Decatur is the seat of Macon County at about 68,000 residents, a central-Illinois city with a large grain-processing and agribusiness base. Building permits are issued by the Building Inspections Division of the city’s Economic and Community Development Department, One Gary K. Anderson Plaza, 3rd floor (217-424-2787), through the city’s OpenGov permit portal, under the city’s home-rule code.
This guide covers the Building Inspections Division, the home-rule code, the grain-processing and industrial base, and how the statewide layers and registration work.
This guide covers work inside the City of Decatur limits. Unincorporated Macon County and neighbouring communities are separate authorities.
Decatur runs its own home-rule Building Inspections Division around a heavy grain-processing and agribusiness base, so large industrial projects run alongside standard permitting. The city issues permits under its own code, with specialised structural and fire review on processing facilities. Confirm the parcel is inside Decatur rather than unincorporated Macon County.
What requires a building permit in Decatur?
Permit required
- New commercial, multi-family and residential construction, additions and change of occupancy
- Structural alterations, load-bearing changes, foundations, decks and retaining walls
- Electrical work — services, panels, circuits, solar and EV charging — under the adopted electrical code
- Plumbing under the statewide Illinois Plumbing Code, tied to a licensed plumber
- Mechanical and HVAC change-outs, and work affecting the energy envelope
- Re-roofing above the exempt scope, pools, signs, and demolition
Often exempt
- Minor repairs and maintenance replacing materials in kind
- Small accessory structures below the local threshold, where zoning allows
- Painting, flooring, cabinetry and other finish work
- Like-for-like fixture or appliance swaps with no alteration to wiring or piping
Because the code edition and its amendments are set locally, the exempt list and thresholds differ from one jurisdiction to the next — a project waved through in one town needs a full permit set in the next. An exemption from a building permit is never an exemption from zoning, the statewide energy or plumbing codes, or an electrical or plumbing permit. Confirm scope with the Building Inspections Division before work starts.
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Get a free quote →The statewide layers that apply everywhere
Three Illinois codes apply statewide: the Illinois Energy Conservation Code, which applies even where a town does not actively enforce it; the Illinois Plumbing Code, from the Department of Public Health, which also licenses plumbers (a local government may adopt a stricter plumbing code, and Chicago has its own plumbing and energy codes and licenses its own plumbers); and the Illinois Accessibility Code. In Decatur, the Building Inspections Division has enforced the 2021 International Building, Residential, Existing Building, Mechanical, Fuel Gas, Fire and Property Maintenance Codes and the 2017 National Electrical Code since January 1, 2024; the statewide Illinois codes apply on top.
Illinois leaves building codes to local government, but since 1 January 2025 any local code must regulate structural design at least as strictly as baseline editions of the International Building, Existing Building and Residential Codes, and where no code was adopted the statute sets minimums for commercial buildings and new homes (Public Act 103-0510). Illinois codes and the statewide baseline
Who handles permitting in Decatur?
The Building Inspections Division handles plan review, permit issuance and inspections inside the city under the home-rule code.
| Detail | Information |
|---|---|
| Authority | City of Decatur Building Inspections Division, One Gary K. Anderson Plaza, 3rd floor (217-424-2787) |
| County | Macon |
| Serves | Work inside the City of Decatur limits |
| Home rule | City sets and amends its own code |
| Base | Grain-processing and agribusiness industry |
| Code | 2021 International Codes and 2017 National Electrical Code (since January 1, 2024), plus statewide Illinois codes |
| Plumbing | Statewide Illinois Plumbing Code and state-licensed plumbers |
| Registration | City licences for electrical and mechanical contractors; plumbing and roofing are state-licensed |
The Building Inspections Division reviews plans, issues permits and inspects construction inside the city under Decatur’s home-rule code. A large grain-processing and agribusiness base drives industrial work with specialised structural, fire and process review, alongside downtown redevelopment and a stable residential base. Unincorporated Macon County is a separate authority, so confirm the parcel first.
The statewide Illinois energy, plumbing and accessibility codes apply on top of the city code, with plumbing tied to a state-licensed plumber.
Not sure this scope needs a permit?
Get a free quote →In 2025, building permits issued in Decatur authorized 3 new privately owned housing units, all of them single-family homes, according to the U.S. Census Bureau Building Permits Survey.
Permit types
Residential permits
Residential work spans established neighbourhoods, infill and renovations. Re-roofs, decks, solar and EV chargers need permits, plumbing is tied to a state-licensed plumber, and electrical and mechanical contractors must hold a City of Decatur licence in good standing.
Commercial permits
Commercial and industrial work runs from grain-processing and agribusiness facilities to downtown and retail, all under the city’s home-rule code and the statewide energy and accessibility requirements, with city-licensed electrical and mechanical contractors and state-licensed plumbers.
Registration, trade licences and design professionals
Practically, three credential layers appear on Decatur projects: City of Decatur licences for electrical and mechanical contractors; state licences for plumbing and roofing; and, on commercial and larger residential work, drawings from an Illinois-licensed design professional. A contractor cannot obtain a permit unless its licence is in good standing.
Illinois licenses plumbers through the Department of Public Health and roofing contractors through the Department of Financial and Professional Regulation; there is no state general contractor or electrician licence, and many jurisdictions require local registration. Contractor credentials in Illinois
Decatur permit costs and fees
Budget the city building permit, separate electrical, plumbing and mechanical permits, and city licences for electrical and mechanical contractors. Decatur charges 0.5% of project value for one- and two-family work (minimum $50) and 0.75% for commercial work (minimum $150), with a $45 re-inspection fee and a $50 continuance fee for an expired permit.
Rather talk it over?
Call 1-855-478-4290 →| Fee component | How it works |
|---|---|
| Building permit | Based on project valuation or square footage; set by the local schedule |
| Plan review | A percentage of the permit fee or a flat charge, at submittal |
| Trade permits | Separate electrical, plumbing and mechanical fees |
| Contractor registration | Local registration fees for the trades pulling permits |
| Zoning and impact | Local zoning review, and impact or capital fees in growth areas |
| Re-inspections and revisions | Additional fees for failed inspections, revisions and expired permits |
Illinois sets one useful certainty in law: once a permit is issued, the code requirements in effect on January 1 of the year you applied govern for the life of that permit, so a mid-project code change will not move the target. Fee schedules, though, are local and change, so a figure from a neighbouring town is not reliable — ask the Building Inspections Division for the schedule in force on your filing date.
Need a real number for a specific Decatur project? Send us the scope, address and valuation and we will identify the authority having jurisdiction, the code edition in force and the fee categories that will apply.
Trade permits and who may pull them
Permit required
- Service installations, panel upgrades, new circuits, solar PV and EV chargers
- New plumbing, repipes, water heater change-outs, fixtures, backflow and gas piping
- HVAC installation and change-out, ductwork, venting and commercial kitchen exhaust
- Sprinkler, standpipe and fire alarm work on commercial and multi-family structures
Typically exempt
- Replacing a fixture, switch, receptacle or light with no alteration to wiring or piping
- Clearing a stoppage without replacing or rearranging concealed piping
- Filter, thermostat and routine component service
- Like-for-like appliance repair that does not alter the connection
Plumbing follows the Illinois Plumbing Code and a licensed plumber (Chicago licenses its own plumbers); electrical and mechanical work follow the locally adopted codes and local licensing or registration. Trade credentials in Illinois
Rather not deal with the building department?
Get a free quote →How to apply for a Decatur building permit
Unincorporated Macon County is a separate authority.
A contractor cannot obtain a permit unless its licence is in good standing.
Grain-processing projects raise structural and fire review.
Plumbing and roofing are state-licensed; electrical and mechanical are city-licensed.
The home-rule code carries its own amendments.
Plan review can take up to 15 business days.
Review, corrections and what actually causes delay
In Illinois, the first cause of delay is uncertainty over jurisdiction and the applicable code edition — filing under the wrong amendments, or with the county when a municipality should have it. After that come missing local contractor registrations, a plumbing scope not tied to a state-licensed plumber, energy-code documentation, and a submittal that did not match what the Building Inspections Division requires. Build the review time into the schedule and confirm the checklist before filing.
A building permit carries a validity period set by Decatur; confirm the expiry on phased or delayed work before it passes. Permit validity in Illinois
Inspections in Decatur
Where a permit is required, standard checkpoints include footing and foundation, framing, rough-in electrical, plumbing and mechanical, insulation and energy, fire systems on commercial work, and final, with a certificate of occupancy before use. Processing and industrial parcels add specialised structural and fire verification.
Illinois is tightening inspector qualifications: from January 1, 2027, those who perform building inspections must hold International Code Council certification, with a grace period after hire. Confirm the notice the Building Inspections Division needs and schedule around its inspection windows.
Want this handled start to finish?
Get a free quote →Do not cover work before the required inspection has been approved. Keep the issued permit, the approved plans, product listings, energy documentation and your correction responses available on site.
Decatur permit search and official resources
Permit records in Illinois sit with the local authority that issued them. Where the Decatur Building Inspections Division is the authority for the City of Decatur limits, it holds the building permit, the inspection history and the certificate of occupancy. If you are buying, refinancing or renovating, confirm that past work was permitted rather than assuming it was — and confirm the code edition that was in force.
Confirm the authority having jurisdiction and the code edition first. Illinois’s local-adoption structure — with the statewide baseline now under it — means the applicable code and amendments vary by parcel. Confirm current requirements, fees and review turnaround for your filing date.
These are the primary sources behind this guide. Codes, fee schedules and procedures change — confirm the position for your filing date.
- City of Decatur, Illinois
- Illinois Capital Development Board (statewide codes)
- Illinois Plumbing Code (IDPH)
- Illinois DFPR (roofing and professional licensing)
- Illinois Office of the State Fire Marshal
Frequently asked questions
Where do I get a Decatur building permit?
From the city’s Building Inspections Division, One Gary K. Anderson Plaza, 3rd floor (217-424-2787), through the OpenGov permit portal, for work inside the city.
Inspections are where schedules slip.
Get a free quote →Is there specialised review for processing plants?
Yes. Decatur’s grain-processing and agribusiness base brings large industrial projects with specialised structural, fire and process review.
Is Decatur’s code its own?
Yes. As a home-rule city, Decatur adopts and amends its own building code; the statewide Illinois codes apply on top.
Is plumbing handled locally?
Partly. Plumbing must meet the Illinois Plumbing Code and be done by a state-licensed plumber, but the city issues the plumbing permit through OpenGov and the Building Inspections Division inspects the work.
Do I register with the city or the county?
Electrical and mechanical contractors are licensed by the City of Decatur for city work; unincorporated parcels file with Macon County.
How do I run a Decatur permit search?
The city holds permit and inspection records for work inside the city.
Simplify Decatur permitting with Alliance Permitting
Decatur runs a home-rule Building Inspections Division around a grain-processing base, so the questions are jurisdiction, specialised industrial review, and city trade licences. Getting those right keeps a central-Illinois project moving.
Trusted by leading builders, developers, and national contractors — 21+ years of filing in the jurisdictions we write about.
Contractors and builders choose Alliance for Decatur because the work is done by people who have stood at the counter:
- We confirm city-versus-county jurisdiction from the parcel.
- We confirm city electrical and mechanical licences.
- We coordinate specialised review on processing work.
- We assemble the plan set to Decatur’s home-rule code.
- We confirm state plumbing and roofing licences and track the review.
Alliance Permitting is a permit documentation and submission company in Illinois. We prepare your paperwork, file it correctly and coordinate with the permitting authority through issuance. We are not a contractor and we do not perform licensed plan review or inspections; that work stays with your licensed team and the jurisdiction.
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More Illinois permitting guides
This guide is provided by Alliance Permitting for general information about Decatur permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.