Santa Clarita, CA Fence Regulations: Retaining Walls (2026)
Key Facts
- Side yard max height
- 6 feet (average slope under 10%)
- Rear yard max height
- 8 feet (average slope under 10%)
- Adjustment trigger
- Over 6 ft from neighboring parcel
- Permit-exempt height
- 4 ft footing-to-top (30 in. if sloped)
- Steep-slope lots
- 10%+ slope follows §17.51.020 instead
Summary
Santa Clarita caps retaining walls on typical residential lots (under a 10% average slope) at six feet in a side yard and eight feet in a rear yard, requires terracing above that, and sends walls over six feet measured from a neighbor's parcel to a Section 17.24.100 adjustment, while a separate building-code section exempts only short walls from a construction permit.
G. Retaining walls proposed on land with an average slope of less than ten percent (10%) shall be subject to the following provisions, as shown in Figure 17.57-6 (Retaining Walls). Retaining walls proposed on land with an average slope of ten percent (10%) or greater shall be subject to Section 17.51.020 (Hillside Development). 1. Where a retaining wall protects a cut below the natural grade and is located within a required yard, such retaining wall may be topped by a fence or garden wall. The fence or garden wall may be the same height that would otherwise be permitted at that location if no retaining wall existed; provided, that the subject property is on the lower side. In all other locations, the maximum height of the retaining wall and fence or screening wall combined shall not exceed the maximum heights established in this code or at the discretion of the Director. ... 4. Where a retaining wall is constructed to exceed six (6) feet in height measured from a neighboring parcel, an adjustment shall be obtained in accordance with Section 17.24.100 (Adjustments).
Full Breakdown
020 (Hillside Development). 070(G)(1)-(4), a retaining wall that holds back a cut below natural grade may be topped with a fence or garden wall of whatever height would otherwise be allowed at that spot, but where a wall holds fill above grade and sits in a required yard, a garden wall or fence built on top of it must step back one foot for every foot of its own height, with the gap between the two walls kept landscaped and maintained. 100. 030, Item 7) exempts a retaining wall from needing a building permit only if it is four feet or less from the bottom of the footing to the top of the wall, or 30 inches or less where it supports a slope or surcharge; interlocking 'keystone' dry-stack systems get a 36-inch (or 18-inch, if supporting a slope) exemption ceiling instead.
None of these permit exemptions apply on a slope steeper than 3:1, in a floodplain, or where the wall impounds a hazardous liquid, so any wall in those conditions needs a permit regardless of height.
Violations & Fines
Building a retaining wall above the height threshold without first securing a § 17.24.100 adjustment, or above the Building Code § 105.2 permit-exempt height without pulling a permit and engineering review, leaves the wall unpermitted; the Building Official or Director can order it stopped, corrected, or removed. An unpermitted or noncompliant wall is also a code violation and public nuisance under Municipal Code § 1.01.210, subject to summary abatement or a cost-recovery civil action under § 1.01.220.
Frequently Asked Questions
Do I need City approval to build a 5-foot retaining wall in my side yard?
What if my lot is on a hillside?
Can I stack two retaining walls to get more height?
Sources & Official References
Other rules in Santa Clarita
California rules heatmap·Compare Santa Clarita to another location·View the California fence regulations overview
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