2 Story Barndominium Floor Plans in Washington State

A two-story barndominium puts more house on a smaller footprint, which matters in western Washington, where parcels near the cities are small and every square foot of foundation, clearing and impervious surface counts. It also changes the plan more than any other choice: a stair takes a real slice of both floors, every upstairs bedroom needs an escape window that a firefighter can reach, and a tall steel or pole barn frame carries more of its load through bracing and connections. Settle the stair, the bedrooms and the bracing before the elevations.

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What actually changes with this feature

The look is the easy part. These are the decisions that follow from it.

The stair takes space on both floors

Under the 2021 International Residential Code as Washington adopts it, a stair needs at least 36 inches of clear width above the handrail, risers of no more than 7 3/4 inches and treads of at least 10 inches. A 9-foot floor-to-floor height needs about 14 risers and a run of nearly 11 feet, plus a landing at the top. Drawn early, the stair becomes the spine of the plan; drawn late, it eats a bedroom.

Upstairs bedrooms need reachable escape windows

Every sleeping room needs an emergency escape and rescue opening with at least 5.7 square feet of clear opening, a clear height of at least 24 inches, a clear width of at least 20 inches, and a sill no higher than 44 inches above the floor. On a steel or pole barn frame the girts and columns decide where a window of that size can go, so place the upstairs bedrooms against the framing layout, not the other way round.

West of the Cascades, bracing does the work

Height and weight raise the lateral loads a building has to resist. The seismic design category in the local Table R301.2 decides how much bracing, how many hold-downs and what connections the second floor needs, and in the higher categories the residential code's prescriptive limits tighten. A two-story plan with long open walls and big windows on both floors is the hardest to brace, so leave solid wall where it is needed.

East of the Cascades, roof and wall together

On the dry side, the roof over a two-story plan is still drawn to the ground snow load the county sets, and a steep simple roof keeps drifts off upper-floor windows and the entry. A second floor also puts more wall area into the energy calculation. Washington's energy code sets prescriptive minimums such as R-20+5 or R-13+10 for wood-frame walls and R-60 for ceilings, and a steel or pole barn wall has to reach the same performance through the code's envelope path.

What the building department reads first

The site's design criteria come from the local table, not the plan book

Washington's residential code, WAC 51-51-0301, says additional design criteria are established by the local jurisdiction and set out in its Table R301.2. That is where the city or county records the ground snow load, wind, seismic design category, frost line depth and flood hazard it applies. A two-story plan is the most sensitive to those numbers, because height adds to the loads its walls and bracing carry. In Seismic Design Categories D0, D1 and D2, the same WAC section adds a Washington rule: water heaters must be anchored against movement and overturning. Ask for the table before the frame is priced.

Common ways to build this

Three common ways to lay this out. Yours does not have to match one exactly — this is a starting point for the conversation, not a catalog.

Great room below, bedrooms above

30' x 40' footprint / 2,400 sq ft on two floors / 3 bed, 2.5 bath

Kitchen, dining and a vaulted great room on the ground floor with a powder room and mudroom, and three bedrooms and two baths upstairs along the long wall where the framing allows full-size escape windows.

Shop below, living above

40' x 50' shop on the ground floor / 1,400 sq ft living above

A full-footprint shop or garage with the house on the second floor. The floor between them is a dwelling-garage separation under Table R302.6, needing at least 5/8-inch Type X gypsum board or equivalent under the habitable rooms, and any door between the shop and the house needs to be a solid wood or steel door at least 1 3/8 inches thick, or a 20-minute fire-rated door, self-closing and self-latching.

Main-floor primary suite

1,500 sq ft ground floor / 900 sq ft upper floor

The primary bedroom and a full bath on the ground floor for living on one level later, with guest rooms and a bonus room upstairs under a steeper roof. Upstairs sloped ceilings must keep at least half the required floor area at 7 feet.

Ways to build this

This layout can go together several ways. These are the service lines most relevant to it.

Custom Plans

Custom barndominium plans for Washington State: floor plans and permit drawings with the energy code credits and your site's design values built in.

Steel Construction

Steel and metal building construction in Washington State: red-iron frames for barndominiums and shops, designed to your county's snow and seismic values.

Turnkey Builds

Turnkey barndominiums in Washington State: one team from land and permits to the finished, inspected house, with water, septic and energy code planned in.

2-Story Barndominium: common questions

6 questions worth settling before this plan is drawn. If yours is not on the list, put it in the survey.

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How much room does the stair take in a two-story barndominium?

More than most first sketches allow. With risers of no more than 7 3/4 inches and treads of at least 10 inches under the 2021 International Residential Code as Washington adopts it, a typical 9-foot floor-to-floor stair needs about 14 risers and a run of nearly 11 feet, at least 36 inches wide, plus landings.

Do upstairs bedrooms need escape windows?

Yes. Every sleeping room needs an emergency escape and rescue opening: at least 5.7 square feet of net clear opening, 24 inches clear height, 20 inches clear width, and a sill no more than 44 inches above the floor.

Is a two-story barndominium harder to permit in western Washington?

It is more work to brace. The seismic design category comes from the jurisdiction's Table R301.2, and in the higher categories the residential code limits prescriptive bracing and adds requirements such as anchoring water heaters. Expect the building department to look closely at wall bracing, hold-downs and the connections between floors.

Does Washington require fire sprinklers in a two-story house?

Not statewide. Washington's adoption of the residential code, WAC 51-51-0313, states that the model code's sprinkler section for one- and two-family dwellings is not adopted. A local government can adopt a sprinkler ordinance on notice to the State Building Code Council, so ask your city or county.

Can the house sit over a shop on the ground floor?

Yes, if the floor between them is built as a dwelling-garage separation. Table R302.6 calls for at least 5/8-inch Type X gypsum board or equivalent under habitable rooms above a garage, and no door may open from the garage directly into a sleeping room.

Where do the snow and wind numbers for my site come from?

From the city or county. WAC 51-51-0301 leaves those criteria to the local jurisdiction's Table R301.2, so the same two-story plan can need a different roof and bracing in two counties. Ask the building department for its table before the plan is priced.

Where this plan fits in Washington

West of the Cascades a plan answers to rain and seismic design; east of them, to snow, sun, dry acreage and wildfire. These are the areas this layout suits best.

King County

Smaller rural and suburban lots where building up keeps the footprint, clearing and drainage small.

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Snohomish County

West-side parcels where a two-story plan has to answer to rain, drainage and seismic bracing together.

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Clark County

Fast-growing southwest Washington, where lot size often sets the case for a second floor.

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Spokane County

East-side acreage where a two-story house often sits beside a separate shop, with the roof drawn for snow.

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Want this drawn for your program and your parcel? That is where a build actually starts.

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Sources

Code references on this page are to the 2021 International Residential Code as amended by Washington (chapter 51-51 WAC) and the 2021 Washington State Energy Code, Residential (chapter 51-11R WAC), in force since March 15, 2024. The State Building Code Council has scheduled the 2024 editions to take effect May 3, 2027; the edition your permit is reviewed under governs.

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Tell us what you want to build and we will draw this for your program, then confirm what it looks like on your parcel, which office permits it, and a realistic budget range. That conversation costs nothing.

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