ADUs & Additions in San Gabriel

City of San Gabriel Community Development Department, Building and Safety Division. Building permits are issued by the Building and Safety Division of the Community Development Department at City Hall, 425 South Mission Drive, and Planning Division approval usually comes first: a new house or a second-story addition to a one-story house goes to the Design Review Commission for Site Plan Review, while first-floor additions and ADUs are reviewed by Planning staff. Removing a mature Class 1 tree, or cutting away more than a third of its live foliage, requires a Tree Removal/Trimming Permit that the Community Development Director may grant only on specific findings. Under the 2017 Historic Preservation and Cultural Resource Ordinance, alterations to properties on the city's Register need an initial review for historic appropriateness, new construction inside a Register-listed historic district goes to the Historic Preservation and Cultural Resource Commission, and a permit to demolish a building 45 or more years old is generally referred to the Community Development Director for a preliminary determination of whether it meets criteria for historic designation. We prepare the drawings, make the submittal and handle plan-check corrections ourselves, so you are not the one chasing plan check.

In the R-1 single-family zone, newly created lots must be at least 7,260 square feet and 50 feet wide (55 feet on a corner), and lot coverage is capped at 35 percent of net lot area, a figure that counts the house, covered and uncovered patios, raised and at-grade decks, paved surfaces wider than 42 inches other than required driveways, gazebos and pool equipment rooms. Rear yards must be at least 25 feet deep, a detached accessory building may cover no more than half of that yard, and a pool house or any other accessory building besides a garage is limited to 200 square feet, with ADUs governed by their own rules. One local condition that shapes the work: Class 1 trees, a list that includes oaks, sycamores, camphors and jacarandas, are protected once mature: on a single-family lot that means a trunk over 30 inches in circumference, measured four feet above natural grade, in a side or rear yard, or over 19 inches in a front yard. Removing one needs a permit granted only on specific findings, so a pool or ADU footprint is best planned around existing canopy from the start.

All of it, including Mission District, Rosemont Park, Country Club Crest and Old Mill Vista. Our crews run every job out of our Cahuenga Pass base in Los Angeles, with our own people on site.

Detached ADU: generally $150,000 to $400,000+ across Southern California. 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.