Retaining wall contractor for Bay Area slopes.

What does a retaining wall do for a Bay Area yard?

It turns a slope you cannot use into flat ground you can. Most of the walls we build do one of three jobs: hold back a hillside that is slowly moving toward the house, cut a level pad for a patio or lawn, or terrace a steep backyard into two or three usable levels.

Lots in Orinda, the Oakland hills, San Anselmo and much of Marin were graded decades ago with timber walls that are now rotting out. Segmental block is what we replace them with.

Why segmental block instead of poured concrete or timber?

A segmental wall is built from interlocking concrete blocks stacked without mortar. Each block can shift a fraction of an inch, so the wall moves with the ground during an earthquake and settles back. A rigid poured wall cracks under the same movement.

• Flexes with seismic movement and with clay soil that swells in winter.
• Drains through the joints and the gravel column behind it, so water pressure does not build up.
• No rot, no termites and no rusting rebar, which is what ends most timber walls.
• Matches the paver patio, steps and seat walls built next to it.

How do we build a wall that stays put?

Walls fail from behind. Water collects in the soil, the pressure builds, and the wall leans or bulges. Almost everything that matters in our build is something you will never see once the job is finished.

• A compacted gravel footing, with the first course of block buried below grade.
• Clean drain rock behind the full height of the wall and a perforated pipe at the base that carries water out to daylight.
• Filter fabric between the drain rock and the native soil so the drainage does not clog with fines.
• Geogrid reinforcement tied back into the slope on taller walls or walls carrying a load.
• Backfill compacted in lifts of a few inches at a time, never dumped in at once.
• Caps glued down and the grade behind the wall shaped so surface water runs away from it.

Do you need a permit or an engineer for a retaining wall?

In most Bay Area cities a wall over four feet tall needs a permit and an engineered design. The four feet is measured from the bottom of the footing to the top of the wall, so a wall that looks three feet tall from the patio can already be over the line.

A driveway, parking pad, pool or uphill slope behind the wall is called a surcharge, and it lowers the height at which the city asks for engineering. We check the rule for your city during the estimate, bring in the engineer when one is required and build to the stamped drawings.

How much does a retaining wall cost in the Bay Area?

Walls are priced per square foot of wall face, which is length times height. In 2026 our segmental block walls run about $60 to $85 per square foot under three feet, $75 to $100 between three and four feet, and $90 to $120 or more for engineered walls over four feet.

As a reference, a 40-foot garden wall two and a half feet tall in a flat yard with good access lands around $6,000 to $8,500. A 50-foot wall three and a half feet tall with geogrid in clay soil lands around $13,000 to $17,500. Engineered walls below a driveway are priced as a project and commonly start at $30,000.