Hillside patios and retaining walls in San Anselmo, CA
Marin lots are beautiful and rarely flat. On our San Anselmo project the only usable space was a narrow strip by the back door. A segmented block retaining wall turned the slope into a level patio, a lawn and walkways that connect the levels.
2026 pricing · Financing available
Retaining walls $60 – $120 per sq ft of wall face
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What went into the San Anselmo project?
The backyard sloped away from the house steeply enough that nobody walked on most of it. We built a segmented block retaining wall to hold the upper level, filled the new flat area with a paver patio, and added paver walkways and stepping stones for the last of the grade change.
The patio base was tied into the wall backfill, so the wall, the patio and the walkways drain and move as one system instead of three separate builds.
What does a Marin hillside wall need that a flat-lot wall does not?
Water is what pushes walls over. Behind every wall we place drain rock wrapped in fabric and a perforated pipe at the base that carries water out. Backfill goes in a few inches at a time and is compacted before the next layer.
Walls above roughly 3 to 4 feet, or walls holding a driveway or slope above them, get geogrid reinforcement. In most Bay Area cities, walls over 4 feet measured from the bottom of the footing need an engineer and a permit, and we handle both.
- Segmented block, under 3 ft: $60 – $85 per sq ft of wall face
- Segmented block, 3 – 4 ft: $75 – $100 per sq ft of wall face
- Engineered wall, over 4 ft: $90 – $120+ per sq ft of wall face
Why does access change the price so much in San Anselmo?
On a hillside in San Anselmo or Mill Valley, base rock and block often go up or down by hand. That is a large share of the labor, so we plan how material reaches the wall during the estimate and price it in writing.
Your pavers in San Anselmo, paid over time.
Free on-site estimate, itemized in writing. Ask about financing when we visit.
Our work in San Anselmo
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The flat patio the wall created, built on 8,000 PSI pavers over a compacted base. 
Segmented block retaining wall holding the slope, with drain rock and a perforated pipe behind it.
San Anselmo: frequently asked questions
How much does a retaining wall cost in San Anselmo?+
Most segmented block retaining walls run $60 to $120 per square foot of wall face installed in 2026, depending on height, soil, drainage and access. Hand-carried material on Marin hillsides pushes the number up.
Do I need a permit for a retaining wall in Marin County?+
In most Bay Area cities, walls over 4 feet measured from the bottom of the footing, or any wall supporting a surcharge such as a driveway or slope, need a permit and an engineer's design. We confirm the rule for your address and handle it as part of the project.
Why do retaining walls lean?+
Almost always water. Without drainage behind the wall, saturated soil pushes against it until it leans. Thin footings and poor compaction are the other common causes.
Can you build the patio and walkways at the same time as the wall?+
Yes, and it usually costs less than doing them separately, because the crew, the equipment and the excavation are already on site. On the San Anselmo project the patio base was tied into the wall backfill.
Is financing available for a retaining wall project?+
Yes, financing is available. Ask during your free on-site estimate.
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Planning a project in San Anselmo?
Send us a quick description and a couple of photos. We come measure on-site, talk through the options for your space and budget, and write up a clear estimate. Financing available.