Illinois building code

Codes in force in Illinois

Each code family with the edition and the date it took effect, as the adopting agency or statute states them.

Scope, amendments and transition rules

International Residential Code (IRC)

Scope

Statewide minimum; local governments may go further⁶

Applies to

New residential construction only⁶

Local amendments allowed?

Yes¹

International Building Code (IBC)

Scope

Statewide minimum; local governments may go further⁶

Local amendments allowed?

Yes¹

International Existing Building Code (IEBC)

Scope

Statewide minimum; local governments may go further¹

Applies to

Not existing single-family repairs⁶

Energy code, residential

Scope

Statewide; applies everywhere⁶

Applies to

All buildings; enforcement only where locally adopted⁶

Local amendments allowed?

Yes⁶

Energy code, commercial

Scope

Statewide; applies everywhere⁶

Applies to

All buildings; enforcement only where locally adopted⁶

Local amendments allowed?

Yes⁶

State code: Illinois Stretch Energy Code

Scope

Adopted locally⁶

State code: Illinois Plumbing Code

Scope

Statewide; applies everywhere⁸

State code: NFPA 101, Life Safety Code

Scope

Statewide minimum; local governments may go further⁹

Local amendments allowed?

Yes⁹

How Illinois adopts building codes

20 ILCS 3105/10.09-1 and 10.18; 815 ILCS 670/15; 20 ILCS 3125/15 and 55; P.A. 103-0510

• Statewide baseline effective January 1, 2025. The State of Illinois recently passed legislation ( Public Act 103-0510 ) changing the Capital Development Board Act to require statewide building codes effective 1/1/2025.¹
• Local code official answers code questions. The best and most accurate answers to building code questions must be answered by your city, village, or county code official.¹
• State has no repair code for existing single-family homes. The State has not adopted a building code for repairs to existing single family residences.⁶
• Local codes must report to CDB, 30 days before effect. 20 ILCS 3105/10.18 requires that all municipalities or counties adopting a new building code or amending an existing building code must provide an identification of the code by title and edition including local amendments to CDB at least 30 days before the effective date of the building code.¹
• Local code directory exists. Local codes can be looked up using our online portal at Illinois Code Directory .⁶
• Mechanical and fuel gas codes not named by CDB. The following paragraphs summarize major construction codes only.¹

Applies to

Local codes and amendments, subject to the baseline¹

Can local rules be stricter?

Yes¹

What local governments may change

225 ILCS 320/42 (as quoted in an IDPH memo dated April 9, 2013)

• Plumbing licensing and code reserved to State. …the power to regulate the licensing of plumbers, to promulgate a minimum plumbing code of standards, and to regulate the registration of irrigation contractors and plumbing contractors shall, except as may otherwise be provided within and pursuant to the provisions of Section 16 and Section 16.1 of this Act, be exercised by the State and may not be exercised by any unit of local government, including home rule units.⁸

For permits, exemptions and owner-builder rules, see Illinois building permits. To compare editions across states, see the code adoption map.