The Department of Buildings enforces the Chicago Building Code, which includes the Chicago Heat Ordinance. The Heat Ordinance mandates that during cold weather months landlords supply heat to rental units or to any unit where owners do not have individual control of the heat.
From September 15 through June 1, the temperature inside a rental residence is required to be at least 68 degrees from 8:30 AM to 10:30 PM, and at least 66 degrees from 10:30 PM to 8:30 AM.
Landlords face fines of up to $500 per day, per violation, for each day they do not supply adequate heat. The reason for lack of heat does not matter -- landlords must follow the law, and apartments must be heated.
If you are a renter and your landlord is not providing adequate heat or no heat at all, please contact 311 to file a complaint. The Department of Buildings will inspect your unit and we will take action against delinquent owners.
Municipal Code 13-196-410 Residential Buildings (which can be accessed online).