ADU Rules in Chevy Chase DC, Washington DC

Chevy Chase DC is an affluent residential neighborhood in upper Northwest DC (Ward 3), known for its large single-family homes, tree-canopied streets, and proximity to Rock Creek Park. It borders Chevy Chase, Maryland. DC Zoning Regulations (Title 11 DCMR) govern ADUs district-wide. The DC portion is subject to DC laws, not Maryland.

DC-Wide ADU Framework

DC Zoning Regulations govern accessory apartments across all DC neighborhoods. Chevy Chase DC's large lot sizes often make detached ADUs feasible.

Permitted ADU Types

• Detached Accessory Dwelling: Well-suited given large lot sizes
• Attached ADU: Addition with own entrance
• Garage Conversion: Converting existing garage
• Interior Conversion: Basement or upper floor

Zoning Context

Chevy Chase DC is primarily R-1-A and R-1-B (low-density single-family residential) — the most restrictive residential zones in DC. These zones have larger minimum lot sizes and greater setback requirements.

Size Limits

• Generally limited to 800 sq ft or percentage of primary dwelling
• Detached ADU limited by lot occupancy standards for the zone

Setbacks (R-1 Zones)

• Front: 25–30 feet minimum
• Side: 5–8 feet minimum
• Rear: 25 feet minimum

Height

• Detached ADU: Maximum 15 feet
• Cannot exceed height of primary dwelling

Note on Maryland Border

Properties at the DC/Maryland border are in DC jurisdiction. Confirm your address is in DC (not the Town of Chevy Chase, MD or other Maryland municipalities) before applying for DC permits.

Permit Process

1. Confirm jurisdiction: Verify property is in DC, not Maryland
2. Check zoning: Confirm zone via DC Interactive Zoning Map
3. DC Office of Zoning: Verify ADU eligibility for R-1 zone
4. Submit permit: DC Department of Buildings
5. Inspections and CO: Required before occupancy

Contact

DC Department of Buildings 1100 4th Street SW, Washington, DC 20024 Phone: (202) 671-3500 Website: dob.dc.gov

DC Office of Zoning 441 4th Street NW, Suite 200-S, Washington, DC 20001 Phone: (202) 727-6311 Website: dcoz.dc.gov

Disclaimer: Verify current DC Zoning Regulations with the DC Office of Zoning before starting any project. Confirm your property is in DC jurisdiction, not Maryland.