ADU Rules in Des Plaines, Illinois

Des Plaines is a Cook County city with a population of about 58,000, located immediately east and north of O'Hare International Airport. It is a fully incorporated municipality with its own zoning code. Illinois has no statewide ADU preemption law — Des Plaines's local zoning governs.

Des Plaines Zoning Code

The City of Des Plaines Zoning Ordinance (Title 13) governs all land use. The city has a mix of residential neighborhoods, commercial corridors, and industrial areas near O'Hare.

Permitted ADU Types

Depending on the residential zone:

• Accessory apartments: Within or attached to primary structure
• Detached accessory structures: Subject to setback and lot coverage limits

Verify current ADU-specific allowances with the Des Plaines Community and Economic Development Department.

Size Limits

Accessory dwelling units are subject to:

• Maximum floor area per zone
• Lot coverage restrictions

Verify current limits with the city.

Setbacks

Per Des Plaines residential zone (typical):

• Rear: Minimum setback
• Side: Minimum setback
• Accessory structures: Per ordinance standards

O'Hare Airport Proximity

Des Plaines is directly adjacent to O'Hare International Airport. Considerations include:

• Noise impact areas: Some properties are in O'Hare noise impact zones — soundproofing may be required or recommended
• Avigation easements: Some properties near the airport may have avigation easements affecting development
• Property acquisitions: Some Des Plaines parcels were acquired by the city/airport authority for noise mitigation

Verify your property's status and any overlay restrictions with the city.

Des Plaines River Floodplain

Parts of Des Plaines near the Des Plaines River may be in FEMA flood zones. Verify flood map status for your property.

Permit Process

1. Verify zoning: Des Plaines Community and Economic Development
2. Check O'Hare overlay: If near the airport
3. Check flood zone status: If near the Des Plaines River
4. Submit plans: Des Plaines Building Division
5. Building permit and inspections
6. CO: Required before occupancy

Contact

City of Des Plaines Community and Economic Development 1420 Miner Street, Des Plaines, IL 60016 Phone: (847) 391-5380 Website: desplaines.org

Disclaimer: Illinois has no statewide ADU law. Des Plaines zoning governs locally. O'Hare proximity may affect some properties. Verify current ADU allowances with the City of Des Plaines before starting any project.