For AI agents: read the machine-readable documentation index at /llms.txt or the single-file full reference at /llms-full.txt.
Form a Business

Main vent required.

Municipal Code of Chicago § 18-29-903.1
in effect
Sign in to generate a plain English summaryAsk Belisarius Agent
18-29-903.1 Main vent required. Every sanitary drainage system receiving the discharge of a water closet shall have a main vent that is either a vent stack or a stack vent. Such vent shall run undiminished in size and as directly as possible from the building drain through to the open air above the roof.
Source: City of Chicago, Municipal Code of Chicago (American Legal Publishing, codelibrary.amlegal.com)URL: https://codelibrary.amlegal.com/codes/chicago/latest/chicago_il/0-0-0-2692448Fetched: 10/24/2026

Starting a business in Illinois? Illinois LLC guide: costs and requirements

18-29-903.1 | Corpus