Novato, CA Fence Regulations: Retaining Walls (2026)

Section 5-23.008(b)(2) sets the height cap: retaining walls not necessary as a structural element of a building shall not exceed a height of eight feet. Section 5-23.008(b)(5) governs the tops and toes of cut and fill slopes next to streets and driveways, and its street rule adds that retaining walls above street level must be at least 2.5 feet from the back of curb or nearest street improvement, while tops of banks must be at least four feet and toes at least two feet from the same point. The same subsection says street and driveway setbacks increase as needed for future sidewalks, parking, safe sight distance, driveway approaches, and utility installation.

The grading standards also limit the slopes a wall retains. Cut and fill slopes cannot be steeper than two horizontal to one vertical, slopes screened by structures or vegetation cannot exceed 16 feet, and slopes running along the depth of the lot or parallel to the front cannot exceed eight feet (section 5-23.008(b)(1)). Section 5-23.004 lists the processes the standards attach to, including building permits, grading permits, use permits, and encroachment permits.

On permits, section 106.2 of the building administrative provisions adopted in section 4-1.3 exempts retaining walls not over 4 feet in height, measured from the bottom of the footing to the top of the wall, and retaining not more than 3 feet of material, unless supporting a surcharge or impounding Class I, II, or IIIA liquids. In the zoning ordinance, section 19.20.040 says its fence regulations do not apply to retaining walls regulated by section 19.20.100 (Setback Requirements and Exceptions), requires a Building Permit for all fences and walls in the Flood Hazard (F3) overlay district, and measures fence height from the side with the lowest natural grade where grade differs on a slope or retaining wall. Grading beyond the thresholds in section 19.20.050 needs a Use Permit in addition to the grading permit.