Illinois Construction Estimating Services

For most of its history, Illinois had no building code. The state let every city, village and county adopt whatever it wanted, and a lot of rural counties adopted nothing at all.

That changed on January 1, 2025. Under the Capital Development Board Act, a statewide code now applies wherever a local government never adopted one: the IBC and IEBC for commercial work, the IRC for houses, the NEC for electrical. If the town already had its own code, it keeps it, but from that same date the local code has to regulate structural design at least as strictly as the IBC for new buildings and the IEBC for existing ones. So a pole barn in a no-code county and a shell in a village with a 20-year-old ordinance are both priced against a real book now. The book is not always the same one. Ask which.

Energy is the opposite story. Illinois has had one statewide energy code for years, and it’s the 2021 IECC with Illinois amendments for permits applied for since late 2022. Every new commercial and residential building follows it, whether the town has a building code or not. Towns can go stricter on commercial. On residential they mostly can’t, with one exception that matters: Chicago, the only municipality over a million people, runs its own.

Then there’s the tax. In Illinois, the contractor is the end user. You don’t collect sales tax from the owner on a construction contract. You pay use tax on the cost of the materials you build in, either to your supplier or straight to the Department of Revenue. That means the tax lives inside your material lines, not on a separate line at the bottom of the proposal. Price it there or eat it.

Every one of these has cost somebody real money. We see them monthly.

1. Which code the drawings were stamped to. With a statewide floor in place since January 2025, the question on every job is whether the site sits under a local code or the state default, and whether an existing building is being looked at through the IEBC. The two paths give you different structural scopes for the same square footage. If you price a downstate remodel like a Naperville remodel, you’re going to find the difference on the plan-review comments.

2. The energy code, on every job. The 2021 IECC is the statewide minimum and it doesn’t care whether the village has a building department. Envelope, glazing, lighting controls and commissioning are in the number or the number is wrong. Chicago’s own energy rules sit on top of that inside the city.

3. Accessibility is a state code, not IBC Chapter 11. Illinois deliberately left Chapter 11 out of its statewide IBC adoption, along with Chapters 13 and 29, because it runs its own codes for each: the Illinois Accessibility Code, the energy code and the Illinois Plumbing Code. The Accessibility Code covers public facilities and multi-story housing and every space inside them. Take the ADA checklist you use in another state and you’ll miss items the Illinois plan reviewer is going to flag.

4. Use tax in the material lines. Because the contractor pays the tax on materials and collects nothing from the owner, an estimate that carries tax as a lump percentage at the end is quoting the wrong job. It belongs in the unit cost of every stick, sheet and fixture. Sell material without installing it and you’re back to collecting retailers’ occupation tax, which is a different filing again.

We don’t ask you to take our word for it. Sixteen real Illinois estimates are on this page, four in each of the four categories we work in. $50.6M of construction value across 115 pages of takeoff and pricing. Open them. Read the line items. See exactly what you get before you send us a single sheet.

Commercial Buildings — ground-up industrial, retail, institutional and financial.

• Truck Maintenance Facility, Joliet – $6.5M (60436)
• Nature Institute, Godfrey – $3M (62035)
• Mid America Credit Union, Springfield – $2.4M (62702)
• North Chicago Starbucks – $2.2M (North Chicago 60064)

Multi Family and Apartments — apartments, condos and multi-unit housing.

• Darien Height, Darien – $16M (60561)
• 3211 S Archer Ave, Chicago – $5.4M (60608)
• 4-Story Masonry Building, Chicago – $1.9M (60609)
• Park Bloomingdale Condominiums – $1.2M (Bloomingdale 60108)

Residential — custom homes and whole-house remodels.

• Midwest Club, Oak Brook – $4.3M (60523)
• 185 Wagner Rd, Winnetka – $2.2M (60093)
• 747 Rogers Street Remodel, Downers Grove – $889K (60515)
• Grantley Ave, Elmhurst – $462K (60126)

Tenant Buildouts — interior fit-outs in existing buildings.

• VASA Fitness, Matteson – $1.9M (60443)
• University Mall Outlot, Carbondale – $1.3M (62901)
• Beauty and the Bakery – Buildout & Addition, Westmont – $750K (60559)
• First Watch, Crystal Lake – $185K (60014)

Four building types. The North Shore down to the south suburbs, Springfield and the Metro East, and all the way to Carbondale. From a $185K restaurant fit-out to a $16M apartment building. That range is the whole point. Most shops price one lane and call it a service.

Look at the Oak Brook house. $4.3M, seventeen pages, and a big share of those pages are finishes: millwork, tile, a pool wall, heated floors, motorized screens. A custom home at that level is a finishes takeoff with a foundation under it, and every one of those items got counted, not allowed for.

Same idea on the Carbondale outlot. $1.3M, eleven pages, a national tenant’s fit-out with the landlord’s work split out from the tenant’s and the tenant’s required vendors carried where the drawings put them. That split is where a TI estimate lives or dies.

We estimate statewide. Here’s where the volume actually is.

Chicago. The city keeps its own building code and its own energy code, and both of the Chicago jobs on this page, the Archer Avenue building and the four-story masonry building, sit inside city limits. Bridgeport, Pilsen, the South Side, the North Side, the Loop.

The suburbs. Oak Brook, Elmhurst, Westmont, Downers Grove, Darien, Bloomingdale, Naperville, Schaumburg and Joliet on the west and southwest; Winnetka, Evanston, Libertyville, North Chicago and Crystal Lake on the north; Matteson and the south suburbs. Thirteen of the sixteen estimates above are Chicago-area jobs, and no two of those building departments read a set of drawings the same way.

Rockford and the north. Rockford, Belvidere, DeKalb and Freeport. Long hauls for Chicago subs, which shows up in your durations.

Springfield and central Illinois. Springfield, Chatham, Decatur, Champaign-Urbana, Bloomington-Normal and Peoria. The Mid America Credit Union is a Springfield job.

The Metro East. Godfrey, Alton, Edwardsville, Belleville and Collinsville, across the river from St. Louis. The Nature Institute is here.

Southern Illinois. Carbondale, Marion, Mt. Vernon and Effingham. The University Mall outlot is a Carbondale job. This is also where the statewide code matters most, because it only applies where a local one was never adopted, and rural counties are where that’s most likely.

Every one of those cities has its own page with local detail. Start there if you want the county-level specifics.

General contractors bidding hard-bid and negotiated work. Subs who need a takeoff that survives a scope review. Developers who want a real number before they commit capital. Architects who’d rather price a design now than explain a surprise at bid day.

Illinois added 12,700 construction jobs in the year to July 2026, fifth-most of any state, and added more jobs than any state in July alone. If you’re a GC in Illinois turning down invitations because you can’t get numbers out fast enough, you’re going to keep leaving work on the table until somebody else does the takeoff for you. That’s what our Illinois construction estimating services are built to fix. You send the plans. We send back a priced estimate with the quantities shown, in a format you can hand straight to a client or an owner.

We’re not a lead service and we’re not a software subscription. A person does the takeoff. Another person checks it. You can call and ask why a number is what it is, and get an answer.

What you’re hiring is a cost estimator who has already priced work under your town’s code, under the state’s energy code, with the use tax where it belongs. Not a national square-foot average with the word Illinois written on top.

Send us your plans. We’ll tell you what it costs.