SB 9 Duplex Architect in Glendale

California's SB 9 lets an eligible single-family lot hold two primary homes, and it allows an urban lot split that creates two lots with up to two units each. The state's housing department has confirmed that a lot without a split can hold two primary units even when it already has an ADU. Cities review these projects ministerially against objective standards; they cannot hold a discretionary hearing.

Not every lot qualifies. Lots in historic districts, lots with a rental unit removed in the last fifteen years, and parcels in certain hazard areas are excluded, and some hillside and fire-zone lots need a closer look. We run the eligibility check against your parcel before you spend money on design.

The best SB 9 projects read as two real houses: separate entries, private yards, their own parking, and equal light. The Montrose project on this site pairs two gabled volumes of the same size around a shared garden path. That approach also holds value if you decide to sell one unit later.

Eligibility and feasibility take two to three weeks. Design and the ministerial review typically run five to eight months, with a lot split adding a parcel map through the city's engineering division. Fees are quoted as a fixed fee per phase.

We also model the numbers with you: construction cost per unit, rental income or sale value, and the cost of the parcel map, so the decision between two units on one lot and a lot split is made on paper before it is made in drawings.