The San Mateo County Board of Supervisors adopted stricter affordable housing requirements for three rezoned districts in unincorporated San Mateo County and took positions on two November ballot measures at its Tuesday, Oct. 6 meeting.

The board amended its inclusionary housing ordinance for the R3-MD, PC-HD and TS-MU zoning districts, which were adopted April 21 to allow high-density multifamily development under the county's Housing Element. The change requires developers in those districts to build all required affordable units on site. Previously, the county could authorize alternatives, including in-lieu fees, land dedication or affordable units at a different location.

The amendment also eliminates provisions that allowed some smaller rental projects and some ownership projects to satisfy part of the county's 20% affordability requirement with moderate-income units instead of low-income units. Under the new rules, all required affordable units must serve households at or below the low-income level.

Steve Monowitz, the county's planning and building director, said in a staff report that the changes bring the three districts into compliance with state law. The amendment applies only to projects in those rezoned areas and does not change inclusionary rules elsewhere in unincorporated San Mateo County.

Prop 43 opposition

The board also adopted a resolution opposing Proposition 43, which would amend the state Constitution to require two-thirds voter approval for voter-initiated local special taxes beginning Jan. 1, 2027. Under current law, voter-initiated special taxes need only a simple majority.

County Executive Michael P. Callagy and Chief Legislative Officer Connie Juarez-Diroll recommended the opposition, writing in a staff report that the measure could reduce county revenues over time by making it harder to establish or extend voter-approved local taxes.

The county's 2026 legislative program supports lowering the voter-approval threshold for special taxes, a position Prop 43 would undercut.

Prop 1 endorsement

Supervisors endorsed Proposition 1, the Veterans and Affordable Housing Bond Act, which would authorize $11.25 billion in state bonds for housing programs. Supervisors Lisa Gauthier and Noelia Corzo co-sponsored the resolution.

The county Department of Housing estimates that projects already in its pipeline will need more than $90 million from the state's Multifamily Housing Program alone. About 1,000 additional homes are in predevelopment and still need public funding before construction can begin, according to the staff report.

Since 2012, the county's Affordable Housing Fund has financed more than 5,100 affordable homes, according to the report.

Voters will decide both propositions on the Nov. 3 general election ballot.