Capital Development Board 
William G. Stratton Building 

401 S. Spring St. 
Third Floor 
Springfield, IL 62706 
Building Codes and Regulations – Illinois Codes

Adopted I-Codes:
2021 International Building Code (IBC)
2021 International Energy Conservation Code (IECC)
2021 International Residential Code (IRC)
Applicability (statewide, local, limited): LIMITED

There is no State level plan review, enforcement, or inspection. Local municipalities and counties are free to adopt or not adopt codes. In jurisdictions that are not covered by codes, Illinois Public Act 96-0704 mandates the use of the 2006 or newer version of the IBC for commercial construction. In those municipalities that have adopted building codes, those adopted range from the 1990 BOCA Building Code to the 2021 IBC and IRC.  


Tall Mass Timber Adoption

The tall mass timber provisions went into effect in 2023 for the following jurisdictions:  Calumet City, Edwardsville, Hanover Park, Justice, Kane County, Lake in the Hills, Libertyville, Montgomery, Mt. Morris, Oak Brook, Plainfield, Rock Falls, St. Charles, Sleepy Hollow and Wilmington.


Expected date most recent code will be adopted:

Unknown.  Some jurisdictions adopt updated codes regularly and some do not. 


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Page last updated: December 2023