Do you need a permit for a retaining wall in Montgomery County, MD?
It depends on the details of your project.
Retaining walls up to 48 in, measured from the bottom of the footing, need no permit unless they support a surcharge.
Land disturbance over 5,000 sq ft or 100 cubic yards needs a sediment control permit.
A wall or fence on a corner lot is limited to 3 ft above the curb within 15 ft of the corner.
A person last checked these rules on October 20, 2026. This is guidance only, so confirm with Montgomery County before you build.
Check your exact lot
Your zoning district sets the setbacks, and a flood zone can change the permit answer. Enter your address to see both.
Permits a retaining wall can need in Montgomery County
| Permit | When it applies |
|---|---|
| Building permit | Montgomery County exempts only retaining walls up to 48 in from the bottom of the footing that support no surcharge. |
| Sediment control permit | Land disturbance over 5,000 sq ft, or 100 cubic yards of earth movement, needs a sediment control permit. |
| Floodplain development permit | Grading and walls in a FEMA special flood hazard area need a floodplain permit. |
| Historic Area Work Permit (HPC) | On a Master Plan historic site or in a historic district, exterior changes need a Historic Area Work Permit from the Historic Preservation Commission before DPS issues other permits. |
Local details
- Call 811 at least a few days before you dig footings or post holes. Utility locating is free.
- HOA covenants and deed restrictions can be stricter than city rules. Check yours before you build.
How to apply
- DPS eServices
- Department of Permitting Services
- MCAtlas zoning map
- Phone: 311 (240-777-0311)
Common questions
- When does a retaining wall need a building permit in Montgomery County?
- Montgomery County exempts only retaining walls up to 48 in from the bottom of the footing that support no surcharge. A retaining wall 48 in or less from the bottom of the footing, with no surcharge, needs no permit.
- Where do I apply for a retaining wall permit in Montgomery County?
- Apply through DPS eServices, or call 311 (240-777-0311).
Sources
- Montgomery County DPS, Permits Required list (land disturbance). Checked 2026-10-21
Land Disturbance (greater than 5,000 square feet or 100 cubic yards or more of earth movement) [likely requires a permit].
- 44 CFR 59.1, definition of development (NFIP). Checked 2026-10-19
Development means any man-made change to improved or unimproved real estate, including but not limited to buildings or other structures...
- 44 CFR 60.3, floodplain management criteria. Checked 2026-10-19
Require permits for all proposed construction or other development in the community...
- Montgomery Planning, Historic Area Work Permits. Checked 2026-10-21
Work requiring a HAWP includes but is not limited to the following: [new construction, additions, removing porches and other exterior work on Master Plan historic sites and properties in Master Plan historic districts, reviewed by the Historic Preservation …