Retaining Walls: Phoenix vs Tempe
How do retaining walls rules compare between Phoenix, AZ and Tempe, AZ?
Phoenix and Tempe have similar restriction levels.
Phoenix, AZ
Maricopa County
Phoenix requires building permits for retaining walls over 3 feet in height. Combinations of retaining walls and fences always require structural design calculations. Combined wall-fence structures exceeding 9 feet need zoning approval. Walls 3 feet or less are exempt from permits unless on hillside lots.
View full Phoenix rules →Tempe, AZ
Maricopa County
Tempe requires building permits for retaining walls over 4 feet in height. Walls exceeding 4 feet must be designed by a licensed engineer. Combined height of retaining wall and fence on top counts toward height limits. Retaining walls must not redirect drainage onto neighboring properties. The building code (Chapter 8) and Zoning and Development Code govern retaining wall construction.
View full Tempe rules →Key Facts Comparison
| Fact | Phoenix | Tempe |
|---|---|---|
| Permit Threshold | Over 3 ft requires permit | Over 4 ft requires building permit |
| No Permit Needed | 3 ft or less (non-hillside) | - |
| Combo Walls | Always require structural calcs | - |
| Zoning Approval | Required if combo exceeds 9 ft | - |
| Hillside Lots | All retaining walls need permits | - |
| Engineering | - | Required for walls over 4 ft |
| Combined Height | - | Wall + fence counts toward zoning limits |
| Drainage | - | Must not redirect water to neighbors |
| Soils | - | Expansive clays in some Tempe areas |
| Governing Code | - | Chapter 8, Zoning and Development Code |
Highlighted rows indicate differences between cities.
Phoenix FAQ
Do I need a permit for a retaining wall in Phoenix?
Unsurcharged retaining walls 3 feet or less do not require a permit (unless on a hillside lot). Walls over 3 feet require a building permit with structural design calculations. Combined retaining wall/fence structures always require structural calculations.
How is retaining wall height measured?
Height is measured from the bottom of the footing to the top of the wall, not from the top of the soil. A railing or view fence on top of a retaining wall is permitted up to 40 inches if needed for pedestrian safety.
Tempe FAQ
Do I need a permit for a retaining wall in Tempe?
Walls over 4 feet high (measured from footing to top) require a building permit and engineered plans. Walls 4 feet or less are generally permit-exempt.
Can I add a fence on top of my retaining wall?
Yes, but the combined height counts toward zoning limits.
What about drainage behind the wall?
Proper drainage (weep holes or drainage systems) is required to prevent hydrostatic pressure. The wall must not redirect water onto neighbors.
Compare other topics
See how Phoenix and Tempe compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool