A building permit submittal package on a desk with rolled construction drawings, forms on a clipboard, and a hard hat.

Permitting & Approvals in Illinois

Illinois does not issue residential building permits. Your city, village or county does, if it has adopted a building code, and the answer changes at every city limit and county line. We take the permitting off your plate. For each barndominium we identify who has authority over your parcel, which code and edition they enforce, and what they will ask for: zoning approval, plan review, sealed drawings, inspections, an occupancy permit, or only a zoning or filing permit. We prepare and submit the building application, coordinate the septic permit and the well permit with the health department, and schedule inspections as the build moves. Where no local building code applies, your contract names the residential code the home is built to, as Illinois law requires for new homes. Either way, the house is built to a named code and the Illinois Energy Conservation Code, and you have the paperwork a lender or insurer will ask for.

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Plans checked against your local code
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Permitting & Approvals: 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

Find who has authority over your parcel

We start with the parcel, not the county name. Inside a city or village, the municipality's own code and building department apply. In unincorporated territory the county decides whether it has a building code at all, and the answer varies widely: McHenry and Kane counties enforce the 2021 International Residential Code, Kendall County the 2024 edition from May 11, 2026, while Champaign County's department issues zoning use permits and Williamson County's ordinance has permits filed with the Supervisor of Assessments.

2

Clear zoning and land-use rules first

Zoning can stop a project before the building code is reached. Illinois counties may set a minimum lot size for homes on land used for agriculture (55 ILCS 5/5-12001), and some are strict about it; Kendall County generally allows one home per 40 acres of agriculturally zoned land. We confirm the district, setbacks, height limits and any lot-size rule before design is final.

3

Barndominium permit application and plan review

We assemble the drawings, site plan, energy code documentation and any other items the jurisdiction lists, and submit the application. Where sealed drawings are required, as Will County requires for every new one- and two-family residence, a licensed Illinois structural engineer prepares and seals them. We answer plan-review comments and keep the septic and well approvals moving alongside.

4

Inspections, sign-off and your records

We schedule each inspection the jurisdiction requires as the build reaches it, and meet the inspector on site. Where the county requires an occupancy permit, we close it out. At the end you receive the permits, approvals and the code the home was built to in one file, which is what lenders, appraisers and insurers ask for.

Overhead view of architectural floor plan and structural elevation drawings spread on a workbench with a scale ruler and pencil.
Who issues the permit?

Illinois sets the floor. Your city, village or county decides the rest.

Illinois does not issue residential building permits and does not inspect private homes; the Capital Development Board says those tasks, where they are required, belong to the unit of local government. Cities, villages and counties decide whether to adopt a building code. Since January 1, 2025, any code a city, village or county adopts in Illinois must regulate structural design at least as strictly as the International Residential Code (20 ILCS 3105/10.18). Where no local building code applies, the Illinois Residential Building Code Act requires the contract for a new home to name the residential code it will be built to; if the contract names none, the current International Residential Code, the Illinois Energy Conservation Code and the Illinois Plumbing Code become part of the contract by law (815 ILCS 670). Chicago has its own Chicago Construction Codes, and unincorporated Cook County has its own Department of Building and Zoning. Neither is the Illinois rule. So there is no single answer to "what permit do I need", only the answer for your parcel, and that is where we start.

Where we deliver permitting & approvals

We deliver permitting & approvals 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.

  • Which jurisdiction you are in

    A lot inside a city or village, an unincorporated lot in a county with a full residential code, and a rural parcel in a county that issues only a zoning permit are three different permitting jobs. Plan-review depth, the number of inspections and the local fee schedule all follow from which one your parcel falls under.

  • Whether sealed drawings are required

    Illinois does not require an architect for a detached single-family home unless a local ordinance does, and the Capital Development Board notes that residential projects do not typically require a licensed design professional. Some counties do require seals: Will County for every new residence, Kane County for pier-supported detached accessory buildings. Where a seal is needed, a licensed Illinois structural engineer adds a line to the budget.

  • Farmland, zoning and lot size

    Building on agricultural land can mean a rezoning, a variance or a lot split before a building permit is possible, because counties may set a minimum lot size for residences on farmland. Each of those steps adds time, hearings and fees. Checking the zoning before you buy land is the cheapest permitting decision you will make.

  • Septic, well and road approvals

    The septic permit needs a soil investigation with at least three borings before the system can be designed (77 Ill. Adm. Code 905.55), and a new well needs its own permit before drilling (77 Ill. Adm. Code 920.130). A new driveway entrance may need the road authority's approval. These run alongside the building permit and are often what sets the start date.

A building permit submittal package on a desk with rolled construction drawings, forms on a clipboard, and a hard hat.

Permitting & Approvals 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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Are barndominiums legal in Illinois?
Yes. A barndominium people live in is a single-family home, and Illinois law treats it as new residential construction like any other house. What decides whether you can build one on a particular parcel is local: the zoning district and any minimum lot size, the building code your city, village or county enforces, and the septic and well permits from the health department.
Can you have a barndominium in Illinois on farmland?
Usually, but it is still a house. Counties cannot require permits for buildings used for agricultural purposes on farmland, but the same statute lets them set a minimum lot size for residences on agricultural land (55 ILCS 5/5-12001). A barndominium you live in is a residence under county zoning, so the district rules and any lot-size minimum apply to it.
Who issues barndominium permits in Illinois?
Your city, village or county, if it has adopted a building code. The State of Illinois does not issue residential building permits or inspect private homes. Inside a municipality the city or village issues the permit. In unincorporated areas the county does, and its role ranges from full plan review and inspections to a zoning use permit only.
Do I need a building permit if my county has no building code?
You may not need a building permit, but you still build to a code. Where no local building code applies, Illinois law requires the new-home contract to name a residential code, and if it names none the current International Residential Code, the Illinois Energy Conservation Code and the Illinois Plumbing Code apply by law (815 ILCS 670). Zoning, septic and well permits still apply.
Are barndominiums on farms exempt from the building code?
Sometimes the house itself is, but less often than people think. Illinois lets county building codes exclude farm residences on farms, and Tazewell and Williamson counties both exclude them. That exclusion depends on a working farm, not just rural land, and it never removes the energy code, the plumbing code, zoning, or the septic and well permits. A non-farm buyer building on former cropland is building an ordinary house.
What about Chicago and Cook County?
Both have their own rules. The City of Chicago issues permits through its Department of Buildings under the Chicago Construction Codes, and unincorporated Cook County has its own Department of Building and Zoning, which adopted provisions of the 2021 International Residential Code. Neither applies anywhere else in Illinois, and inside a Cook County suburb the village's own building department issues the permit.
Does the energy code apply to a barndominium in Illinois?
Yes, to the living space. The Illinois Energy Conservation Code applies to new homes across the state, and the current edition is the 2024 IECC with Illinois amendments, in effect since November 30, 2025 (Capital Development Board). Where no local government enforces it, the Board says you must still comply even though it may not be enforced. An unconditioned shop area is treated differently from heated living space.
How long does barndominium permitting take?
It depends almost entirely on the jurisdiction and on how many approvals your parcel needs. A lot that is already zoned for a home, with soil suited to a septic field, moves quickly; a farm parcel that needs a lot split or rezoning, or a county with detailed plan review, takes longer. We map the approvals at the start so you know the sequence before you close on land.

Keep reading

The pages that answer the next question this one raises.

Is It Legal in Illinois?

Which body sets the rules for your parcel, and where the agricultural exemption stops.

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How Long Does It Take?

Where plan review sits in the schedule, and what slows it down.

Read it

Where We Build

Which authority actually reviews your parcel, city by city.

Read it

Ready to put permitting & approvals 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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