Journal

Do you need a permit for a retaining wall in San Diego?

Three feet is the familiar number. Where it is measured from, what sits behind the wall, and which building department covers your address change the answer.

8 min read

Inside the City of San Diego, a retaining wall needs a building permit when it is over 3 feet tall measured from the top of the footing, or when it holds back a slope steeper than 1.5 to 1, carries a surcharge such as a driveway or a fence, or is part of a tiered set over 6 feet (Information Bulletin 220). The unincorporated County and other cities set their own limits: Escondido, for one, counts 4 feet including the footing.

A wall can also be free of a building permit and still break a zoning height limit, because the City measures height two different ways. Below: which department is yours, the City's triggers, the two measurements, the standard-wall route, inspections, drainage, and how the County and Escondido differ.

First: whose rules apply to your address

Inside the City of San Diego, the City's Development Services Department and its Municipal Code apply.
In an unincorporated community, the County does: "The Building Services Division issues building permits for residential and commercial structures in the unincorporated areas of San Diego County."
Inside any other city, that city's building division sets the rule, and the numbers differ, as the table further down shows.

City of San Diego: the five triggers

IB 220 (October 2024): "Retaining walls require a building permit when any of the following conditions exist:"

"The wall is over three feet in height, measured from the top of the footing to the highest point on the wall."
"The wall supports a sloping backfill with a slope steeper than 1.5 horizontal:1 vertical."
"The wall supports surcharge loads. Surcharge loads include driveways, walkways, structure footings, fences, etc."
"The wall impounds flammable liquids."
"Tiered walls where the height measured from the bottom-tier wall's top-of-footing to the top of the top-tier wall is greater than six feet, or the footing of any tiered wall crosses the slope stability plane of a lower-tier wall."

The Municipal Code's exemption says the same from the other side: no building permit for "Retaining walls that are 3 feet in height or less, measured from the top of the footing to the top of the wall unless supporting a surcharge or impounding flammable liquids." Two cautions come with it. The exemptions "are not exemptions from the electrical, plumbing, and mechanical permit requirements," and an exempt wall must still be built to the rules: exemption "does not authorize any work to be done in any manner in violation of the provisions of the Building Regulations".

Two ways the City measures a wall

For the building permit, height runs from the top of the footing to the top of the wall. For zoning, it does not: "For zoning purposes, the height of a retaining wall is measured from the finished grade on the lower side of the retaining wall to the top of the retaining wall."

Zoning then limits that height by where the wall stands on the lot:

Front and street side yards: "Two retaining walls with a maximum height of 3 feet each are permitted in the required front and street side yard if the two retaining walls are separated by a minimum horizontal distance equal to the height of the upper wall."
Side and rear yards: two walls of up to 6 feet each, separated the same way.
Outside the required yards: "Retaining walls located outside of the required yards shall not exceed 12 feet in height."
In visibility areas: "Retaining walls in visibility areas shall not exceed 3 feet in height."

And the wall stays on your side of the line: retaining walls "shall be maintained within the applicant's property; encroachments into neighboring properties shall not be allowed."

When a permit is needed: the City's standard wall

The City publishes pre-engineered designs in Information Bulletin 221 (December 2023): "This bulletin offers design alternatives for the construction of masonry retaining walls not exceeding 6 feet in height with level or sloping backfills." Using them, IB 220 says, "Permits may be obtained by Rapid Review".

Not every wall qualifies. Walls on a slope steeper than 1.5 to 1, walls carrying a surcharge and walls holding flammable liquids "require a permit but are not eligible to use the standard retaining wall design".
Anything else is engineered: walls not fitting the bulletin "shall be designed by a civil engineer, structural engineer, or architect licensed in the State of California".
Soil can add a step: "A geotechnical investigation may be required depending on the project location."
Taller walls can add a permit: "Retaining walls higher than 5 feet may require a grading permit."
No fence on top of a standard wall: "Fences shall not be installed on top of the retaining wall designs specified in this document."

The four inspections on a permitted block wall

Footing: "once footing excavation procedures are complete and the reinforcing steel is securely tied in its final position, but before concrete is poured."
Pre-grout: "once the CMU blocks have been laid and the reinforcing steel is securely tied in its final position, but before the wall is grouted solid."
Backfill and drainage: "after grouting is completed and wall drains are in place, but before earth backfill is placed."
Final: "once all work has been completed."

Each inspection looks at work that the next step will cover up.

Drainage, permit or not

The City's standard design spells out the drain in detail:

"Wall drainage shall be installed along the length of the wall, and it shall consist of a perforated drain pipe with a minimum diameter of 4 inches, protected with a filter fabric sock."
"A 12-inch-wide layer of gravel shall be placed directly behind the retaining wall."
"The pipe shall discharge or connect to a stormwater collection system. Wall drainage discharging onto adjoining properties is prohibited."

Those lines come from the permitted standard design, but an exempt wall faces the same water, and the Municipal Code is clear that an exemption does not allow work that breaks the rules. Ask for the drain to be shown on any bid.

Unincorporated County and other cities

Jurisdiction	A wall that needs no building permit	Document
City of San Diego	"3 feet in height or less, measured from the top of the footing to the top of the wall unless supporting a surcharge or impounding flammable liquids"	Municipal Code 129.0203 (9-2026)
County of San Diego, unincorporated areas	"Walls that retain not over three feet of soil as measured from the top of the footing to top of retained soil, are not more than 6 feet in total height as measured from the lowest finished grade, and have a level backfill with no other structures within 6 feet and not supporting a surcharge or impounding flammable liquids."	PDS 110 (REV 01/01/2026)
City of Escondido	A permit is needed for retaining walls "except those lower than four feet including the footing and not supporting a surcharge"	Information Guideline 2 (April 2025)

Three agencies, three measurements: from the top of the footing, from the footing to the top of the retained soil with a 6-foot overall cap, and including the footing. The County's zoning sheet adds that "every retaining wall higher than 3 feet requires approval of a building permit", and limits solid walls and fences to 42 inches in front and exterior side setbacks and 72 inches in rear and side setbacks.

If your wall needs a permit, the person building it needs a license too: the state's $1,000 small-job exemption does not apply to work that requires a building permit. Our guide shows how to check a contractor license in a few steps, and how to read a construction estimate for the permit line. Planning a wall as part of a bigger backyard project? See our outdoor living work.

Quick answers

Do I need a permit for a 3-foot retaining wall in San Diego?

Inside the City, a wall 3 feet or less from the top of the footing, with nothing pressing on it from behind and no steep slope, is exempt from a building permit. At exactly 3 feet the City's code is not consistent, so confirm with Development Services. Over 3 feet, a permit is required.

How is retaining wall height measured in San Diego?

Two ways. For the building permit, from the top of the footing to the top of the wall. For zoning, from the finished grade on the lower side to the top of the wall, which is the number the yard limits (3, 6 and 12 feet) apply to.

Does a low wall next to a driveway need a permit?

It can. IB 220 lists driveways, walkways, structure footings and fences behind a wall as surcharge loads, and a wall supporting a surcharge needs a building permit at any height. It also cannot use the City's standard design.

Do I need an engineer for a retaining wall?

Not if the wall fits the City's standard masonry designs in IB 221 (up to 6 feet, level or sloping backfill). Walls outside those designs must be designed by a California-licensed civil or structural engineer or architect, and a geotechnical investigation may be required.

What inspections does a permitted retaining wall get?

Under the City's standard design, four: footing (steel tied, before concrete), pre-grout (block laid, steel tied, before grout), backfill and drainage (drains in, before backfill), and final.

What is the rule in unincorporated San Diego County?

The County exempts walls retaining no more than 3 feet of soil measured from the top of the footing, no more than 6 feet tall overall from the lowest grade, with level backfill, no structures within 6 feet and no surcharge. The County's zoning sheet says walls over 3 feet require a building permit.

Can I put a fence on top of a retaining wall?

Not on the City's standard wall designs, which say fences shall not be installed on top of them. A fence behind or on a wall also counts as a surcharge, which brings a permit and an engineered design.

Sources

Information Bulletin 220: How to Obtain a Permit for a Retaining Wall Using the City of San Diego Standard Drawings and Specifications (City of San Diego Development Services)
Information Bulletin 221: Standard Cantilevered Retaining Walls (City of San Diego Development Services)
San Diego Municipal Code 129.0203, Exemptions from a Building Permit (Ch. 12, Art. 9, Div. 2) (City of San Diego)
San Diego Municipal Code 142.0340, retaining wall heights in required yards (Ch. 14, Art. 2, Div. 3) (City of San Diego)
Building Services Division (County of San Diego, Planning & Development Services)
PDS 110: Building Permit Requirements per Adoptive Ordinance (County of San Diego, Planning & Development Services)
PDS-308: Walls/Retaining Walls (County of San Diego, Planning & Development Services (Zoning))
Information Guideline 2: Retaining Walls (City of Escondido Building Division)
Business and Professions Code 7048 (California Legislative Information)

Read on 2026-10-16.