ADU Rules in Champaign, Illinois

Champaign is a Champaign County city with a population of about 90,000, located in east-central Illinois. It is home to the University of Illinois Urbana-Champaign (UIUC) — one of the nation's top public research universities. The university creates a large rental housing market. Adjacent Urbana is a separate city with its own zoning code. Illinois has no statewide ADU preemption law — Champaign's local zoning governs.

Champaign Zoning Code

The City of Champaign Zoning Ordinance governs all land use. Residential zones near the university have significant rental housing activity, and ADU regulations are shaped partly by this context.

Permitted ADU Types

Depending on the residential zone:

• Accessory apartments: Interior or attached conversions within single-family or two-family structures
• Detached accessory dwelling units: In rear yards of eligible zones

Champaign's proximity to UIUC means many neighborhoods have higher-density residential zoning. Verify specific ADU allowances with the Planning Division.

Size Limits

Accessory dwelling units are subject to:

• Maximum floor area limits per zone
• Lot coverage restrictions

Verify current standards with Champaign Planning and Development.

Setbacks

Per Champaign residential zone (typical):

• Rear: Minimum setback
• Side: Minimum setback
• Accessory structures: Generally smaller setbacks than primary structure

University Proximity and Rental Market

Neighborhoods near UIUC have strong rental demand. If planning an ADU as a rental unit, verify:

• Champaign rental licensing requirements
• Property registration requirements for rental units
• Zoning district allowances for rental occupancy

Note: Urbana is Separate

If your property is in Urbana, you must contact the City of Urbana Planning Division — not Champaign — for zoning and permits. UIUC's campus address can be in either city.

Permit Process

1. Verify jurisdiction: Confirm whether your property is in Champaign or Urbana
2. Verify zoning: Champaign Planning and Development
3. Submit plans: Champaign Building Safety Division
4. Rental registration: If applicable
5. Building permit and inspections
6. CO: Required before occupancy

Contact

City of Champaign Planning and Development Department 102 North Neil Street, Champaign, IL 61820 Phone: (217) 403-7230 Website: champaignil.gov

Disclaimer: Illinois has no statewide ADU law. Champaign and Urbana are separate municipalities. Verify current ADU allowances with the City of Champaign before starting any project.