project. Raven isn't tied to one steel manufacturer, so we source from whichever one can deliver fastest.

Before you build, check these

• Who issues your permit: unincorporated Spokane County, the City of Spokane or another city. Our shop permit plans guide covers the site plan and review times
• Your zone: rural or urban, and whether a detached ADU is allowed outright or needs a hearing
• Setbacks: see our rural setback guide
• Water and septic: whether your well and septic system can serve another dwelling, through the Spokane Regional Health District

Get a quote for a shop with living quarters

Raven Buildings builds PEMB and pole buildings with the slab and footings poured by our own concrete crew. Call 509-350-2016 or request a free quote with your address, the building size you have in mind, and whether the living space is your main house or an ADU. See our steel building services.

Sources

• Shell pricing: Raven Buildings' current going rate for the Spokane area
• Spokane County BP-75, Accessory Dwelling Units - Detached
• Spokane County BP-76, Accessory Dwelling Units - Attached
• Spokane County Zoning Code
• RCW 36.70A.681, Accessory dwelling units, limitations on local regulation
• WAC 51-51-003, Washington's adoption of the International Residential Code
• 2021 International Residential Code, Chapter 3 (R302 fire separation, R310 egress, R314-R315 alarms)
• Spokane Regional Health District