IL SB4060

Amends the Illinois Municipal Code to require municipalities to allow middle housing (duplexes, triplexes, fourplexes, cottage clusters, townhouses, and courtyard housing) as of right in all residential zoning districts that permit single-family homes, with unit allowances scaled by lot size: up to 4 units on lots 2,500-5,000 sq ft, up to 6 units on lots 5,000-7,500 sq ft, and up to 8 units on lots over 7,500 sq ft.

Caps minimum lot sizes at 2,500 square feet for single-family homes and prohibits municipalities from imposing more restrictive development standards on middle housing than on single-family dwellings, including requirements for discretionary review such as special use permits or public hearings.

Limits parking mandates to 0.5 spaces per multifamily unit and eliminates parking requirements for units under 1,500 sq ft or properties within one-half mile of public transit.

Requires municipalities to allow conversion of existing residential structures to middle housing if expansion is limited to 50% of floor area or 1,200 sq ft (whichever is greater) and the conversion complies with building codes and landmark laws.

Establishes an 8-month compliance period after the effective date, after which municipalities that fail to adopt conforming zoning amendments must follow default state standards including maximum setbacks (10 ft front/rear, 5 ft sides), minimum 35-foot building height, and 70% lot coverage limits.