Retaining Walls in Brentwood, CA

National cost guides put the average at roughly $35–$65 per square foot of wall face including labor (HomeGuide), and Angi lists a national average project of about $6,084 with a typical range of $3,192–$9,206. Height, material, footing, drainage, engineering and access move the price a lot. Our cost guide shows the sources and works through 4 ft x 20 ft, 5 ft x 30 ft and 100 ft examples.

The City of Brentwood's municipal code says a building permit is required for retaining walls over four feet high, measured from the bottom of the footing to the top of the wall, and for walls supporting a surcharge such as a steeply sloped surface. Walls over four feet may also be limited, or need a geotechnical report. Read the quoted code on our permit guide and confirm with the City before you build.

Concrete, masonry, landscape and general contractors all advertise retaining walls. Which license class fits a particular wall depends on the job, so check any contractor's license, classification and status at cslb.ca.gov and ask them to put the scope in writing. Our contractor guide has a bid checklist.

Common warning signs are leaning or bulging, stair-step or wide cracks, gaps at the cap, water or soil collecting at the base, and fences or paving above the wall that are tilting or settling. We can't diagnose a wall. If any of these show up, have a licensed contractor or engineer evaluate it, and sooner if the wall is near a structure, a pool or a driveway.

It depends on height, soil, drainage, budget and looks. Concrete and engineered block suit taller or heavily loaded walls, segmental block and stone suit visible garden walls, and wood is generally the shortest-lived option because of rot. Our materials guide compares them without brand recommendations.