Do you need a permit for a retaining wall in Denver, CO?
It depends on the details of your project.
Walls shorter than 12 in need no permit.
Walls 12 in and taller need a zoning permit.
Walls over 4 ft also need a building permit.
A person last checked these rules on October 19, 2026. This is guidance only, so confirm with Denver 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 Denver
| Permit | When it applies |
|---|---|
| Zoning permit | Denver requires a permit for any wall 12 in or taller. |
| Building permit | Walls over 4 ft tall also need a building permit. |
| Floodplain development permit | Grading and walls in a FEMA special flood hazard area need a floodplain permit. |
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
- Denver e-permits (Accela)
- Single-family and duplex projects
- Denver zoning map
- Denver Zoning Code
- Phone: 311 (720-913-1311)
Common questions
- When does a retaining wall need a building permit in Denver?
- Walls over 4 ft tall also need a building permit. Walls 4 ft or less need only the zoning permit.
- Do I also need a zoning permit for a retaining wall in Denver?
- Denver requires a permit for any wall 12 in or taller.
- Where do I apply for a retaining wall permit in Denver?
- Apply through Denver e-permits (Accela), or call 311 (720-913-1311).
Sources
- Denver CPD, Fences and Walls. Checked 2026-10-19
All fences over four feet tall need a zoning permit... Post-hole dug fences only need a building permit if they are taller than eight feet, but all other fence and wall types require building permits if they are over four feet tall.
- 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...