Short answer
Illinois had 29,457 construction establishments with paid employees in 2023, employing 229,716 people with $20.73 billion in payroll, according to Census County Business Patterns. That's 3.62% of the US total and 5th among states; Cook County alone had 10,711. Average pay was $90,240, fourth-highest among states. Illinois licenses plumbers and roofing contractors, not general contractors, and IDOT publishes a weekly list of 580 prequalified highway contractors.
- 29,457 construction establishments and 229,716 employees in Illinois in 2023, 5th among states by establishments.
- Average construction pay of $90,240 is fourth among states and DC, behind Alaska, Massachusetts and Minnesota.
- The Illinois counties of the Chicago metro hold 72.0% of the state's construction establishments.
- IDOT's prequalified contractor directory, compiled 26 October 2026, lists 580 firms, 459 with Illinois addresses, plus 821 registered subcontractors.
- Illinois licenses plumbers (IDPH) and roofing contractors (IDFPR); general contractors are licensed locally, as in Chicago.
On this page
This report is for anyone looking at construction companies across Illinois: owners and public agencies looking for a contractor, primes looking for subcontractors, researchers, job seekers and B2B sellers planning a statewide territory. For the city itself, see the Chicago construction companies report, which covers the city's general contractor license classes and permit data.
Illinois construction by the numbers
County Business Patterns (CBP) 2023, construction sector (NAICS 23), State of Illinois:
| Measure | Illinois, 2023 |
|---|---|
| Construction establishments | 29,457 |
| Employees | 229,716 |
| Annual payroll | $20,729,668,000 |
| Average employees per establishment | 7.8 |
| Average annual pay | $90,240 |
| Share of US construction establishments | 3.62% (of 814,557) |
| Rank among states by establishments | 5th |
Two numbers stand out. Illinois establishments average 7.8 employees, below the US average of 9.4, and they pay $90,240 a year on average, against $76,580 nationally. Only Alaska ($102,958), Massachusetts ($92,804) and Minnesota ($91,833) pay more.
| Employees per establishment | Establishments |
|---|---|
| 1 to 4 | 21,381 |
| 5 to 9 | 3,653 |
| 10 to 19 | 2,204 |
| 20 to 49 | 1,454 |
| 50 to 99 | 479 |
| 100 to 249 | 215 |
| 250 to 499 | 51 |
| 500 to 999 | 12 |
| 1,000 or more | 8 |
In bands: 27,238 establishments (92.5%) have 1 to 19 employees, 1,933 have 20 to 99 and 286 have 100 or more. Nearly three-quarters, 21,381, have fewer than five.
How CBP counts. Each location with a payroll in the week of March 12, 2023 is one establishment, so a company with five yards counts five times. Self-employed contractors without payroll aren't counted, and firms based in Indiana, Wisconsin or Missouri working Illinois jobs are counted in their home state.
Chicago and the rest
| Area (Illinois counties only) | Establishments | Employees |
|---|---|---|
| Chicago metro | 21,211 | 164,832 |
| St. Louis metro (Metro East) | 1,418 | 13,827 |
| Peoria metro | 758 | 7,632 |
| Rockford metro | 657 | 4,810 |
| Springfield metro | 435 | 3,424 |
| Champaign-Urbana metro | 427 | 3,647 |
| Counties outside any metro or micro area | 1,352 | 7,664 |
| County | Establishments | Employees |
|---|---|---|
| Cook | 10,711 | 78,923 |
| DuPage | 3,051 | 31,454 |
| Lake | 1,998 | 12,422 |
| Will | 1,900 | 16,947 |
| Kane | 1,655 | 13,329 |
| McHenry | 1,148 | 7,214 |
| Madison | 560 | 7,265 |
| Winnebago | 538 | 3,966 |
| St. Clair | 433 | 4,185 |
| Sangamon | 404 | 3,350 |
DuPage County's contractors average 10.3 employees, against 7.4 in Cook, so many of the region's larger firms are based in the suburbs. Madison County, across the river from St. Louis, averages 13.0.
Trades and builders
| Type of work (NAICS) | Establishments | Employees |
|---|---|---|
| Specialty trade contractors (238) | 18,685 | 153,878 |
| Electrical, plumbing and HVAC (2382) | 7,103 | 79,478 |
| Building finishing (2383) | 4,734 | 26,545 |
| Foundation, structure and exterior (2381) | 4,128 | 28,393 |
| Other specialty, including site preparation (2389) | 2,720 | 19,462 |
| Building construction (236) | 9,565 | 46,149 |
| Residential building (2361) | 8,062 | 22,729 |
| Commercial and institutional building (236220) | 1,315 | 20,515 |
| Heavy and civil engineering (237) | 1,207 | 29,689 |
| Utility systems (2371) | 576 | 16,406 |
| Highway, street and bridge (2373) | 359 | 9,211 |
Mechanical and electrical contractors employ 34.6% of the state's construction workforce. Residential builders are the smallest firms, averaging 2.8 employees; heavy and civil firms average 24.6.
The IDOT lists: prequalified contractors and subcontractors
IDOT makes prequalification a mandatory step for firms that want to work as its contractors, and it posts the results as plain-text directories:
| IDOT directory (compiled 26 October 2026) | Firms | With an Illinois address | Updated |
|---|---|---|---|
| Prequalified contractors | 580 | 459 | Every Monday |
| Registered subcontractors | 821 | 681 | Every Monday |
Each prequalified entry gives the firm's name, prequalification number, address, phone and work category codes; each subcontractor entry lists its work categories (earthwork, drainage, guardrail, landscaping and so on) and an expiration date. Between them, they're the most complete free list of highway and heavy civil contractors in the state. IDOT also publishes a directory of certified disadvantaged business enterprise (DBE) firms.
The Census Bureau's Building Permits Survey shows the residential side: 18,551 housing units authorized in Illinois in 2025, against 20,326 in 2024. Single-family units rose from 10,326 to 10,821, while units in buildings of five or more fell from 8,771 to 6,267.
What Illinois licenses
| Who | State requirement | Agency |
|---|---|---|
| Plumbers, plumbing contractors, apprentices, irrigation contractors | Plumbers are licensed under the Illinois Plumbing License Law; any licensed plumber working for others must register annually as a plumbing contractor and carry liability and workers' compensation insurance | Illinois Department of Public Health (IDPH) |
| Roofing contractors | State roofing contractor license, with a qualifying party | Illinois Department of Financial and Professional Regulation (IDFPR) |
| General contractors, electricians, HVAC contractors | Not on IDFPR's list of regulated professions | Licensed locally where required; Chicago runs five general contractor classes |
| Highway contractors | IDOT prequalification | Illinois Department of Transportation |
So the first question to ask an Illinois contractor is where it's licensed: by the state for plumbing or roofing, and by the city or village for general contracting and electrical work.
Public companies
EDGAR's only Illinois-addressed registrant in the construction SIC codes is BOXABL Inc. of Itasca, but that filer was FG Merger II Corp., a blank-check company with no operations through 2025; it completed its merger with Boxabl on 17 July 2026, and its filings since give North Las Vegas, Nevada, as the principal executive office. No operating, SEC-listed construction company is headquartered in Illinois. For national firms with Illinois offices, see the largest construction companies.
Hiring an Illinois contractor
- Ask which licenses apply to your job and where: IDPH for plumbing, IDFPR for roofing, the local municipality for general and electrical work.
- Verify each license on IDPH's plumbing license verification or IDFPR's license lookup, and with your city or village.
- For public or highway work, confirm the firm appears in IDOT's prequalified or subcontractor directory.
- Check local permits from recent jobs like yours, and get insurance certificates and lien waivers.
Prospecting Illinois contractors
| Segment | Size | Where the names are |
|---|---|---|
| Highway and heavy civil | 459 Illinois prequalified contractors, 681 Illinois subcontractors | IDOT directories |
| Plumbing contractors | Registered annually with IDPH | IDPH license verification |
| Roofers | Licensed by IDFPR | IDFPR license lookup |
| Mechanical and electrical trades | 7,103 establishments | Associations, local licenses and permits |
| Residential builders | 8,062 establishments | Home Builders and Remodelers Association of Illinois members, local permits |
At the 27,238 establishments with fewer than 20 employees, the owner decides. At the 286 with 100 or more, find equipment, safety, procurement and preconstruction leaders.
Illustrative example. The company and its assumptions are invented; the directory counts are from IDOT.
Prairie Traffic Rentals (prairietraffic.example) rents message boards, barricades and attenuator trucks for highway work zones. Its list starts with IDOT's 459 Illinois prequalified contractors and 681 Illinois subcontractors: 1,140 firms. If a third run work zones each season and it wins 15% of those at $40,000 a season, that's 57 customers and $2.28 million a year. Matching each firm to the lettings it just won is the slow research; Bebop researches each company on a list like this and drafts the first email.
Sources for names
| Source | What it gives you |
|---|---|
| IDOT prequalification and registration | Prequalification rules and the weekly contractor and subcontractor directories |
| IDPH plumbing | Plumbing license rules and license verification |
| IDFPR regulated professions | Roofing contractor licensing and the state license lookup |
| ABC Illinois | Merit shop contractors statewide |
| Home Builders and Remodelers Association of Illinois | Residential builders and remodelers |
| Illinois Chamber of Commerce | Statewide business chamber |
| Census Building Permits Survey | Housing units authorized by state, metro, county and city |
Next step: go deeper on the largest market with the Chicago construction companies report, or build a list with the construction companies industry guide.
Sources
- County Business Patterns 2023, US Census Bureau, accessed 30 October 2026
- Building Permits Survey, annual state data for 2024 and 2025, US Census Bureau, accessed 30 October 2026
- Prequalification and registration (contractor and subcontractor directories), Illinois Department of Transportation, directories compiled 26 October 2026, accessed 30 October 2026
- Plumbing, Illinois Department of Public Health, accessed 30 October 2026
- Licensed professions, Illinois Department of Financial and Professional Regulation, accessed 30 October 2026
- BOXABL Inc. (formerly FG Merger II Corp.) Form 10-K for 2025, US Securities and Exchange Commission (EDGAR), 31 March 2026
- BOXABL Inc. Form 8-K (completion of business combination), US Securities and Exchange Commission (EDGAR), 23 July 2026
Written by the Bebop team at Blackpearl Group. Published .
Questions people ask
How many construction companies are in Illinois?
The Census Bureau counted 29,457 construction establishments with paid employees in Illinois in 2023, employing 229,716 people. That's 3.62% of the US total and 5th among states. Cook County had 10,711 and DuPage County 3,051. The count is of locations rather than companies, and it excludes self-employed contractors with no employees.
Does Illinois require a general contractor license?
Not at the state level. Illinois licenses plumbers through the Department of Public Health, which also requires plumbing contractors to register annually, and licenses roofing contractors through the Department of Financial and Professional Regulation. General contractors aren't on the state's list of regulated professions, so licensing is local; the City of Chicago, for example, issues five classes of general contractor license.
How do I find IDOT prequalified contractors?
IDOT posts its prequalified contractor directory and its registered subcontractor directory as text files on its prequalification and registration page, updated every Monday. The October 26, 2026 lists had 580 prequalified contractors, 459 with Illinois addresses, and 821 registered subcontractors. Each entry gives the firm's address and phone, plus its work categories or codes.
How much do construction workers make in Illinois?
Construction establishments in Illinois paid an average of $90,240 per employee in 2023, according to Census County Business Patterns: $20.73 billion in payroll across 229,716 employees. That's fourth-highest among the states and DC, behind Alaska, Massachusetts and Minnesota, and well above the US average of $76,580. It's an average across all construction jobs.
Are there public construction companies headquartered in Illinois?
Not operating ones. The only Illinois-addressed construction filer on SEC EDGAR, BOXABL Inc. of Itasca, was a blank-check company called FG Merger II Corp. until it merged with Boxabl on 17 July 2026, and its filings since give North Las Vegas, Nevada, as the head office. Large Illinois contractors are private and don't publish revenue.