IL HB4274

Amends Illinois Municipal Code Section 11-101-3 to require municipalities with Residential Sound Insulation Programs to conduct indoor air quality monitoring and laboratory analysis of installed windows and doors to identify health impacts from off-gassing.

Municipalities must develop science-based mitigation plans for significant health impacts and replace windows and doors in homes with offensive odors upon homeowner request, with a minimum replacement rate of 750 residences per year subject to appropriation.

Establishes an advisory committee with 9-10 members including affected homeowners, Department of Transportation representatives, municipal employees, and legislative appointees to determine which homes have odorous windows or doors and recommend replacement priority order.

Homeowners eligible for replacement can select window color and type, and the municipality must establish a showcase of available replacement windows at Chicago Midway International Airport; homeowners who previously made odor-related claims remain eligible for replacement.

Limits home rule units' ability to regulate indoor air quality monitoring and replacement requirements differently than specified in this Section; does not create a private right of action.