ADU Rules in Silver Spring, Maryland

Silver Spring is an unincorporated community in Montgomery County, Maryland, directly bordering Washington DC. There is no incorporated City of Silver Spring — it is a Census-Designated Place (CDP) and community identity, not a municipality. With a population of about 81,000 in the Silver Spring CDP, it is one of Maryland's most populous communities. All zoning and permitting is handled by Montgomery County, not a Silver Spring city government.

CRITICAL: No City of Silver Spring Government

Silver Spring is NOT an incorporated city. All ADU permits, zoning questions, and inspections go through:

• Montgomery County Department of Permitting Services
• Montgomery County Planning Department

Montgomery County ADU Rules

Montgomery County's Zoning Ordinance governs ADUs in Silver Spring. Montgomery County has been a leader in the DC region on ADU policy, allowing ADUs in residential zones to address housing affordability. Verify current ADU requirements with the Montgomery County Department of Permitting Services.

Permitted ADU Types

Per Montgomery County Zoning Ordinance (verify current standards):

• Accessory apartments (internal): Within primary structure
• Detached ADUs: Separate structure on the lot
• Garage conversions: Converting existing accessory structure

Verify current provisions with Montgomery County Planning.

Size Limits

Per Montgomery County (verify current standards):

• Maximum gross floor area
• Lot coverage restrictions

Setbacks

Per Montgomery County residential zone:

• Rear: Minimum setback
• Side: Minimum setback

Chesapeake Bay Critical Area and Stormwater

Properties near Rock Creek, Sligo Creek, or other waterways may have additional restrictions. Montgomery County has stormwater management requirements that may apply to ADU construction.

Historic Districts

Some Silver Spring properties are in historic districts or have historic designation. Verify historic status with Montgomery County Historic Preservation Office.

Permit Process

1. Verify zoning: Montgomery County Department of Permitting Services
2. Check stormwater/environmental: If near waterways
3. Historic review: If in a historic district
4. Submit plans: Montgomery County Department of Permitting Services
5. Building permit and inspections
6. CO: Required before occupancy

Contact

Montgomery County Department of Permitting Services 2425 Reedie Drive, Wheaton, MD 20902 Phone: (240) 777-0311 Website: montgomerycountymd.gov/permittingservices

Montgomery County Planning Department 2425 Reedie Drive, Wheaton, MD 20902 Phone: (301) 495-4610 Website: montgomeryplanning.org

Disclaimer: There is no City of Silver Spring — Montgomery County governs. ADU rules are evolving following Maryland's 2024 statewide legislation. Verify current standards with Montgomery County before starting any project.