About the data
AlderWorks builds only on free, official public records whose terms allow this use, and every page names its sources and the date it read them.
Rootstone
Collected twice a day from the city and county portals. We keep the fields we use and a link to each original record.
We sort records into trades, group everything at one address into a single lead, add ZIP codes and community areas, and match addresses to Cook County parcels to find owner mailing addresses. A match we are unsure of is labelled as a guess, never presented as fact.
- City of Chicago, Building Violations
- City of Chicago, Building Permits
- City of Chicago, Food Inspections
- City of Chicago, Ordinance Violations (Administrative Hearings)
- City of Chicago, Building Code Scofflaw List
- Cook County Assessor’s Office, Assessor – Parcel Addresses
Illinois Property Report
Read live from the official portals when you open a report, and kept in Cloudflare's cache for up to a day. Nothing is copied into our database.
We find the parcel at your address, turn codes into words, group violations into open and past, count each hearing's fine once, and calculate the market value the assessment implies. Owner and buyer names appear only for signed-in accounts.
- City of Chicago, Building Violations
- City of Chicago, Building Permits
- City of Chicago, Ordinance Violations (Administrative Hearings)
- City of Chicago, Building Code Scofflaw List
- Cook County Assessor’s Office, Assessor – Parcel Addresses
- City of Chicago, 311 Service Requests
- City of Chicago, Ward Offices
- Cook County Assessor’s Office, Assessor – Parcel Universe, Characteristics, Assessed Values and Sales
Bid Intelligence
Read live from the official portals when you open a page, and kept in Cloudflare's cache for up to a day. Nothing is copied into our database.
We group contract revisions and amendments into one row per contract, sort bidders by price, and calculate low, median and spread. City grants to delegate agencies are left out.
- City of Chicago, Contracts
- U.S. Department of the Treasury, USAspending.gov award data (federal contracts in Cook County)
- U.S. General Services Administration, SAM.gov contract opportunities (open federal solicitations in Illinois)
- Cook County, Procurement – Awarded Contracts, Bid Tabulations, Intent to Award, Buying Plan
Politria
Politria has its own sources (the Illinois General Assembly and others), listed on its own site.
Caveats
Building violation records show what the city cited and when; they do not necessarily reflect a building's current condition, and some cases end with the owner found not liable. Do not rely on them for real-estate transactions without checking with the city.
The Assessor updates owner names only from time to time, and lists some parcels under a different address than the city uses, so an address search can miss a large building.
Owner and mailing addresses come from the Cook County Assessor’s Office open data. Cook County does not endorse AlderWorks or its products.
This site provides applications using data that has been modified for use from its original source, www.cityofchicago.org, the official website of the City of Chicago. The City of Chicago makes no claims as to the content, accuracy, timeliness, or completeness of any of the data provided at this site. The data provided at this site is subject to change at any time. It is understood that the data provided at this site is being used at one’s own risk.