ADUs & Additions in San Marino

City of San Marino Community Development Department, Building Division. Plan check, permits, and inspections are handled by the Building Division of the Community Development Department, which also staffs the city's Design Review Committee. That committee meets twice a month and reviews all new homes, all two-story additions, certain one-story additions, and architectural changes visible from public view. The tree preservation ordinance still requires a permit to remove any oak from any yard, or an established tree from a front or street-side yard, with substantial fines for unpermitted removal or damage. The Raymond Fault Alquist-Priolo Earthquake Fault Zone runs through the city, so mapped lots require a fault study before new living space is sited. We prepare the drawings, make the submittal and handle plan-check corrections ourselves, so you are not the one chasing the city.

Almost everything is single-family on large, level lots — typically a quarter acre to a full acre — with deep front setbacks, formal landscaping, and generous rear yards. In practice that means estate parcels carry dense mature canopy — oaks, camphors, magnolias — whose root plates and drip lines dictate where a pool, spa, or cabana can physically go..

All of it, including Lacy Park, Old Mill, Mission District, Huntington Library area. We are based in Los Angeles at Cahuenga Pass, so San Marino 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.