40' x 60' · 2,400 sq ft footprint

40x60 Barndominium Floor Plans in Illinois

The 40x60 is the most requested size in barndominium floor plans because 2,400 square feet does two jobs well. As a full house it holds three or four bedrooms, an open great room and a real pantry and mudroom. As a shop-house it gives a two-door shop and a three-bedroom living end under one roof. A 40-foot clear span is still an ordinary truss or rigid-frame span, so the interior stays free of bearing walls. What drives a 40x60 plan is the split between living and shop, the wall height, the foundation below your county's frost line, and whether your county asks for sealed drawings on a new home. In Illinois those rules come from the city, village or county, not the state, and they vary from one county line to the next.

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What actually changes at this size

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

A 40-foot clear span with no interior bearing walls

Trusses or steel rafters spanning the full 40 feet leave every interior wall free to move, which is what lets a 40x60 carry a large open great room with a vaulted ceiling down the middle. The trusses are designed to the ground snow load your jurisdiction publishes: Peoria County lists 20 pounds per square foot for unincorporated homes, and McHenry and Kane counties list 30. A kit designed for one county is not automatically right for another.

Three or four bedrooms as a full house

As an all-living plan, a 40x60 fits four bedrooms and three baths with a split layout: the primary suite at one gable end, the other bedrooms at the far end, and the kitchen, dining and living room in between. A walk-in pantry, a mudroom off the garage door and a laundry room all fit without squeezing. Many buyers keep one bedroom as an office.

Two shop doors or a three-car bay in the split plans

Giving 20 feet of the length to shop produces a 40x20 bay with two overhead doors, or one wide door and a man-door. A 14-foot sidewall allows a 12-foot door for a tall pickup or a small tractor. If the building sits under a height cap, check it before choosing the wall: Madison County's zoning booklet caps accessory buildings at 20 feet in residential districts and 25 feet in agricultural ones, and Champaign County's zoning ordinance allows 24 feet on lots of an acre or more.

Foundation and footings to the county's frost depth

Posts, piers or a monolithic slab edge must reach below the frost line your county publishes. McHenry, Kane, Will, DeKalb, Winnebago, Rock Island and Peoria counties each list 42 inches for unincorporated areas, and Tazewell County's garage handout lists 36. Peoria County also assumes a soil bearing value unless a test shows otherwise, which is one reason a soil test before the slab is worth the time on a 2,400-square-foot footprint.

Size and sealed plans

At 2,400 square feet the plan is easy; the county's paperwork is what differs

A 40-foot span and 2,400 square feet are well within what post-frame and steel suppliers design every day, so the structure rarely limits the layout. What changes from one county to the next is how much documentation the building department wants. Will County requires every new one- or two-family residence to have documents signed and sealed by a registered design professional, or as its chief building official approves. McLean County's permit guidance asks for plans certified by an architect or engineer only on commercial, manufacturing and church work, not houses. Champaign County issues zoning use permits and, in a 2012 county study, said it had not adopted a building code. Where a county has no building code, the Illinois Residential Building Code Act requires the new-home contract to name the code the house will be built to, and if the contract names none, the current International Residential Code applies by law (815 ILCS 670/15).

How people actually split 2,400 sq ft

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

Four-bedroom family house

2,400 sq ft living

A split-bedroom layout with the primary suite and walk-in closet at one end, three bedrooms and two baths at the other, and a 40-foot-wide great room, kitchen and dining area in the middle. Add a covered porch on a long sidewall and an attached or detached garage, and it is a full family home.

Three-bedroom home with a two-door shop

800 sq ft shop / 1,600 sq ft living

A 40x20 shop with two overhead doors at one end and a 40x40 living area with three bedrooms and two baths. The shared wall between shop and house needs a fire-separation detail and should sit on a frame line. This is the most popular 40x60 barndominium plan for buyers on acreage who want the shop and the house under one roof.

Shop-forward with a compact home

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

An even split: a 40x30 shop large enough for equipment or a trailer, and a 40x30 living end with two bedrooms and two baths. It suits a working property or a trade business run from home. On a mainly residential lot, confirm with the zoning office how the county treats a shop this large beside the home, and whether any business use needs a separate approval.

Ways to build this size

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

Custom Plans

Custom and modified barndominium plans drawn for your Illinois lot, your county's code and the kit or build we quote — sealed where your county requires.

Shouses

Shouse and shop house builds in Illinois: a heated shop and a finished home under one roof, planned around your doors, your county and your land.

Pole Barn Homes (Post-Frame)

Pole barn homes built post-frame for Illinois acreage: wide clear spans, fewer footings, and posts and footings set to your county's rules.

Turnkey Builds

One contract from land to keys. We coordinate permits, septic, well, site work, shell and finish for your barndominium anywhere in Illinois.

40x60 Barndominium: common questions

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

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How many bedrooms fit in a 40x60 barndominium?

Four bedrooms and three baths fit comfortably when the whole 2,400 square feet is living space. With an 800-square-foot shop at one end, the remaining 1,600 square feet carries three bedrooms and two baths. With an even split, plan on two bedrooms. The 40-foot span keeps every one of these layouts free of interior bearing walls.

Do 40x60 barndominium plans need an architect's or engineer's seal?

Not by state law for a detached single-family home on a single lot, unless a local ordinance requires it (225 ILCS 305/3). Some counties do require one. Will County requires signed and sealed documents for every new one- or two-family residence. McHenry and DeKalb counties require a seal for pier-supported roofed structures attached to a house, such as a post-frame garage or porch. Where your county requires it, a licensed Illinois structural engineer seals the drawings.

What building code applies to a 40x60 barndominium in Illinois?

Whatever your city, village or county has adopted, and editions vary widely. Kendall County adopted the 2024 International Residential Code effective 11 May 2026; McHenry, Kane and DeKalb counties use the 2021 edition; Will, Peoria and Tazewell counties use 2018; and Winnebago County still lists 2015. Since January 1, 2025, any code a city, village or county adopts must regulate structural design at least as strictly as the International Residential Code (20 ILCS 3105/10.18). The Illinois Energy Conservation Code applies to new homes statewide.

Is a 40x60 better as a house or as a shop-house?

It depends on the land and on what the building has to do. If a separate garage or shop is planned later, the full-house layout gives the best bedroom count and resale. If you need a shop now and want one roof, one foundation and one set of utilities, the 1,600 / 800 split is the usual choice. The shop-forward even split makes most sense on a working property.

What drives the cost of a 40x60 barndominium?

The interior finish level, the foundation, and the site work. Shell and frame costs scale with the footprint, but finishes such as cabinets, flooring, tile and fixtures are where two 40x60s built on the same frame end up far apart. Site work is fixed by the land: the driveway, power run, well, and a septic system designed from a soil investigation with at least three borings (77 Ill. Adm. Code 905.55). We price each project from your drawings and your site.

Does a 40x60 barndominium need a septic permit?

Yes, where it is not connected to a public sewer. Septic systems are designed to the Illinois Department of Public Health's Private Sewage Disposal Code, and the permit usually comes from the county health department: the Tazewell County Health Department and the Rock Island County Health Department's environmental division both approve septic plans for their counties. Madison County permits private sewage systems only on lots of at least 40,000 square feet. Keep the driveway and shop apron off the seepage field area, because the code requires that area to stay free of driveways, accessory buildings and slabs.

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

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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, who issues the permit, and a realistic budget range. That conversation costs nothing.

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