Alameda County planners to refine "building" definition after Measure D questions

County planning staff told the Transportation/Planning Committee on Sept. 18 that the zoning code and Measure D constrain how the county counts structure area toward floor‑area ratio limits, and staff will draft a clarifying definition of "building."

Albert Lopez, the county's planning director, told the committee the code definition of a building — "any structure erected for the support, shelter or enclosure of persons, animals, property" — is the basis for deciding whether a covered walkway or similar feature should be counted toward the FAR. Lopez said the East County Area Plan generally sets FAR at 0.01 in Measure D territory and that additions such as agricultural floor‑area bumps are the notable exceptions. "If it requires a building permit and is engineered to support an enclosure," Lopez said, "we would generally consider it to be a building and subject to the floor area ratio." (Albert Lopez, Planning Director.)

Supervisors and members of the public pressed staff on edge cases: unattached, open‑air walkways; semi‑permeable paving; patios with trellises; and whether solar canopies or detached arcades should be treated as floor area. One speaker urged the county to treat such features similarly to solar panels, which the county has interpreted as not counted toward FAR. Rancher Larry Gosling urged outreach to the Ag Advisory Committee to resolve Measure D uncertainty, and resident Harish said an open‑air walkway would be "consistent with these existing interpretations" and supported a clarification that provides certainty while staying aligned with county policy.

Lopez warned of Measure D constraints: "Any zoning code, any ordinance, any policy that the County adopts has to be consistent with Measure D," he said, noting the voters' measure covers large parts of East County. He cited a past case when mausoleums at a cemetery were ultimately determined to be buildings and forced a redesign to meet FAR limits.

The committee directed staff to draft a potential definition or clarifying language for how FAR is applied to open structures and landscaping features and to return with options. The discussion did not change code text at the meeting; it was an informational item with direction to staff, not a final action.

Why it matters: Measure D is a voter‑approved overlay that restricts the county's ability to add permitted uses in large‑parcel agricultural lands. Clarifying the definition of "building" affects what property owners can build without a voter measure and will determine whether certain covered, open‑air features count against scarce FAR allotments in rural East County.

Next steps: Staff will draft proposed language to clarify the building definition and its interaction with Measure D and report back to the committee for further direction.