Portola Valley ASCC reviews proposed mixed-use high-density zoning; raises concerns about minimums, setbacks and tree impacts

Sarah Horst, the town of Portola Valley’s planning and building director, presented a draft mixed-use high-density (MUHD) zoning and implementing materials tied to a housing element amendment that would reallocate housing units from Dorothy Ford Field to three sites: Village Square, Christchurch and Skyline Open Space. Horst said the amendment (submitted to the California Department of Housing and Community Development, HCD, on Jan. 23) would allow residential uses by right, permit commercial uses with a conditional use permit and require that residential occupy at least 50% of total floor area.

The commission’s primary concern centered on the draft district’s minimum density and how the zoning would be applied. A committee member told the commission the three sites are “quite different,” noting Skyline is about 13 acres served by septic, Christchurch relies on parking for religious gatherings, and Village Square contains an approximately 14,000-square-foot building, a pumping station and long‑running tenants. The member urged site-by-site study, arguing that applying a parcel‑wide minimum (the draft references a 20‑units‑per‑acre minimum discussed as a state requirement) could make compliance infeasible: “If you applied that minimum…you'd be looking at over 200 [units]” on larger parcels, the member said, and that could force multistory buildings or subdivision to avoid the minimums.

Horst said staff has done analysis of developable areas and setbacks and that the current rezoning proposal is parcel‑based—that is, applied to assessor parcels—while acknowledging the differences between assessor parcel area and physical developable area. “There’s not a proposed project per se,” Horst said, adding staff will provide slide materials and follow up with more detail as HCD completes its first review. She recommended clarifying the draft to show how special setbacks and developable-area constraints were accounted for.

Commissioners asked for a clearer definition of floor area (net vs. gross) and highlighted coverage and floor‑area relationships (the draft lists a 35% coverage and a separate percentage for floor area that members said will push designs upward). Members suggested the code should explicitly preserve long‑standing special setbacks for Alpine Road (75 feet), Portola Road (50 feet) and Skyline Boulevard (200 feet) rather than listing only a single example.

Several commissioners and a public commenter raised preservation concerns at Village Square. Chair Breen said he had been “stunned” by an earlier planning commission comment suggesting redwoods might be removed; resident David Cardinal told the commission rezoning an entire parcel “risks enabling redevelopment that could remove large redwoods” and urged that rezoning be limited to the portion of a parcel intended for development or handled via conditional use permits. Horst reiterated there are no plans or active removals now and said mitigation and tree‑preservation options can be explored if a future project is proposed.

The commission agreed to forward comments to the planning commission and town council recommending general support for the draft ordinance with reservations: ask the planning commission to seek flexibility or reduce the minimum density, clarify that special setbacks remain in force, define floor‑area metrics and require further site‑specific feasibility testing (septic, parking and tree impacts) before project expectations harden. The ASCC closed discussion and moved the matter to the planning commission for formal review as HCD completes its comments.

The next procedural step is for staff to respond to HCD’s first letter and for the planning commission to hold public hearings; ASCC members said they expect to review refined materials and provide further comments at that stage.