40' x 60' · 2,400 sq ft footprint

40x60 Barndominium Floor Plans in California

The 40 by 60 foot barndominium is the most common size in the building type, and for good reason. Its 2,400 square feet fit a three- or four-bedroom home on one level, or a two-bedroom home with a large shop under the same roof. A 40-foot width is a comfortable clear span for a steel rigid frame and a standard truss length for a pole barn building, so the structure stays simple. In California the 40x60 also carries a large, unbroken roof, roughly 2,400 square feet in plan before the overhangs, which gives the solar array plenty of room on its sunny slope.

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What actually changes at this size

The dimensions are the easy part. These are the decisions that follow from them.

Frame bays set the window rhythm

A steel 40x60 usually has main frames every 20 to 25 feet; a pole barn has posts every 8 to 12 feet. Doors and windows fit most easily between frames or posts, not through them. Laying the rooms out on that rhythm keeps big openings where the structure wants them and avoids costly extra framing.

A roof big enough for the whole solar array

One slope of a 40x60 gable roof is about 60 feet long and over 20 feet deep, a large, simple area for panels. Face a long side south or west where the site allows, keep the vents and the range hood on the other slope, and the array fits in one block with room to grow. Under the 2025 Energy Code, a new single-family home generally needs a solar PV system sized by a state formula; small or shaded roofs can be exempt, and a qualifying battery can cut the required size by 25 percent.

Heat in a 2,400 square foot box

A 40-foot-deep plan puts the middle rooms far from the outside walls, so daylight and air need planning. A vaulted great room in the centre, clerestory windows, and ducts kept inside the insulated space make a deep plan comfortable. On an inland site, a porch on the south and west sides takes the worst of the afternoon sun off the long wall.

Sprinkler and water supply for a full-size house

New one- and two-family homes in California need an automatic fire sprinkler system under California Residential Code R309, installed by a licensed fire-protection contractor. On a well, a 2,400 square foot house with three bathrooms and a fire sprinkler system needs a water supply planned for both. Storage tanks and a pump sized for the sprinkler demand are common on rural parcels, and they go on the site plan with the septic system.

The span and the bracing

A 40-foot clear span leaves the inside open, so the outside walls do the bracing

With no interior columns, a 40x60 steel frame puts all of its resistance to earthquake and wind forces in the main frames and the end and side walls. That is what lets the floor plan put walls anywhere inside. It also means the large openings, such as shop doors, a wall of glass on the gable end or a row of sliding doors onto a porch, have to be placed with the bracing in mind. On a pole barn frame, the posts, the sheathed walls and the roof diaphragm do the same job. The seismic, wind and snow design values are set for your site, and the structural drawings are prepared for them.

How people actually split 2,400 sq ft

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

Full home, three or four bedrooms

2,400 sq ft living / 3-4 bed, 2-3 bath

The whole building as a house: a split-bedroom plan with the primary suite at one end, two or three bedrooms at the other, and a vaulted great room, kitchen and dining in the middle. A 10-foot porch on the south or west side adds shade and outdoor space outside the 40x60 footprint.

Half home, half shop

1,200 sq ft living / 1,200 sq ft shop

A two-bedroom home at one end and a 30 by 40 foot shop with two overhead doors at the other. A mudroom, laundry and half bath between them act as a buffer, and a fire-rated wall separates the shop from the living space. The shop roof carries the solar array and the shop wall holds the equipment.

Home with a two-car garage

1,800 sq ft living / 600 sq ft garage

A three-bedroom home with a 24 by 25 foot garage at one end, entered through a mudroom and laundry. The garage wall takes the electrical panel, the vehicle charger and the solar equipment, which keeps them out of the living space.

Ways to build this size

A 40' x 60' footprint can go together several ways. These are the service lines most relevant to it.

Barndominium Kits

Barndominium kits for sale in California: steel and pole barn shell packages, kit vs modular vs manufactured explained, and what California adds.

Steel Frame Homes

Steel barndominiums and metal buildings in California: red-iron frames sized for your site's loads, erected on your land, shell to finished home.

Pole Barn Homes

Pole barn homes in California: wood-framed barndominiums and pole barn home kits, drawn for your county's plan check and built on your land.

40x60 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 many square feet is a 40x60 barndominium?

2,400 square feet on the ground floor, measured to the outside of the frame. Porches and overhangs are extra. A loft over part of it adds more.

How many bedrooms fit in a 40x60 barndominium?

Three or four bedrooms and two or three bathrooms as a full home, or two bedrooms if half the building is a shop or garage. The clear span lets the interior walls go anywhere, so the split between living, garage and shop is your choice.

Is a 40x60 barndominium available as a kit?

Yes, 40x60 is one of the most common kit sizes. A kit supplies the frame, roof and wall panels and fasteners; the foundation, interior framing, insulation, utilities, finishes and the site-specific structural drawings are separate. In California the kit's frame is checked against the seismic, wind and snow values for your site before it is permitted. Plans for a wood-frame house of up to two stories can be drawn by anyone, but a steel-frame home needs structural plans stamped by a licensed engineer or architect.

Steel frame or pole barn frame for a 40x60?

Both are common at this size. A steel rigid frame gives a completely open interior and suits tall doors. A pole barn frame uses wood posts and trusses, is easy to insulate and finish, and is often lower in cost. Wildfire zone, site access and the size of the doors often decide it.

How do I keep a 40x60 cool in an inland summer?

Orient the long walls north and south, add a porch on the west and south sides, choose a light-coloured roof, insulate the roof well, and keep the ducts inside the insulated space. The Title 24 energy code sets the insulation and window values for your climate zone, and the plan is drawn to meet them.

Can a 40x60 barndominium be built in a wildfire zone?

Yes. In a Fire Hazard Severity Zone, homes are built to the California Wildland-Urban Interface Code (Part 7 of Title 24), which covers Class A roofs, eaves, vents, exterior walls, windows, doors and decks; your building department confirms the specific assemblies. Enclosed eaves, ember-resistant vents, noncombustible gutter guards and a clear zone right around the building are the usual details, and they are drawn in from the start.

Keep reading

The pages that answer the next question this one raises.

30x40 barndominium floor plans

Half the size: 1,200 square feet for a smaller house or a second home.

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Barndominium with shop floor plans

Shop doors, separation and ventilation in a house-and-shop building.

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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 2025 California Building Standards Code (Title 24 of the California Code of Regulations), in effect since January 1, 2026. Cities and counties can keep local amendments adopted before October 2025 and can add wildfire home-hardening rules, but a state moratorium blocks most new local code changes for homes until June 2031. Snow load, wind speed, frost depth and seismic design category are set for your site by the local building department.

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Tell us what you want to build and we will draw a 40' x 60' building 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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