How to check a Chicago home for unpermitted work
Chicago publishes every building permit it issues and every violation its inspectors write, and both are free to search by address. Unpermitted work shows up as a mismatch: a finished basement or a rear addition that no permit in the record ever covers.
The short version: pull the property's permit history and its violation history, then compare both against what you can see in the listing photos and at the viewing. You are looking for three things — work with no matching permit, permits opened and never closed out, and violations that say the work was done without one. The city's violation file records 83,487 citations whose text mentions work done without a permit.
Permit History & Discrepancy report Search city building records free
Doing it yourself, free
- Search the address in the city's Building Records search. It returns permits, inspections, violations and complaints for the property. You will need to accept the city's terms; the search itself is free.
- List every permit and its type. Most residential work falls under a small number of types — the mix in the current file is in the table below — and a renovation of any size should have one.
- Look for the gaps. A third bathroom, a finished basement, a deck, a rear addition, a new electrical panel: each should have a permit. Work you can see with no permit behind it is the finding.
- Check whether permits were closed out. A permit issued is not work inspected. A permit with no final inspection recorded is a loose end a buyer inherits.
- Read the violations. Search the description and ordinance text for permit language — the city writes citations such as PLANS & PERMITS REQ - CONTRCTR when work was done without one.
- Ask the seller directly, in writing, about anything you found. An owner who pulled a permit will usually say so; the answer, and its absence, both matter.
Chicago permits by type, issued since 2021
| Permit type | Permits | Share |
|---|---|---|
| PERMIT – EXPRESS PERMIT PROGRAM | 94,819 | 47.2% |
| PERMIT - RENOVATION/ALTERATION | 37,220 | 18.5% |
| PERMIT - EASY PERMIT PROCESS | 33,493 | 16.7% |
| PERMIT - SIGNS | 13,802 | 6.9% |
| PERMIT - NEW CONSTRUCTION | 8,182 | 4.1% |
The five most common of 9 permit types, out of 201,012 permits issued since 1 January 2021 in the city's published file. Violations: 83,487 of 2,030,308 citations on record (4.1%), covering 01 Jan 2006 to 25 Sep 2026, mention work done without a permit in their description or ordinance text.
What the permit record can't tell you
- No permit is not proof of unpermitted work. Some work genuinely needs no permit, and records before the city's files begin are simply absent. A gap is a question to ask, not a finding.
- A permit is not an inspection. Issued, and completed to code, are different facts; look for the final inspection, not the permit.
- Addresses are messy. Corner buildings, re-numbered lots and units filed under the building address all break a naive address search. A search that returns nothing may be a search that matched nothing.
- A violation is a city finding, not a court judgment, and the file records the citation and its status, not how any dispute ended.
- It is Chicago only. Suburban Cook County municipalities issue their own permits and none of them are in this file.
Our Permit History & Discrepancy report does the address matching and the permit-to-listing comparison for one property and states what it could not match, rather than reporting silence as a clean record.
Every figure on this page, and where it came from
Every number above is recomputed from the loaded records each time this page is built. Last rebuilt 2026-09-28.
City of Chicago open data, loaded in full through the city's Socrata API and reconciled against its own row count.
Questions people ask
How do I find out if work on a Chicago house was permitted?
Search the address in the City of Chicago Building Records search, which is free, and compare the permits listed against the work you can see. The underlying data is also published as open data: building permits and building violations.
Does unpermitted work show up as a violation?
Sometimes. 83,487 of the 2,030,308 Chicago building violations on record mention work done without a permit — but a violation only exists if an inspector came. Most unpermitted work is found by comparing permits against what is actually there, not by finding a citation.
Who is responsible for unpermitted work after a sale?
In practice the current owner, who inherits the obligation to bring the property into compliance and any open violation on its record. That is why the check belongs before the contract, not after.
Is the city's building records search free?
Yes. The Building Records search and both open-data files cost nothing. Where the government gives the record away, we point you at it — our free lookup guides list the others.