Planning Commission approves conditional use authorization at 4020 First Street after sponsor offers ADU revision

The San Francisco Planning Commission on April 11 approved a conditional use authorization for 4020 First Street, a single‑family home now proposing a modest third‑floor addition and a new accessory dwelling unit (ADU). Commissioner Braun moved to approve the revised project, and the motion passed 4–1 with Vice President Moore voting no.

Preservation planner Michelle Taylor told the commission the revised proposal adds approximately 402 square feet to the primary unit (totaling 2,981 square feet) and includes a 1,016‑square‑foot ADU. Taylor said the department found the project consistent with the General Plan and applicable design guidelines and noted it requires approval under planning code section 249.92 and related provisions.

Ryan Knock, the project sponsor and architect, described the ADU as a distinct ground‑floor unit with a private garden entrance, 9.5‑foot ceilings and an independent doorway. Knock said the project does not remove rental units and increases housing by one unit, from one to two.

Neighbors and professionals raised concerns that the work could amount to demolition and cited warning letters and demolition‑calculation issues. Steve Bain, an adjacent owner, said the plans contained misleading information and that excavation could destabilize his property. Architect Ray Willett urged enforcement of section 3.17, arguing the proposed structural work effectively replaces exterior facades.

Commissioners focused on whether the ADU had sufficiently independent access and whether the ADU’s elevation would allow the two units to be combined in the future. Vice President Moore said the ADU needed a separate house number and an enclosed approach and questioned whether the bathroom and foyer elevation created an easy path to merge units.

The architect offered a voluntary revision: remove the steps and lower the ADU bathroom to the same level as the rest of the ADU so the unit remains independent. Ms. Waddy and staff explained the ADU is also subject to state ministerial ADU rules. Commissioner Braun’s motion to approve the project included the sponsor’s offered revision; the motion was seconded and carried 4–1 with Moore dissenting.

The commission noted that Department of Building Inspection review and other technical checks (including fire and public‑works reviews) would still occur during building permit review. The commission’s approval permits the expansion and the ADU as described; Commissioner Williams did not participate in the hearing because she had not reviewed prior hearing materials.

The commission’s action concludes the matter for this hearing; the sponsor will proceed to the building‑permit stage, where DBI and other technical reviews will confirm structural and life‑safety compliance.