Certificate of Occupancy (new building, change of occupancy, or Group A assembly build-out): Chicago restaurant guide
Chicago Department of Buildings
What it is
DOB's confirmation that a finished building or space may be occupied for its use. It is mandatory for new construction, a change of occupancy (for example a storefront or warehouse becoming a restaurant), and construction or substantial rehabilitation of any assembly (Group A) space regardless of size; restaurants with an occupant load of 50 or more are Group A-2.
When a restaurant needs it
New buildings; any change of occupancy to restaurant use; construction or substantial rehab of a dining space with 50+ occupants; or more than 10,000 sq ft of non-residential work. Smaller projects may request one voluntarily.
How to apply
Comes through the building permit: the permit holder schedules and passes every required inspection as work progresses, then submits the online Certificate of Occupancy Application when work is nearing completion. DOB schedules the final inspections (and gives you the Fire Prevention Bureau contact if needed), you pay any outstanding inspection fees, and you pick up the hard-copy certificate.
Documents you’ll need
- Issued building permit
- Passed inspections for every trade as work progressed
- Online Certificate of Occupancy Application (technical and contact information)
- Payment of any outstanding inspection fees
Good to know
Occupying a space that needs a certificate without one (or a partial/temporary certificate) is illegal. Many older Chicago storefronts have no certificate on file; a pure takeover with no construction doesn't create a new one, but any change of occupancy does.
Official source
DOB — Certificates of Occupancy · DOB — occupancy classification (Group A at 50+ occupants)
Answer a few questions about your space and get every permit in order, with a timeline, a cost range, walkthroughs, and every application filled in for you to sign with Open.
Last reviewed 2026-10-06. Guidance only, not legal advice.