IL HB4887

Requires builders of newly constructed residential buildings (1-4 units) with permits issued on or after January 1, 2027 to complete an energy audit producing a Home Energy Rating System (HERS) Index Score before obtaining a Certificate of Occupancy.

Mandates sellers of existing dwellings (1-4 units) obtain a HERS Index Score energy audit and provide the report to buyers at least 10 business days before closing or contract execution.

Energy audits must be conducted by RESNET-certified Home Energy Raters and include blower door testing and duct leakage testing per ANSI/RESNET/ICC standards.

Non-compliance subjects builders or sellers to civil penalties up to $5,000 per violation and may invalidate property transfers.

Exemptions apply to foreclosures, family transfers without consideration, probate transfers, divorce-related transfers, and new construction already audited within 24 months.