ADUs & Additions in Santa Monica

City of Santa Monica Building and Safety Division (Community Development Department). Residential building, grading and swimming pool permits are issued by the city's own Building and Safety Division at the Permit Services Center, not by Los Angeles. Properties inside the coastal zone still need a coastal development permit from the California Coastal Commission, because the city has a certified Land Use Plan but not yet a fully certified Local Coastal Program; a memorandum of understanding with the Commission was signed in 2026 to complete it. Any demolition application for a structure more than 40 years old is transmitted to the Landmarks Commission for landmark review before it can move forward. Review durations vary by project and by whether coastal or historic review applies. We prepare the drawings, make the submittal and handle plan-check corrections ourselves, so you are not the one chasing the city.

Mostly flat, modest rectangular lots on a tight grid, many of them alley-loaded with shallow rear yards and close side-yard neighbors. Larger estate parcels appear north of Montana Avenue. In practice that means beach-side and Ocean Park parcels sit on sandy alluvium mapped for liquefaction, which pushes pool shells and ADU foundations toward deeper structural engineering..

All of it, including North of Montana, Sunset Park, Ocean Park, Wilmont. We are based in Los Angeles at Cahuenga Pass, so Santa Monica is a short run for our crews rather than a job we service from out of the area.

Detached ADU in this market generally runs $150,000 to $400,000+. What moves it is square footage, finish level, utility runs, and site access; garage conversions typically run well below a ground-up detached build. We give line-item pricing after seeing the site rather than quoting a number over the phone.

Plan a realistic year. Design and engineering typically take one to three months, city plan check and corrections add several more, and construction usually runs four to eight months depending on size and site access.

Usually yes, and often substantially, because the foundation, walls and roof already exist. The trade-offs are that you lose the garage, and older slabs and framing sometimes need upgrading to meet current code.

California ADU law is designed to allow long-term rental, and an ADU is one of the few ways to add rentable square footage to a single-family lot. Short-term rental rules vary by city, so confirm your local ordinance before counting on that income.

Yes. Plans, engineering, Title 24 and the city submittal are all handled in-house, including responding to plan-check corrections. That is a service we sell on its own, so it is not something we hand off.