IL State Guide
Home improvement costs in Illinois.
Locally calibrated cost data for fifty trades, plus the permit rules, code gotchas, and building conditions that actually matter when you plan a project in Illinois.
Updated June 2026
Cost calibration
Illinois costs are right at the national average.
Illinois sits at the national average for overall cost, but Cook County (Chicago and inner suburbs) runs 15-25% above the rest of the state because of strong trade unions and a Chicago-only electrical code that differs from the National Electrical Code. Downstate Illinois projects often come in significantly cheaper than Chicago equivalents. Older Chicago housing stock (lots of pre-1950 builds, brick three-flats, balloon-frame walkups) adds renovation complexity that downstate single-family ranches do not have.
BEA RPP
1×
Regional Price Parity
BLS Labor Index
1.04×
Trades-labor metro adjustment
Permits
Permits in Illinois.
Illinois adopted the 2018 IRC statewide but allows home rule municipalities to amend. Chicago operates under the Chicago Construction Codes, which include the famous Chicago Electrical Code (different from NEC). Permits are issued by the municipality or county. Chicago Department of Buildings handles all city work; suburbs each have their own departments. Homeowner permits are allowed for owner-occupied single-family residences but Chicago requires licensed contractors for most trades.
Where to file: Chicago: Department of Buildings online portal. Suburbs: village or municipality building department. Downstate: city or county building office. Chicago plan review takes 4-8 weeks for larger projects.
| Trade | Required when | Citation | Typical fee | Homeowner DIY? |
|---|---|---|---|---|
| Plumbing | In-wall work, fixture replacement, water heater, gas | Illinois Plumbing Code (77 Ill Adm Code 890) | $100-$400 | NoIllinois requires licensed plumber statewide; one of the strictest licensing regimes |
| Electrical | New circuits, panel work, service upgrades, EV charger | Chicago Electrical Code (city); NEC (rest of state) | $100-$400 | ConditionalChicago requires licensed electrician; suburbs and downstate often allow homeowner DIY |
| Mechanical (HVAC) | Furnace/AC change-out, ductwork, refrigerant work | Illinois Energy Conservation Code; IMC | $100-$300 | NoRefrigerant + gas require licensed contractor |
| Building (structural) | Additions, structural modifications, decks, finished basements | IRC as adopted; Chicago Construction Codes | $150-$1,500 | YesEngineered drawings often required; finished basements need egress windows |
| Roofing | Re-roofs, structural deck repair | Local jurisdiction | $75-$300 | YesIce-and-water shield required; consider hail-resistant shingles |
| Demolition (Chicago) | Any structural demo opening walls | Chicago Building Code | $100-$300 | YesPre-1980 buildings need asbestos survey before demo permit |
Code highlights
What catches DIYers in Illinois.
Five code rules that show up on inspector reports more than any others. Catch them before demo day.
Chicago Electrical Code (not the NEC)
Chicago has its own electrical code dating back to 1968. Conduit is required for all wiring (no Romex); aluminum is restricted; specific receptacle types apply. Non-Chicago electricians often miss these rules during alterations. If you bought materials at a suburban Home Depot, half of it might not pass inspection in the city.
Illinois licensed plumber requirement
Illinois has one of the strictest plumbing licensing regimes in the country (77 Ill Adm Code 890). Even homeowner-pulled permits require licensed plumber work in most jurisdictions. DIY plumbing on a covered project will fail inspection and cannot be easily fixed after the fact.
Basement egress window requirements
Any habitable room in a basement must have an egress window (5.7 sq ft net clear opening, 24" min height, 20" min width, well drainage if below grade). Finishing a basement without egress windows is a common DIY mistake that fails final and requires expensive excavation to fix.
Tuckpointing and brick masonry inspection
Chicago and inner suburbs have huge brick housing stock. Mortar joints fail every 50-80 years and need tuckpointing ($8-$20/sq ft of wall). Many homeowners discover this during exterior projects. Budget for a brick inspection before any major exterior or window replacement.
Radon mitigation in basements
Northern and central Illinois have Zone 1 radon (highest). Real estate transactions routinely require radon testing; remediation runs $1,000-$2,500. Finishing a basement is a good time to add a passive radon mitigation system ($300-$600 extra during construction).
Local building conditions
What changes in Illinois.
Illinois home improvement is shaped by an old Chicago housing stock, harsh winters, the most unique electrical code in America, and a strong unionized trade culture in the metro. Plan for Chicago-specific rules separately from the rest of the state.
Frost line depth
42 inches (most of state), 48 inches (far northern IL)
Deck footings, foundation piers, and frost-protected slabs need to extend below this depth. Frost-heave damage to walkways and porches is common in pre-1980 homes during renovation.
Snow load
20-30 psf (most of state), 30-40 psf (far north)
Standard residential framing handles most Illinois snow loads. Garage additions and porches need verified load calculations during permit review.
Housing age (Chicago metro)
~40% of Cook County housing pre-1950
Lead paint, asbestos, knob-and-tube wiring, galvanized supply, undersized panels show up regularly. Pre-1978 EPA RRP rules apply on all painting and renovation. Budget 15-20% contingency.
Radon (Zone 1, highest risk)
Most of northern + central IL is in EPA radon Zone 1
Radon testing during real estate sales is routine. Passive mitigation during construction is cheap; retrofit is $1K-$2.5K. Add a radon stub during any basement work.
Tornado exposure
Central and southern IL are in active tornado belt
Storm shelters are common in central IL but not required. Roofing in tornado-prone areas should be 6-nail fastening minimum, even though code only requires 4-nail in most jurisdictions.
Trade union strength (Cook County)
Strong electrical, plumbing, sheet metal unions
Chicago labor rates are 25-40% above the national average. Suburbs are softer but still elevated. Downstate is significantly cheaper.
Cost data
Top home improvement projects in Illinois.
Hire-it-out cost ranges for the most-searched projects, calibrated to Illinois labor + materials.
| Project | Cost range | Difficulty |
|---|---|---|
| AC Replacement → | $4,600–$9,200 | Hard |
| Attic Insulation → | $1,500–$3,600 | Moderate |
| Backsplash Tile → | $800–$2,600 | Easy |
| Baseboard & Trim Installation → | $700–$3,100 | Easy |
| Basement Finishing → | $15,300–$51,000 | Hard |
| Bathroom Remodel → | $6,600–$18,400 | Moderate |
| Bathroom Vanity Installation → | $400–$1,500 | Moderate |
| Cabinet Refacing → | $4,100–$12,200 | Moderate |
| Carpet Installation → | $700–$2,600 | Moderate |
| Ceiling Fan Installation → | $200–$600 | Moderate |
Need a specific project priced for your zip? Open the calculator →
Local contractors
Illinois Local Pros.
Illinois is on the Local Pros roadmap. We are sourcing from r/AskChicago and r/HomeImprovement Illinois threads, NextDoor neighborhood recommendations, and Illinois Department of Financial and Professional Regulation licensing records. Chicago contractors filtered separately because of city-specific code expertise.
See Illinois Local Pros →Plan your Illinois project