Planning commission backs zoning changes to implement San Bruno's housing element, debates ADU design rules

The San Bruno Planning Commission recommended that the City Council adopt zoning-code amendments to implement the city's adopted housing element and to update Title 12 to conform with recent state law changes.

Michael Smith, Planning Department staff, opened the presentation by saying the amendments are "phase one" of Program 11 and are intended to update definitions and code sections to reflect state law, including new entries for low-barrier navigation centers, single-room-occupancy units, emergency shelters and residential care facilities. He told commissioners the package also addresses parking, reasonable-accommodation findings and the density-bonus approach, and moves toward referencing state law where legislative changes are frequent.

Why it matters: the state has recently expanded ADU allowances and adjusted ADU-related development rules. Staff told the commission the local code must be updated to avoid conflict with state law and to preserve the city's ability to administer objective standards consistently.

Key changes and staff recommendations

- ADU quantity and height: Staff said a new state law effective January 2025 increases the allowance on certain multifamily parcels from two to as many as eight detached ADUs in some cases, and raises height limits near transit (from 16 to 18 feet, and to 20 feet when matching a primary-house roof profile). Michael Smith explained those changes as mandatory under state law and noted practical limitations for San Bruno's typical parcels.

- Occupancy and utilities: Staff said jurisdictions may no longer require owner occupancy for ADU owners, and cannot require separate meters for attached ADUs; detached ADUs may still have separate meters.

- Impact fees: Staff recommended not collecting impact fees on ADUs as an incentive, noting state law exempts the first 750 square feet from fee calculation. Commissioners discussed staff's example calculations and trade-offs; staff observed that the per-unit fee formula used for full new development can translate to large nominal figures for new multi-family doors but that ADU fee collection is often minimal in practice because of the 750-square-foot exemption.

Design standards and enforcement challenges

Smith told commissioners the city's residential design guidelines are largely non-objective and therefore hard to apply to ADUs, especially prefabricated units. He showed examples of prefabricated and built-in ADUs and said the city is seeing many kits with modern shed roofs and clearstory windows that are affordable but do not match traditional materials.

To address neighborhood impacts, staff proposed limited objective standards: require ADUs visible from the public right-of-way (for example on corner lots) to match the architectural style of the primary dwelling and require shed roofs to slope away from shared property lines so the highest roof point does not face neighbors. Staff recommended flexibility where ADUs are not visible from the street.

Commission discussion

Commissioners asked how frequently the new multifamily allowances would apply and whether trailers or units on chassis qualify; staff replied that foundations are required for ADU conversion and that the new law would be feasible only on certain larger multifamily parcels. Several commissioners raised equity concerns about fee waivers, noting waiving fees for ADUs could shift costs and incentives away from denser multifamily development. One commissioner called the state changes "a shock" to local practice and urged monitoring how developers apply the law.

Action and next steps

After discussion, the commission moved to approve a resolution recommending adoption of the ordinance amending Title 12 to implement the housing element and related ADU provisions. The motion passed on a roll call; the transcript records commissioners' affirmations but does not provide a granular numeric tally in the record excerpt.

The item will next go to the City Council for final action.

Ending

Staff noted the environmental review addendum to the housing element supports the amendments and described outreach and monitoring the city will undertake (including a new ADU monitoring survey required by HCD). Commissioners asked staff to continue refining objective elements where legally defensible and to return with any clarifying language before council review.