Illinois Seller Disclosure Requirements: What Home Sellers Must Reveal

What Illinois Law Requires Sellers to Disclose

Selling a home in Illinois means filling out one of the more detailed disclosure forms in the country. The Illinois Residential Real Property Disclosure Act (765 ILCS 77) requires sellers to report known material defects and conditions that could affect a buyer’s decision. Getting this wrong — or skipping disclosures entirely — can lead to lawsuits, rescinded sales, and significant financial liability. Here’s exactly what Illinois sellers must reveal, what they can leave out, and what happens when they don’t comply.

The Illinois Residential Real Property Disclosure Act

Illinois passed its disclosure law in 1998, and it has been updated several times since. The statute requires sellers of residential property (1-4 units) to complete a written disclosure report and deliver it to the buyer before or at the time of the purchase contract. The form covers 23 categories of potential issues, from structural problems to environmental hazards.

The key legal standard is “known” defects. Illinois uses a “seller knowledge” standard rather than requiring independent inspections. Sellers must disclose what they actually know about the property — they aren’t required to hire inspectors or test for problems they have no reason to suspect. However, the law specifically states that a seller cannot avoid disclosure by simply choosing not to investigate obvious issues. Courts have consistently ruled that willful ignorance doesn’t shield sellers from liability.

The disclosure form uses a checkbox format with three options for each item: the condition exists, it does not exist, or the seller has no knowledge. That third option — “no knowledge” — carries legal weight. If a buyer later proves the seller did have knowledge of a problem they claimed ignorance about, the seller faces liability for fraudulent misrepresentation.

What Sellers Must Disclose: Category by Category

The Illinois disclosure form covers a wide range of property conditions. Here are the major categories and what falls under each:

Structural and Mechanical Systems

Sellers must disclose known problems with the foundation, basement, walls, roof, and load-bearing elements. This includes past or present water infiltration in the basement, cracks in the foundation, roof leaks, and any structural repairs that have been made. The form also asks about the condition of the electrical system, plumbing, HVAC, water heater, and sump pump.

If a seller finished a basement and knows the space has a history of water problems, they must disclose that history even if the current waterproofing system appears to be working. Past conditions matter as much as present ones.

Environmental Hazards

Illinois requires disclosure of known environmental hazards including:

• Radon: Any known radon test results must be disclosed, regardless of the levels found. Illinois has significant radon exposure — the EPA estimates that about 50% of Illinois homes have radon levels above the recommended action level of 4 pCi/L.
• Lead paint: Federal law (separate from the state disclosure) requires lead paint disclosure for all pre-1978 homes. Sellers must provide any known information about lead-based paint and give buyers a 10-day testing period.
• Asbestos: Known presence of asbestos in insulation, floor tiles, siding, or other materials must be disclosed.
• Underground storage tanks: Any known current or former underground fuel tanks on the property.
• Mold: Known mold problems, including past remediation efforts.

Water and Flooding

Sellers must disclose whether the property is in a FEMA-designated flood zone, whether they’ve ever filed a flood insurance claim, and whether the property has experienced flooding or water damage. This includes water in the basement, even if it only happens during heavy storms. Any drainage problems, standing water issues, or sewer backup history must also be reported.

Boundaries and Easements

Known boundary disputes, encroachments (fences, structures, or landscaping that cross property lines), and easements must be disclosed. This includes utility easements, shared driveways, and any agreements with neighbors about property use. If the seller is aware that a survey would reveal discrepancies with assumed property lines, that’s disclosable.

HOA and Shared Obligations

If the property is part of a homeowners association, the seller must disclose the existence of the HOA, monthly or annual fees, any special assessments that have been levied or are pending, and any known violations of HOA rules. In condominiums, the seller must also provide the buyer with certain governing documents under the Illinois Condominium Property Act.

Code Violations and Legal Issues

Any known building code violations — current or past — must be disclosed, along with whether they were resolved. This includes unpermitted work. If the seller added a bathroom, finished a basement, or built a deck without pulling proper permits, they must disclose that fact. Zoning violations, pending litigation related to the property, and any government notices (such as condemnation proceedings) also require disclosure.

Required Disclosures: Summary Table

What Sellers Do NOT Have to Disclose

Illinois law carves out several categories that sellers are not required to reveal, even if the buyer asks directly:

Deaths on the property. Illinois specifically exempts sellers from disclosing that a death occurred on the property, including deaths by murder, suicide, or natural causes. A 1990s amendment to state law removed any obligation to disclose this information, and it cannot be treated as a material defect.

Sex offender registry. Sellers have no obligation to tell buyers that a registered sex offender lives nearby. Buyers can check the Illinois State Police Sex Offender Registry independently.

Felony convictions of occupants. No duty to disclose the criminal history of current or former occupants.

HIV/AIDS status. A seller or occupant’s health status, including HIV/AIDS diagnosis, is explicitly protected from disclosure requirements under both state and federal fair housing law.

Buyers who care about these issues need to do their own research. Real estate agents are similarly restricted — they cannot volunteer this information, and in most cases, they cannot answer direct questions about these topics.

Who Is Exempt from the Disclosure Act

Not all residential sales in Illinois require the standard disclosure form. Exemptions include:

• Foreclosure sales: Lenders selling foreclosed properties are exempt because they typically have no firsthand knowledge of the property’s condition.
• Estate sales: Sales by executors, administrators, or trustees of a deceased owner’s estate are exempt, again because the seller likely lacks personal knowledge.
• New construction: Builders selling newly constructed homes are exempt from the residential disclosure act, though they are subject to implied warranty of habitability and must comply with building codes.
• Court-ordered sales: Sheriff’s sales, partition sales, and other court-ordered transfers are exempt.
• Transfers between co-owners: Sales between spouses, family members, or co-owners typically don’t require the standard disclosure.
• Sales “as-is” with disclosure waiver: Even in as-is sales, sellers must still complete the disclosure form unless the transaction falls into one of the above exempted categories. An as-is clause shifts repair responsibility but does not eliminate the disclosure requirement.

Buyers purchasing exempt properties — particularly foreclosures and estate sales — should budget for thorough independent inspections since they won’t have the benefit of seller disclosures. Factor these inspection costs into your closing cost estimates.

Consequences of Non-Disclosure

Failing to disclose known defects in Illinois can result in serious legal and financial consequences for sellers:

Rescission of the sale. If a buyer discovers undisclosed material defects before closing, they can void the contract entirely. After closing, rescission becomes harder but is still possible in cases of fraud.

Damages. Buyers who discover undisclosed defects after closing can sue for the cost of repairs, diminution in property value, and in some cases, consequential damages like temporary housing costs during repairs. Courts may also award attorney’s fees.

Fraud claims. If a seller actively concealed a defect — for example, painting over water stains or covering foundation cracks with drywall — the buyer can pursue fraud claims, which carry higher potential damages and may not be limited by the purchase price.

Real estate agent liability. Agents who know about undisclosed defects and fail to ensure proper disclosure can also face liability, plus disciplinary action from the Illinois Department of Financial and Professional Regulation.

The statute of limitations for disclosure claims in Illinois is generally one year from the date the buyer discovers (or should have discovered) the defect, but fraud claims can extend that timeline. Sellers should keep copies of their completed disclosure forms indefinitely as proof of what they disclosed.

Common Disclosure Disputes in Illinois

Certain types of undisclosed defects generate the most litigation in Illinois. Understanding these common disputes helps both buyers and sellers know where the stakes are highest.

Water and moisture problems. Basement water infiltration is the single most litigated disclosure issue in Illinois real estate. Sellers who paint basement walls, install new carpet over water-stained concrete, or add a sump pump without disclosing the underlying water problem face strong liability. Courts have found sellers liable even when the water issue was intermittent — a basement that floods only during heavy spring rains still requires disclosure. If you’ve ever run a dehumidifier in your basement regularly, dealt with musty odors, or found damp spots after storms, these conditions belong on the disclosure form.

Foundation and structural issues. Cracks in foundation walls, bowing basement walls, and uneven floors are common in older Illinois homes, particularly in areas with expansive clay soils (common in central and southern Illinois). Sellers who patch cosmetic cracks without disclosing the underlying structural concern create liability. Foundation repair receipts, engineering reports, or communications with contractors about structural issues should all be disclosed.

Sewer line defects. Many older Illinois communities have aging sewer infrastructure. Collapsed or root-damaged sewer laterals (the pipe connecting your home to the municipal sewer) are expensive to repair ($5,000-$15,000+) and are a frequent source of post-sale disputes. If you’ve had sewer backups, slow drains throughout the house, or had the sewer line scoped or repaired, disclose it. Buyers should consider a sewer scope inspection ($150-$300) before closing, especially on homes built before 1970.

Pest damage. Termite damage, carpenter ant infestations, and rodent problems must be disclosed if known. Illinois has active termite populations, particularly in the southern half of the state. Past termite treatments and any resulting structural damage are material facts. A clear pest inspection doesn’t erase the obligation to disclose previous infestations — if you had termites treated five years ago, that’s still disclosable even if a current inspection finds no activity.

Unpermitted work. Finished basements, added bathrooms, converted garages, and enclosed porches done without permits create liability for sellers. The property tax implications of unpermitted additions add another layer of risk — assessors can retroactively increase assessments when unpermitted improvements are discovered, and the new owner gets stuck with the higher tax bill.

Practical Advice for Buyers and Sellers

For buyers: Never rely solely on the seller’s disclosure form. Hire a qualified home inspector, and consider specialized inspections for older homes — radon testing, sewer line scoping, and lead paint testing for pre-1978 properties. The disclosure form tells you what the seller knows (or admits to knowing), but it doesn’t replace professional evaluation. Understanding your total purchase costs means accounting for potential issues the disclosure may not cover.

For sellers: Disclose everything you know, even if it seems minor. The cost of a reduced offer because you disclosed a past basement leak is almost always less than the cost of a lawsuit after closing. If you’re unsure whether something requires disclosure, err on the side of including it. Your real estate attorney can help you complete the form accurately. When preparing to list your home, completing the disclosure form thoroughly protects you legally. A good inspection matters — read our guide on how to choose a home inspector in Illinois.

Frequently Asked Questions

Does selling a home “as-is” mean I don’t have to complete the disclosure form?

No. In Illinois, selling as-is does not exempt you from the disclosure requirement unless the sale falls into a specific statutory exemption (foreclosure, estate sale, court order, etc.). An as-is clause means the buyer accepts the property’s current condition and the seller won’t make repairs — but the seller must still disclose all known material defects on the standard form. Failing to disclose a known defect in an as-is sale creates the same legal liability as in a standard sale.

What if I genuinely don’t know about a defect?

If you truly have no knowledge of a defect, you can mark “no knowledge” on the disclosure form, and you won’t be liable if the defect is later discovered. The key word is “genuinely.” Courts look at whether a reasonable person in your position would have been aware of the problem. If your basement floods every spring and you mark “no knowledge” of water problems, a court is unlikely to accept that claim. But if a hidden pipe is corroding inside a wall with no visible signs, you wouldn’t be expected to know about it.

Do I have to disclose repairs and renovations I’ve made?

You must disclose known defects and material conditions — and past repairs can fall into that category. If you repaired a structural issue, the existence of the original problem and the repair itself is material information. You should also disclose whether permits were pulled for renovation work. Unpermitted additions, electrical work, or plumbing modifications are specifically called out on the Illinois disclosure form. Check your local building department records if you’re unsure about permit status for work done during your ownership.

Can a buyer sue me years after the sale for an undisclosed defect?

Illinois has a one-year statute of limitations for residential disclosure claims, starting from when the buyer discovers (or reasonably should have discovered) the defect. However, fraud claims — where the seller intentionally concealed or lied about a defect — have a longer limitations period of up to five years from discovery. This is why active concealment (hiding problems) carries much more legal risk than simply forgetting to mention something. Keep your completed disclosure form and any supporting documentation permanently.

My real estate agent says I should disclose less to avoid scaring buyers. Is that good advice?

No, and an agent who advises under-disclosure is giving you dangerous counsel. Illinois courts have consistently held sellers liable for defects they knew about but failed to disclose, and the legal costs of a non-disclosure lawsuit far exceed any reduction in sale price from honest disclosure. A good agent will help you present disclosures in factual, non-alarming language while ensuring completeness. If your agent pressures you to omit known defects, consider finding a different agent — and consult a real estate attorney before signing the disclosure form. Understanding your financial obligations as a seller includes protecting yourself from post-sale liability.