Retaining Walls: Concord vs Oakley
How do retaining walls rules compare between Concord, CA and Oakley, CA?
Concord and Oakley have similar restriction levels.
Concord, CA
Contra Costa County
Retaining walls in Concord over 4 feet in height (measured from bottom of footing) or supporting a surcharge require a building permit and engineered plans. Walls under 4 feet are generally exempt from permits but must still meet property line setbacks. All walls must comply with grading and drainage requirements.
View full Concord rules →Oakley, CA
Contra Costa County
Retaining walls up to 3 feet (measured footing to top) are exempt from building permits in unincorporated Contra Costa County. Combined with a fence, the total height may not exceed 7 feet, and the wall portion may not exceed 3 feet.
View full Oakley rules →Key Facts Comparison
| Fact | Concord | Oakley |
|---|---|---|
| Permit Threshold | Over 4 ft from footing, or any surcharge | - |
| Permit Authority | Concord Building Division | - |
| Engineered Plans | Required for walls over 4 ft | - |
| Combined Height | Fence + wall counted from low side | - |
| Stormwater | NPDES construction compliance for grading | - |
| Retaining wall exemption | - | Up to 3 feet |
| Combined fence + wall | - | 7 feet total, wall ≤ 3 ft |
| Code Section | - | Ord. Code 72-6.202 |
Highlighted rows indicate differences between cities.
Concord FAQ
Do I need a permit for a 3-foot retaining wall?
Generally no, as long as the wall does not support a surcharge (load from structures, slopes, or vehicle loads). Zoning setbacks still apply.
What counts as a surcharge?
A surcharge is any additional load on the wall beyond self-weight: sloping fill above the wall, a driveway or building, or soil pressure from adjacent grading.
Can I put a fence on top of a retaining wall?
Yes, but the combined height of the wall and fence is measured from the low side grade for code compliance. Engineering review may be required.
Oakley FAQ
Can I stack a fence on top of a 3-foot retaining wall?
Yes, as long as the combined height of the wall and fence does not exceed 7 feet and the wall portion stays at or under 3 feet. This combined structure may be placed within required yard setbacks without planning approval.
When does a retaining wall need an engineered permit?
Whenever it exceeds 3 feet from footing to top, supports a surcharge (such as a driveway or sloped backfill steeper than 1:2), or impounds Class I, II, or III-a liquids.
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