Barndominium floor plan and elevation drawings laid out on a drafting table with a scale rule.

Custom Plans in Illinois

Barndominium plans are easy to find and hard to build from as bought. A stock plan does not know your lot, your county's snow load or frost line, where the septic field has to go, or what your building department wants on paper. We draw custom barndominium plans from scratch and modify stock barndominium floor plans you already like, then tie them to the kit and build quote so the drawings, materials list and price all describe the same house. Most Illinois homes do not need an architect: the Illinois Architecture Practice Act does not require one for a detached single-family residence on a single lot unless a local ordinance does. Where your county does require sealed drawings, as unincorporated Will County does for every new one- and two-family residence, a third-party licensed Illinois design professional reviews and seals the set. You get plans drawn to build, not to browse.

Permit-ready drawings
Plans checked against your local code
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Custom Plans: how the work runs

Four stages, in this order. The sequence matters more than it looks: getting the structural design and permitting settled before anything is fabricated is what keeps a build from stalling.

1

Start from a stock plan or a blank page

Bring barndominium floor plans you like, a sketch, or just a list of rooms and a shop size. We work out the footprint, the living and shop split, porches, garage or shop bays and ceiling heights, and turn that into a first layout you can mark up.

2

Check the lot and the jurisdiction

Before the plan is finalised we confirm who issues the permit for your parcel and what they publish: code edition, frost depth, snow load and any sealed-drawing rule. Code editions differ between neighbouring counties; Kendall County adopted the 2024 International Residential Code effective May 11, 2026, while Will and Peoria counties use the 2018 edition.

3

Draw custom barndominium plans to build

We produce the working set: floor plans, elevations, sections, foundation layout and the details the kit and trades build from. The septic reserve area and well location are kept clear of driveways and slabs on the site plan, and the plan carries the passive radon pipe every new Illinois home requires.

4

Seal, submit and price

Where your building department requires sealed documents, a licensed Illinois design professional reviews and seals the set. The same drawings then drive the kit order and the build quote, so there is one set of numbers from permit to finish.

Overhead view of architectural floor plan and structural elevation drawings spread on a workbench with a scale ruler and pencil.
Plans that match the permit

A barndominium plan is only finished when your building department accepts it

What the plan set must show depends on where you build. Illinois leaves residential permits to cities, villages and counties, and their requirements differ. Unincorporated Will County requires documents signed and sealed by a registered design professional for all new one- and two-family residences. McHenry and DeKalb counties require a seal for pier-supported roofed structures attached to a house. McLean County asks for architect or engineer plans only on commercial work, not homes. And the Capital Development Board says residential projects do not typically require a licensed design professional where the local government does not issue permits. We find out which rule applies to your parcel first, then draw to it.

Where we deliver custom plans

We deliver custom plans across Illinois, from the collar counties outside Chicago to Rockford, the Quad Cities, Peoria, Bloomington-Normal, Champaign, Springfield, Quincy, the Metro East and Southern Illinois. Cross a city or county line and what can change is who reviews the drawings, what they charge, and how the land is zoned, so we confirm the authority for your parcel first.

Serving clients across Illinois.

Every locality we build in has its own reviewer and its own fee schedule. The location pages set out who issues the permit in each one.

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Before you commit

What actually decides the price

Square footage is the number everyone leads with, and it is rarely the one that moves a barndominium budget. These four do.

  • Custom from scratch or a modified stock plan

    Modifying barndominium floor plans you already have is usually quicker than a blank-page layout. Moving a wall is small; changing spans, roof lines or the shop-to-living split reworks most of the set.

  • Whether your county requires a seal

    Unincorporated Will County requires sealed documents for every new one- and two-family residence, and some counties require a seal only for pier-supported structures. When a seal is needed, a licensed Illinois design professional's review and seal becomes part of the plan cost and schedule.

  • Level of detail

    A permit set for a county that reviews plans needs foundation, framing and section details. A set for a place with no adopted code still needs to name the residential code the house is built to, because the Illinois Residential Building Code Act puts that in the contract. More detail costs more up front and saves questions on site.

  • Site plan and lot constraints

    Septic reserve areas, well setbacks, accessory height caps and density rules can move the house. Kendall County generally allows one home per 40 acres of agriculturally zoned land, and Champaign County caps residential accessory buildings at 24 feet on lots of an acre or more. Fitting the plan to those limits takes time before drawing starts.

Barndominium floor plan and elevation drawings laid out on a drafting table with a scale rule.

Custom Plans in Illinois: common questions

8 questions we get asked most often about building in Illinois. If yours is not on the list, ask it directly.

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Do I need an architect for barndominium plans in Illinois?
Usually not. The Illinois Architecture Practice Act does not require an architect for a detached single-family residence on a single lot, unless a local ordinance requires one. Some building departments still require sealed drawings: unincorporated Will County does for all new one- and two-family residences. Where that applies, a licensed Illinois design professional seals the plans.
Can you modify barndominium floor plans I found online?
Yes. Many clients bring a stock plan they like. We adjust the layout, shop size, porches and openings, then check it against your county's published design figures and redraw the set so it can be permitted and built.
How are custom barndominium plans different from stock plans?
Custom barndominium plans start from your lot, your rooms and your shop needs. Stock plans are drawn for no site in particular, so they skip the frost depth, snow load, septic layout and sealed-drawing rules that vary from county to county in Illinois.
Do the plans account for snow load and frost depth?
Yes, using the figures your jurisdiction publishes. Peoria County publishes a 20 psf ground snow load and a 42-inch frost line; McHenry and Kane counties publish 30 psf and 42 inches. The plan is drawn to your county's numbers, not a single state figure, because Illinois does not set one.
Do you have shouse plans?
Yes. Shop-and-house layouts are one of the most common requests. Before settling shop height, check the local cap: Madison County's zoning limits accessory buildings to 25 feet in its agricultural and conservation districts and 20 feet in residential districts, and a tall shop bay can run into rules like that.
What if my county has no building code?
Then there is no plan review, but there is still a code. Under the Illinois Residential Building Code Act, a contract for a new home in a place with no local code must name the residential code it will be built to; if it names none, the current International Residential Code, the Illinois Energy Conservation Code and the Illinois Plumbing Code apply by law. The plans are drawn to that code.
Can the plans be used with a kit?
Yes, that is the point of drawing them here. The same set drives the kit order, the foundation layout and the build quote, so nothing is re-drawn when the steel or timber is ordered.
Do the plans include the energy code?
Yes. The Illinois Energy Conservation Code applies to new homes across the state, currently the 2024 IECC with Illinois amendments, in effect since November 30, 2025. Wall and roof assemblies in the plan set are drawn to meet it.

Keep reading

The pages that answer the next question this one raises.

Is It Legal in Illinois?

Whether a city, a village or the county issues your permit, and what each one decides.

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Floor Plans

Starting points by footprint and by feature, before anything is drawn from scratch.

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Permitting

What the finished set has to contain for a complete submittal.

Read it

Ready to put custom plans against a real plan? Start there and the rest follows.

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Tell us about the land

Send the parcel ID or an address and we will come back with what can be built on it, who issues the permit, and a realistic budget range. That conversation costs nothing.

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