Preparing for retaining wall construction: an illustrative San Diego replacement, start to finish

Last Updated: October 27, 2026

Preparing for retaining wall construction mostly means preparing access: a clear path for material and equipment, an empty work zone along the wall, irrigation and utilities located, and neighbors told when the work runs along a shared line. The rest follows the permit sequence. To show how the pieces fit, Batterline San Diego Retaining Walls has laid out an illustrative replacement on a City of San Diego lot, stage by stage, with what the owner does to the yard at each step.

The example wall

Picture an old timber wall along the back of a level yard, about 40 feet long and about 4 and a half feet tall from the bottom of the timbers. The ties are rotting, the wall leans toward the house, and soil has started spilling through the gaps. There is lawn on the upper side, nothing heavier, and no visible drain. This is a replacement rather than a repair: rotted timber has no footing or drainage zone worth keeping, so patching the face would leave the cause in place. The repair or replace guide explains how that call is made on walls that are less clear-cut.

Stage 1: the first visit

The first visit measures the wall’s length, its exposed height and its height from the top of the footing, records the wall type and any lean, bulge or cracking, and looks for drains, weep holes and irrigation. It also notes what sits above the wall, which the City calls a surcharge, how equipment and material can reach the wall, and whether old permits or plans exist.

For the owner, this is when to mention anything that won’t show on a walk-around: a sprinkler line you know runs behind the wall, a sewer cleanout in the side yard, a pet that uses the yard, or a neighbor who has asked about the wall. Have the property’s permit history handy if you can get it.

Stage 2: choosing the design path

The replacement will stand over 3 feet from the top of its footing, so it needs a City building permit no matter what it is made of. The next question is whether it can use the City’s standard drawings. Information Bulletin 221 gives prescriptive designs for grouted, reinforced concrete block walls up to 6 feet, with level backfill or backfill up to 1.5:1, but not on expansive soil, with a surcharge, with a fence on top, or on ground the City’s Seismic Safety Study maps as a landslide, slide-prone formation, liquefaction or bluff hazard.

If the lot clears those checks, the example wall can be a standard block retaining wall with no engineer. If any check fails, the wall is designed by a California-licensed civil or structural engineer or architect, and in some mapped hazard categories a soils report comes first. The guide to whether you need an engineer covers those triggers. Height alone never settles it: the same 4-foot wall with a driveway above it is an engineered wall.

Stage 3: the permit

The application goes in electronically through the City’s online portal, with a site plan showing the wall’s length and height, its distance to structures, slopes and property lines, and where its drain discharges. Standard-design walls can use the City’s Rapid Review. Under the City’s current fee schedule, permit fees for one wall up to 50 feet run roughly $2,800 to $4,650, and a standard-design wall sits at the low end of that span. The cost guide breaks out each fee, and the construction timeline guide shows where review time falls.

Stage 4: getting the yard ready

This is the stage the owner controls, and it saves the most time on the first work day.

• The access path. Block, gravel, rebar and concrete come in, and old timbers and soil go out. Clear a path from the street to the wall, and say early if it runs through a narrow side yard or a gate. Where equipment can’t fit, material is carried by hand, which changes both the schedule and the price.
• The work zone. Excavation runs behind the wall as well as under it, because the footing, the gravel drainage layer and the backfill all sit there. Move pots, furniture, play equipment and anything stored against or above the wall, on both the high and low sides.
• Plants and irrigation. Decide which plants in the work zone you want to save and lift them, or accept that they will be removed. Show where sprinkler lines and valves run near the wall so they can be capped and rerouted rather than found with a shovel.
• Utilities. Buried utilities are marked through DigAlert, Southern California’s 811 center, before digging starts. Private lines the utilities don’t mark, such as a line to a garden light or a pool, are worth pointing out yourself.
• Neighbors. If the wall runs along a property line, or the excavation or access path comes near the neighbor’s side, tell them what is coming and when. Questions about who owns or pays for a shared wall are covered in the guide to who is responsible for a retaining wall.
• Daily life. Plan for pets and children to stay out of the yard while the excavation is open, and for a driveway or curb space to be used for deliveries.

Stage 5: demolition and excavation

The old wall comes out first, along with rotted timber, buried debris and soil that won’t work as backfill. Demolition and haul-off are worth seeing as separate estimate lines, because their cost depends on what the old wall turns out to contain. Excavation then opens the footing trench and the zone behind the new wall. Where an excavation reaches 5 feet or deeper and workers must enter it, Cal/OSHA requires the employer to hold an excavation permit.

Stage 6: footing and the first inspection

The footing is formed, the steel is tied, and the City inspects before any concrete is placed. The standard design specifies 3,000 psi footing concrete and Grade 60 rebar for most bars. Once the footing passes and the concrete is poured, block laying starts.

Stage 7: block, steel and the pre-grout inspection

Block goes up in running bond with vertical steel in the cells. Before grout fills those cells, the City inspects again, because once grout is in, the steel can’t be seen. Grout pours taller than 5 feet need cleanouts at the base.

Stage 8: drainage and the inspection that matters most

After grouting, the drain goes in: a 4-inch perforated pipe in a filter sock along the full length of the wall, a 12-inch gravel layer behind it from the top of the footing to 12 inches below finished grade, and an outlet carried to a stormwater collection system rather than onto a neighbor. The City inspects this before any earth backfill is placed. It is the last chance anyone has to see the drain, and it does more for the wall’s life than any finish. The retaining wall drainage page explains the system in more detail.

Stage 9: backfill, final inspection and restoration

Backfill goes in behind the gravel using the granular soils the standard design allows (GW, GP, SW or SP under the building code’s soil classes). The final inspection closes the permit. Then the yard is put back: irrigation reconnected and pointed away from the wall, the ground above graded to shed water, and planting replaced. Check whether the estimate includes that restoration or leaves it to you.

What would change in a different example

Put a driveway or a fence above the same wall, build it on clay or a mapped slide-prone formation, or make it 7 feet tall, and the wall moves out of the standard drawings into engineering, sometimes with a soils report and special inspections added. Swap block for a segmental wall and the design changes again, with geogrid layers that widen the excavation. The cost estimator shows how those changes move the budget, and you can ask for an estimate for your own wall with its address, dimensions and a photo of what sits above it.