A completed single-story barndominium with a long, low roofline and no upper-level windows.

Small Barndominium Floor Plans in Kansas

A small barndominium is the easiest building on this site to frame and the easiest to underestimate. Shrinking the footprint does not shrink the things that are sized by rule rather than by square footage: the minimum room sizes in the residential code, the septic tank, the frost-depth footing under a house, and a safe place to be when a Kansas storm arrives in the late afternoon. Get those four right and a 900- to 1,400-square-foot plan lives larger than its footprint.

What actually changes with this feature

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

The code's minimum rooms

The 2018 International Residential Code sets the floor for a habitable room at 70 square feet, kitchens excepted, with no horizontal dimension under 7 feet, and asks for a 7-foot ceiling in habitable rooms and hallways (6 feet 8 inches in bathrooms and laundry rooms). Those are the numbers a compact plan runs into when it tries to squeeze a second bedroom out of a 30-foot-wide building. They are generous enough that a well-drawn small plan never feels them — but a bedroom carved from leftover space often does.

Septic is sized by bedrooms, with a floor

KDHE's Bulletin 4-2 designs the absorption field by bedrooms and soil, not by floor area: at a percolation rate of 16 to 30 minutes per inch it recommends 250 square feet of trench bottom per bedroom. A two-bedroom small house therefore needs roughly two-thirds of the field of a three-bedroom one, but the tank minimum does not fall below 1,000 gallons. If a garbage disposal is planned, the bulletin requires the tank to hold three times the daily flow. Where your county has adopted a sanitary code it governs and may be stricter, so check it before a plan is fixed.

Where you shelter without a basement

Most small barndominiums are slab-on-grade, which removes the default Kansas shelter. The National Weather Service's Kansas climatology puts about 85 percent of the state's tornadoes between 2 and 10 PM Central — when people are home. FEMA P-320 contains construction drawings for an in-residence safe room, commonly a reinforced interior closet or bath; under the 2018 IRC such a shelter follows the ICC 500 standard. Designing it in costs a few square feet of a small plan and a heavier slab under that room.

Make the shell do the work

A clear-span post-frame or steel shell has no interior bearing walls to plan around, which is the real advantage at a small size: one open room for kitchen, dining and living, with the bedrooms and bath in a single block along one end. Keep plumbing on one wet wall, put storage in a loft over the bedroom block rather than in closets, and let a covered porch take the space a mudroom would otherwise need.

A completed single-story barndominium with a long, low roofline and no upper-level windows.
What does not shrink

A smaller house still gets a full-size septic tank and a full-depth footing

KDHE's Bulletin 4-2, the state health department's minimum standards for onsite wastewater systems, sizes everything by bedrooms at 150 gallons per bedroom per day — and then sets a floor. Its tank table gives the same 1,000-gallon minimum for a one-, two- or three-bedroom home, with 1,350 gallons recommended, and says no tank is ever smaller than 1,000 gallons. So a one-bedroom cabin-style barndominium carries the same tank as a three-bedroom one. The footing works the same way: unincorporated Johnson County's foundation guideline, for example, lets only a freestanding accessory structure of 600 square feet or less, with an eave of 10 feet or less, use a shallower footing than the frost footing a house gets. A small dwelling is not a small shed, and a plan that is priced as one will be corrected at the first inspection.

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.

One-bedroom retreat

864 sq ft (24' x 36') / 1 bedroom, 1 bath, open great room

The weekend or retirement plan. A single bedroom and bath at one end, an open great room at the other, and a reinforced bath or closet doubling as the storm room. The septic tank is still the 1,000-gallon minimum, but the absorption field is sized for one bedroom, which can decide whether a small or tight parcel works at all.

Two bedrooms and a flex room

1,200 sq ft (30' x 40') / 2 bedrooms, 1.5 baths, office

The most common small program. Two bedrooms that each meet the 70-square-foot minimum with room for a bed and dresser, an office that is not called a bedroom, and a half bath off the entry. Every sleeping room needs its own code-size escape window, so the office stays an office unless the window is drawn big enough.

Small house beside a big shop

1,000 sq ft living / 1,500 sq ft shop under one roof

For owners who need equipment space more than living space. The house half is compact and complete; the shop half is a separate fire area with its own slab and doors. Where the shop is attached, expect the building official to ask for the kind of gypsum separation the code requires between a house and an attached garage — plan the shared wall with the layout, not after.

Small Barndominium: common questions

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

What is the smallest barndominium I can build in Kansas?
The building code sets minimum room sizes rather than a minimum house size: under the 2018 IRC a habitable room must be at least 70 square feet (kitchens excepted) and at least 7 feet in any horizontal dimension. Minimum dwelling sizes, where they exist, come from city and county zoning, and they vary widely — some rural counties set none. Ask the zoning office for your parcel before choosing a footprint.
Does a small house get a smaller septic system?
The field, yes; the tank, no. KDHE's Bulletin 4-2 sizes the field at 150 gallons per bedroom per day and a per-bedroom trench area that depends on how fast your soil drains, so fewer bedrooms means a shorter field. But the bulletin's minimum tank is 1,000 gallons for anything up to three bedrooms. A county sanitary code, where one has been adopted, governs, and the bulletin notes some local codes require a percolation test.
Can a small barndominium sit on shallow footings like a shed?
Not if people live in it. Unincorporated Johnson County's foundation guideline, for example, allows shallower footings only for freestanding accessory structures of 600 square feet or less with an eave of 10 feet or less; a house gets the full frost footing. Frost depths are set by the city or county whose code applies, not by the state.
Where do we shelter in a small house with no basement?
Plan an in-residence safe room. FEMA P-320 provides construction drawings for a residential safe room that can double as a closet or bathroom, and under the 2018 IRC a storm shelter built as a safe room follows ICC 500. The National Weather Service says about 74 percent of Kansas tornadoes historically fall between April and June, so this is a room you will use. Ask any prefabricated shelter maker for its ICC 500 listing.
Is a small barndominium cheaper per square foot?
Usually not. The fixed costs — septic tank, well or water connection, electrical service, kitchen, bathroom and the permit — are nearly the same for 900 square feet as for 1,800, so they are spread over fewer feet. We do not publish our own prices; ask for a line-item estimate and look at those fixed items first.
Can I add on to a small barndominium later?
Yes, if you plan it now. Leave the gable end you intend to extend free of plumbing and the electrical panel, size the septic field and reserve area for the bedroom count you expect to end with, and keep the frame's bay spacing consistent so the extension matches. KDHE's bulletin already recommends marking and fencing a reserve area equal to the field — use it.

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

Start your plans

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.