Illinois requires sellers to complete a detailed 23-item disclosure report plus a separate radon disclosure, and it licenses home inspectors through the Department of Financial and Professional Regulation. Chicago-area buyers face an extra layer: old brick construction, clay soil, brutal freeze-thaw cycles, and basement seepage. This guide covers the disclosure rules, inspector licensing, the regional hazards, and what inspections cost.

Illinois's disclosure report: 23 line items plus a separate radon form

Illinois's Residential Real Property Disclosure Act (765 ILCS 77/35) requires sellers to complete the Residential Real Property Disclosure Report and deliver it to the buyer before the contract is signed. The form covers 23 specific line items — flooding or leakage in the crawl space or basement, flood-plain status, defects in the foundation, roof, walls, floors, electrical, plumbing (including sump pumps), well and septic systems, HVAC, fireplace, radon, asbestos, lead paint and lead pipes, soil settlement, termites, underground fuel tanks, boundary disputes, legal violations, and whether the property was ever used as a methamphetamine lab.

The report's stated purpose is to give buyers information about material defects before contracting, and completing it creates legal obligations for the seller. It is not a warranty, and the parties can still contract for an "as is" sale — but the disclosure duty stands regardless.

Illinois also requires a separate radon disclosure under the Illinois Radon Awareness Act. The seller must give the buyer the Disclosure of Information on Radon Hazards form and the state pamphlet "Radon Testing Guidelines for Real Estate Transactions," and must share any radon test results in the seller's possession showing elevated levels. The disclosure must be delivered before the buyer becomes obligated under the contract. The seller is not required to test or mitigate — only to disclose — but in practice, elevated results become a negotiation item.

Inspectors are licensed by IDFPR — verify the license

Illinois licenses home inspectors under the Home Inspector License Act (225 ILCS 441), administered by the Illinois Department of Financial and Professional Regulation (IDFPR). Performing inspections for compensation without a license is illegal.

  • At least 18 years old with a high school diploma or equivalent.
  • 60 hours of approved pre-license education.
  • Five supervised field inspection events plus a field exam (scored at 70% or better), completed under a licensed Illinois inspector.
  • Passing the state home-inspector examination, which includes the National Home Inspector Examination plus Illinois-specific statute and regulation content.
  • A $250 application fee and general liability insurance of at least $100,000.
  • Renewal every two years (November 30 of even-numbered years), with 12 hours of continuing education per cycle.

Because licensure is mandatory, verifying an inspector's license through IDFPR is quick and non-negotiable — do it before you book.

Hazard 1: radon in northern Illinois

The Illinois Emergency Management Agency recommends that all homebuyers have an indoor radon test performed before purchase or occupancy — and northern Illinois counties, including much of the Chicago metro area, have some of the state's highest radon potential. The geology that makes for good farmland also produces radon, and it concentrates in basements — which nearly every Chicago-area home has.

A radon test during the inspection period typically costs $150 to $250 as an add-on. If levels exceed the EPA action level of 4 pCi/L, mitigation with a sub-slab depressurization system typically runs in the low four figures and is routinely negotiated with the seller. Because Illinois requires the seller to disclose known elevated results, compare the radon disclosure form against your own test — and test regardless of what the form says, since levels vary house to house.

Hazard 2: freeze damage, ice dams, and frost

Chicago winters are an inspection category of their own. The freeze-thaw cycle punishes roofs, masonry, and plumbing:

  • Ice dams: heat escaping into a poorly insulated or ventilated attic melts roof snow, which refreezes at the eaves and forces water back under the shingles. Your inspector should evaluate attic insulation depth and ventilation as a system, not just glance at the shingles.
  • Frozen pipes: supply lines in unconditioned crawl spaces, exterior walls, and additions are vulnerable. Ask about the pipe routing and whether the home has a history of freeze events.
  • Frost heave and masonry damage: water entering small cracks in foundations, chimneys, tuckpointing, and flatwork expands when it freezes. Spalling brick, deteriorated mortar, and displaced chimney crowns are common findings.
  • Furnace and boiler age: heating systems work hard in Illinois. Confirm the age, service history, and remaining life of the furnace or boiler — a mid-winter failure is the most expensive surprise in this market.

Hazard 3: Chicago's brick, tuckpointing, and basement seepage

Much of Chicago's housing stock is brick construction — two-flats, greystones, bungalows, and courtyard buildings — and brick of that era needs periodic tuckpointing (mortar joint repair). Deteriorated mortar lets water into the wall assembly, and neglected parapet walls on flat-roofed buildings are a classic Chicago leak source. Your inspector should check mortar condition, parapet coping and flashing, and lintels over windows and doors.

Below grade, basement seepage is the Chicago area's most common expensive finding. Clay soils drain slowly, the water table can run high near the lake and rivers, and older homes often lack modern exterior waterproofing. Look for efflorescence, staining, and musty odor; check sump pumps, battery backups, and overhead-sewer or backflow-prevention setups (Chicago's combined sewers can back up in heavy storms — ask whether the home has overhead sewers or a check valve). A finished basement that has never taken water is worth confirming, not assuming.

Other Chicago-specific checks: galvanized or lead water service lines (the city has a large inventory of lead service lines — know what the home has), flat-roof condition and drainage on two-flats, and porch and deck structural condition.

Hazard 4: clay soil, drainage, and downspout discharge

The Chicago region sits on heavy clay soils that expand when wet, shrink when dry, and drain poorly. The practical consequence is foundation stress and water management problems. Grading should slope away from the foundation, and downspouts should discharge well away from the house — into clay, water dumped at the foundation line does not percolate; it builds hydrostatic pressure against basement walls.

Have the inspector look for stepped cracking in block or brick foundations, horizontal cracking or bowing (which warrants a structural engineer's opinion), and window wells that collect water.

What an Illinois home inspection typically costs

Statewide, a standard single-family inspection in Illinois typically runs $325 to $425, with the Chicago market higher: expect $350 to $550 for a typical single-family home up to about 2,000 square feet, and $475 to $725+ for larger homes. Condos and townhomes generally run $300 to $450. Two- to four-unit buildings are priced per building and run significantly higher, often $695 to $1,095 for the whole building.

Common add-ons in Illinois:

  • Radon testing: $150 to $250 — budget this as standard practice, not an optional extra, in northern Illinois.
  • Sewer scope: $150 to $250 — worthwhile on older homes with clay tile laterals and mature parkway trees.
  • Termite/WDI inspection: $75 to $150 — required by VA and many other loan programs.
  • Mold testing: $250 and up — only if the inspection reveals moisture or visible growth.

Get a written quote specifying square footage, what's included, and turnaround time. In the Chicago market, inspection contingencies often run on tight attorney-review timelines, so confirm the inspector can deliver the report fast enough for your deadlines.

What this guide does not cover — and when to call a specialist

A general home inspection is a visual, non-invasive survey of accessible systems at a point in time — not a code inspection, an appraisal, or a warranty. In Illinois, bring in a licensed plumber for sewer and water-service questions, a structural engineer for foundation movement, a qualified radon mitigator for elevated test results, and a chimney professional for flue concerns. This guide is general information, not legal advice: if the disclosure report looks incomplete or contradicts your inspector's findings, consult an Illinois real estate attorney before your contract deadlines pass.

Frequently asked questions

Is a home inspection required to buy a house in Illinois?

No. Illinois law does not require buyers to get inspections. But the standard contract's inspection contingency — negotiated through attorney review in the Chicago area — is the main mechanism for discovering defects the seller's disclosure missed, and waiving it removes your best protection.

Should I test for radon in the Chicago area?

Yes. The state emergency management agency recommends every buyer test before purchase or occupancy, northern Illinois has elevated radon potential, and nearly every Chicago-area home has a basement where radon concentrates. A $150–$250 test during the inspection window is inexpensive insurance.

How do I verify an Illinois home inspector's license?

Look up the inspector through the Illinois Department of Financial and Professional Regulation's license lookup before you hire. Anyone performing home inspections for compensation in Illinois must hold a current IDFPR license — unlicensed inspection activity is illegal in the state.

What should I focus on in a Chicago brick two-flat or bungalow?

Mortar and tuckpointing condition, parapet walls and coping on flat roofs, basement seepage and sump systems, the water service line material, porch and stair structural condition, and the age of the heating system. These are the items that most often surprise buyers of vintage Chicago housing.

The disclosure says "as is" — does the seller still have to disclose defects?

Yes. Illinois allows parties to contract for an "as is" sale, but the Residential Real Property Disclosure Act's disclosure duty still applies. "As is" describes the seller's repair obligations, not their duty to tell you about known material defects.