Small Barndominium in Indiana

Small barndominium floor plans are the ones we are asked about most: a one- or two-bedroom home in a simple steel or post-frame shell, often with a garage or shop bay attached. In Indiana, the smallest house you can build on a given parcel is not set by the building code. The 2020 Indiana Residential Code will accept a very small dwelling, and it made the model code's tiny-house appendix mandatory. The floor is set by county and town zoning, which often requires a minimum ground floor area for a dwelling — and those minimums vary several-fold between counties. So a small barndominium starts with the zoning district of the land, then fits the plan to it. A garage, shop bay or open porch attached to the house usually does not count toward the minimum.

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What actually changes with this feature

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

Under 400 square feet, Indiana's tiny-house rules apply

675 IAC 14-4.4-242 adopts Appendix Q of the International Residential Code and deletes the sentence that made it optional. Appendix Q defines a tiny house as "a dwelling that is 400 square feet (37 m2) or less in floor area excluding lofts," and adjusts a few rules for it: a minimum ceiling height of 6 feet 8 inches for habitable space and hallways and 6 feet 4 inches for bathrooms, toilet rooms and kitchens (AQ103.1), and loft access by stairs, ladders, alternating-tread devices or ship's ladders (AQ104.2). Everything else in the residential code still applies. Zoning is a separate gate: a 400-square-foot house meets the building code and still has to meet the district's minimum floor area.

Rooms still have minimum sizes

A small plan is still held to the residential code's room rules. IRC R304.1 requires every habitable room to have at least 70 square feet of floor area (kitchens excepted), R304.2 requires every habitable room to be at least 7 feet in any horizontal dimension, and R305.1 sets a 7-foot minimum ceiling height for habitable space outside the tiny-house appendix. Every sleeping room needs an emergency escape and rescue opening under R310.1. Those rules decide how many bedrooms fit in a given footprint before the zoning minimum does.

Small house, smallest septic tank

If the land is on septic, the system is sized by bedrooms, not square feet. Indiana's residential on-site sewage rule sets design daily flow at 150 gallons per day per bedroom (410 IAC 6-8.3-12), and Table III of 410 IAC 6-8.3-60 sets the minimum septic tank at 750 gallons for two or fewer bedrooms, against 1,000 for three. A one- or two-bedroom small barndominium is at the bottom of that table. The septic construction permit comes from the local health department before construction of the residence starts (410 IAC 6-8.3-53).

Minimum house sizes are up for review

IC 36-7-4.3-3, added in 2026, requires each county, city and town to hold a public hearing by 1 January 2027 reviewing its development ordinance "with the goal of increasing housing development," and lists "minimum lot size and square footage" among the requirements to consider waiving or eliminating, along with provision for accessory dwelling units. A hearing does not change an ordinance by itself; until a unit amends its table, the published minimum applies. If your parcel is in a county with a high minimum, it is worth asking the planning office whether the table is being revisited.

The minimum is local

How small can a house be? In Indiana, the county's zoning table answers first

Brown County's zoning ordinance sets its minimum ground floor size for a one-story single-family dwelling at 240 square feet in its Forest Reserve (FR) district — land the ordinance describes as "for the most part rough terrain and where there is extensive public ownership of forest lands" — against 900 square feet in its R1 district and 500 in R2 and LR. Randolph County's unified zoning ordinance, Table 4.06.1, requires a minimum ground floor living area of 950 square feet for a one-story residence in its A-R district, or 720 square feet of ground floor for two or more stories with total living area of at least 950; its Agricultural Limited District sets 950 square feet for one story and 600 for two. Both ordinances measure ground floor area exclusive of open porches and garages. The same small barndominium can be permitted on one parcel and too small on another, a county line apart.

Common ways to build this

Common configurations we see. Yours does not have to match one exactly — this is a starting point for the conversation, not a catalog.

One-bedroom cabin barndominium

600 sq ft living / single level

One bedroom, one bath, a kitchen and living room under one gable, with a covered porch. At 600 square feet it clears Brown County's 500-square-foot minimum in its R2 and LR districts and its 240 in FR, but not Randolph County's 950 in A-R. It sits in the smallest septic tank size under 410 IAC 6-8.3, Table III.

Two-bedroom barndominium with a garage bay

950 sq ft living / 400 sq ft garage

Two bedrooms and one and a half baths sized to meet a 950-square-foot ground floor minimum such as Randolph County's A-R district, with a garage bay attached under the same roof. Both Randolph County and Brown County measure ground floor area exclusive of garages, so the garage does not help meet the minimum — the living area has to meet it by itself.

Tiny barndominium with a sleeping loft

380 sq ft main floor / 120 sq ft loft

Under 400 square feet excluding the loft, so Indiana's adopted Appendix Q applies: 6 feet 8 inches of ceiling in habitable space, a loft of at least 35 square feet and 5 feet in each direction (AQ104.1), and loft access by stairs or a ladder with rungs at least 12 inches wide (675 IAC 14-4.4-242). Zoning is the limit — a district with a 240-square-foot minimum, such as Brown County's FR, will accept it; a 950-square-foot district will not.

Ways to build this size

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

Custom Plans

Custom barndominium floor plans drawn for your Indiana lot, county and budget — shop bays, lofts and porches included. Start with a free plan survey.

Post-Frame Homes

Post-frame and pole barn homes for Indiana land — posts, trusses and girts designed to your county's frost and snow row. Start with a free project survey.

Barndominium Kits

Barndominium kits and shell packages for Indiana land, drawn to your county's row of the state residential code table. Start with a free project survey.

Small Barndominium: common questions

7 questions we get asked most often about this footprint. If yours is not on the list, ask it directly.

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What is the smallest barndominium I can build in Indiana?

The building code allows very small dwellings — Indiana adopted the International Residential Code's tiny-house appendix, which covers dwellings of 400 square feet or less excluding lofts. The practical limit is your county or town's zoning ordinance. Brown County sets 240 square feet for a one-story single-family dwelling in its FR district and 900 in R1. Randolph County sets 950 square feet for a one-story residence in its A-R district. Look up the minimum floor area table for the zoning district your parcel is in.

Does a garage or shop bay count toward the minimum floor area?

Usually not. Randolph County defines ground floor area as the area "exclusive of open porches, breezeways, terraces, garages, and exterior stairways," and Brown County's definition excludes open porches, breezeways, terraces, garages and stairways. So a small barndominium with a big shop bay meets the minimum only through its living area. If you are close to the line, it is cheaper to add living space than to argue about how the shop is counted.

Can a small barndominium be a tiny house?

Yes, if it is 400 square feet or less excluding lofts. 675 IAC 14-4.4-242 adopts Appendix Q and deletes the sentence that made it optional, so its rules apply wherever the Indiana code applies: 6-foot-8-inch minimum ceilings in habitable space, 6 feet 4 inches in bathrooms and kitchens, lofts of at least 35 square feet, and loft access by stairs, ladders or ship's ladders. The zoning minimum is the question that decides whether you can put it on your land.

Can I build a small barndominium as a guest house or ADU?

That depends on whether your county or town allows accessory dwelling units, and on what terms. Some Indiana ordinances allow them with their own size range. Brown County's zoning ordinance, for example, allows one accessory dwelling unit on a lot in all zoning districts, with a minimum total floor area of 400 square feet and a maximum of the lesser of 1,300 square feet or 75 percent of the primary building's total floor area; it may not be sold separately or used as a tourist home or short-term rental. IC 36-7-4.3-3 also asks every unit to consider accessory dwelling units in the housing review hearing it must hold by 1 January 2027. Read the accessory-dwelling section of your ordinance before planning a second small house on the lot.

How small a septic system does a small barndominium need?

Under 410 IAC 6-8.3, sizing is by bedroom: 150 gallons per day per bedroom of design daily flow, and a minimum septic tank of 750 gallons for two or fewer bedrooms. A room counts as a bedroom if the health department and the owner agree it could be slept in and it has at least 70 square feet, an operable window or exterior door for emergency escape, and, for new construction, a closet (410 IAC 6-8.3-6). The permit comes from the local health department.

Are small barndominium kits a good fit?

Often, because a small plan is mostly the shell. A kit still has to be designed to your county's row in the state code table — the footing depth and ground snow load differ across Indiana (675 IAC 14-4.4, Table R301.2(1)), for example 24 inches and 20 psf in Brown County, 30 inches and 20 psf in Randolph County, and 36 inches and 30 psf in Elkhart County. We can supply the shell as a kit or build it turnkey.

How do we start a small barndominium?

Tell us the parcel and how many bedrooms you need through the project survey on this site. The zoning district sets the minimum living area; the septic permit sets the bedroom count the system is sized for; the county's row in the state code table sets the footings and roof loads. We draw the smallest plan that meets all three, and add a garage or shop bay if you want one.

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

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Sources

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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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