ADU Builder in Beverly Hills, California

Beverly Hills ADU Rules by Lot Type: Central Area, Hillside and Trousdale

Beverly Hills regulates ADUs in Article 50 of Title 10, Chapter 3 of its municipal code. Review is ministerial and happens during building permit plan check, but the city asks owners to sit down with a planner before they submit. We take that meeting early, with a site plan in hand, because a problem caught there costs a redline, not a rebuild.

In the Central Area, the second new ADU (the BHMC 10-3-5001 type) can be up to 1,400 square feet north of Santa Monica Boulevard and 1,200 square feet south of it, or whatever floor area the lot has left if that is smaller. Detached units can rise to 25 feet on the north side and 22 feet on the south side. An ADU of at least 800 square feet is allowed no matter what the floor area, coverage or front setback math says.

The Hillside Area plays by different rules. The same ADU type can still reach 1,400 square feet, but a detached one needs a front setback of at least 100 feet. That pushes most hillside units toward the back of a deep lot, into a converted structure, or into the house itself. Trousdale Estates adds its own Article 26 standards: a 14-foot height ceiling and no building past the edge of the level pad.

North of Sunset, and on a few blocks just south of it, the Beverly Hills Fire Department designates a Very High Fire Hazard Severity Zone. ADUs there get fire-resistant construction details, and the lots get annual brush clearance inspections that start on or after April 1. We place the ADU with those clearance zones in mind.

What Drives ADU Cost in Beverly Hills

We do not publish prices, because two ADUs of the same size here can cost very different amounts. The biggest swing is access. A Flats lot with a rear driveway lets a concrete truck and a small excavator reach the yard. A hillside pad reached by a narrow drive may need material moved by hand, a line pump for concrete, or a crane for framing packages.

Utilities are next. Beverly Hills runs its own water department, so a new water service or meter goes through the city, while power comes from Southern California Edison. Older homes often have panels too small to carry a second kitchen and a heat pump, and a service upgrade means coordinating with SCE on their schedule, not ours. Sewer laterals in 1920s and 1930s neighborhoods are frequently clay pipe that needs a camera inspection before anything ties into it.

Then there is the soil and the slope. Hillside sites usually call for a soils report and deeper foundations, sometimes caissons or grade beams. Fire-zone lots add ember-resistant vents, rated roofing and siding, and sometimes sprinklers. Finish level matters too, and in this market owners often want the ADU to match the main house in materials and detail. Size matters least of the major drivers. Keeping an ADU at or under 750 square feet does avoid impact fees under state law, which is worth weighing when you set the floor plan.