Small Barndominium Floor Plans in Minnesota

A small barndominium, roughly 400 to 1,200 square feet of living space, is how a lot of Minnesota acreage gets its first house: a retirement place up north, a cabin replacement on a lake lot, or a compact home beside a heated shop. Small plans frame quickly, but a Minnesota winter still asks the same questions of a small house as a big one. There has to be somewhere to shed boots and snow before the living room, a septic tank sized for the bedrooms rather than the square footage, a footing below the frost line for your county, and, on a lake, a building site the shoreland rules allow.

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Small Barndominium Homes in Minnesota

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

An entry vestibule is not optional here

In a small open plan, the front door often opens straight into the kitchen. In a Minnesota January that means cold air and meltwater in the living space every time someone comes in. The small plans we draw put a closed vestibule or mudroom at the main entry, with a bench, boot tray and hooks, and a second door into the house. It costs perhaps 40 to 60 square feet and it is the room owners of small houses are most glad they kept.

The septic tank does not shrink with the house

Minnesota Rules part 7080.1930 sizes a dwelling's septic tank by bedrooms, not floor area: 1,000 gallons is the minimum for three bedrooms or fewer. A one-bedroom cabin needs that same tank, and 50 percent more capacity if the plan includes a garbage disposal or a pump that lifts sewage up to the tank. The drainfield is sized separately from the soils on your lot.

Footings go to your county's frost depth

Minnesota Rules part 1303.1600 sets the minimum footing depth for frost by county: five feet in the Zone I counties, which take in most of the northern half of the state, and 3-1/2 feet in the Zone II counties to the south. A small footprint does not change that, so a small house on a frost wall costs proportionally more in foundation than a large one. A slab on grade is permitted where the soil is sand or pit-run sand and gravel to that depth.

Balanced ventilation, even in a small house

The Minnesota residential energy code requires a balanced mechanical ventilation system in every new dwelling, sized by a formula in Minnesota Rules part 1322.0403: 0.02 cubic feet per minute per square foot of conditioned space plus 15 for each bedroom and one more, with a continuous rate of at least 40. In a small plan that usually means a compact heat or energy recovery ventilator, and it needs a closet, not a corner of the loft.

The tiny-house rules are in the state code

Under 400 square feet, Minnesota's own tiny-house appendix applies

Minnesota Rules part 1309.0010 deletes every appendix of the model residential code except two, and Appendix Q, Tiny Houses, is one of them: it is listed with the mandatory chapters that any municipality enforcing the State Building Code must administer. The appendix covers a dwelling of 400 square feet or less, not counting lofts. It relaxes ceiling heights to 6 feet 8 inches in habitable space and 6 feet 4 inches in bathrooms and kitchens, and it sets rules for sleeping lofts: at least 35 square feet, at least 5 feet in every direction, reached by a compact stair, ladder or ships ladder. Above 400 square feet, a small barndominium is drawn to the full Minnesota Residential Code like any other house.

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.

Tiny-house cabin with a sleeping loft

16' x 24' / 384 sq ft main floor / sleeping loft over the bath

Kitchen, bath and living space on the main floor, with a sleeping loft over the bath and entry reached by a compact stair. At 384 square feet it falls under Appendix Q of the Minnesota Residential Code, so the loft can use the appendix's reduced loft dimensions and guard heights. The entry gets a small closed vestibule even here.

One-bedroom cottage with a mudroom

24' x 32' / 768 sq ft living / 1 bed, 1 bath

One bedroom with its own egress window, one bath, an open kitchen and living room under a vaulted steel roof, and a mudroom with laundry at the side entry. The mechanical closet sits between the bath and the mudroom so the water heater, ventilator and radon vent stay together.

Two-bedroom home with an attached heated bay

30' x 36' / 1,080 sq ft living / 24' x 30' heated bay under one roof

Two bedrooms at one end, kitchen and living at the other, and a heated garage or shop bay at the gable end under a continuous roof. The entry from the bay comes through the mudroom, never into a bedroom, and the common wall carries the garage fire separation the Minnesota Residential Code requires.

Ways to build this

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

Barndominium Kits

Barndominium kits and shell kits for Minnesota land, sized to your county's state-set snow load and frost depth, with the drawings your permit needs.

Custom Plans

Custom barndominium plans drawn for Minnesota: your layout and shop, your county's snow load and frost depth, and a set ready for plan review.

Pole Barn Homes

Pole barn homes in Minnesota: pole barn house kits and plans sized to your county's snow load, with posts and footings set below the state frost depth.

Small Barndominium: common questions

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

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What counts as a small barndominium?

There is no legal definition. Most small barndominium floor plans run from about 400 to 1,200 square feet of living space, often with a garage or shop bay under the same roof. The one size line the Minnesota code draws is 400 square feet: at or under that, not counting lofts, the house is a tiny house under Appendix Q of the Minnesota Residential Code, which Minnesota Rules part 1309.0010 keeps in force.

Can I build a small barndominium as a guest cottage on a lake lot?

Sometimes, and small is the point. Minnesota's shoreland rules, Minnesota Rules part 6120.3300, let local shoreland controls allow one guest cottage on a lot that meets the duplex lot size, and cap it at 700 square feet of land surface and 15 feet in height, screened from the water. Whether your county or city allows guest cottages at all is its call, so ask the shoreland administrator before drawing one.

Does a one-bedroom house need a smaller septic system?

The tank, no. Minnesota Rules part 7080.1930 sets 1,000 gallons as the minimum septic tank for any dwelling with three bedrooms or fewer, and 50 percent more if there is a garbage disposal or a sewage pump. The soil treatment area is sized from the design flow and the soils on your lot.

Does a small barndominium still need radon control?

Yes. Minnesota Rules part 1303.2400 requires a passive radon control system in all new one-family dwellings with a basement slab or a slab on grade, which describes nearly every barndominium. That means a gas-permeable layer and a sealed membrane under the slab, and a vent pipe up through the house.

Can a small barndominium go on farm land without a permit?

No. Minnesota Statutes section 326B.121 exempts agricultural buildings from the State Building Code, but section 326B.103 defines those as structures designed and used to house farm implements, livestock or agricultural products. A house is not one. Whether a building permit is issued where you are depends on whether your city, township or county enforces the code, and zoning and septic permits apply either way.

Are small barndominium kits a good fit?

Often. A small, simple rectangle is where a kit shell makes the most sense, because the package matches the plan without much modification. The kit still has to be checked against your county's snow load and frost depth, and the interior, mechanical systems and septic are separate work.

What is the smallest practical footprint?

Below about 16 by 24 feet it gets hard to fit a bath, a kitchen and a usable living space. Under 400 square feet, Appendix Q lets habitable space drop to a 6 foot 8 inch ceiling and bathrooms and kitchens to 6 feet 4 inches; above it, the Minnesota Residential Code calls for 7 feet in habitable rooms, bathrooms and laundry rooms.

Keep reading

The pages that answer the next question this one raises.

How big a barndominium can your budget build?

Where a small plan fits against a real budget, with third-party cost figures.

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30x40 barndominium floor plans

The next size up: 1,200 square feet and room for a third bedroom.

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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 2020 Minnesota State Building Code, in effect since March 31, 2020, and to Minnesota Rules as published by the Revisor of Statutes. The code applies statewide, but whether a building permit is issued and inspected where you build depends on whether your city, township or county enforces it. 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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