San Mateo County, CA Building Safety: Building Permits (2026)
Key Facts
- Governs
- Unincorporated San Mateo County only
- Exempting authority
- Planning Director, case-by-case
- Exempted from
- Site development permit, not building permit
- Decision
- Documented in writing by Director
- Appeal
- To Planning Commission per § 8.256.130
Summary
In unincorporated San Mateo County, the Planning Director can exempt interior remodels, repairs and minor exterior work from the discretionary site development permit, though a standard building permit is still required.
The Director or designee may except minor activities which otherwise require a site development permit from the requirements of this Chapter when such activities, in the judgment of the Director, are minor in nature and will not have an adverse effect on compliance with design standards or guidelines or zoning regulations applicable to the property or structure in question. Minor projects include interior remodels, repair and maintenance, and minor exterior modifications that comply with the design standards, or other minor exceptions determined at the Director's discretion.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 47).
Full Breakdown
San Mateo County Ordinance Code § 8.308.100 lets the Planning Director except minor activities that would otherwise trigger a site development permit, including interior remodels, repair and maintenance, and minor exterior modifications that meet design standards, from that permit's requirements, provided the work won't harm compliance with design standards or zoning regulations. This applies only in the unincorporated county; it exempts projects from the discretionary design-review permit, not from the standard building permit still required for construction work. Applications for the exception go through the Planning and Building Department with fees set by the Board of Supervisors.
Violations & Fines
Undertaking a project that needs a site development permit without the Director's minor-exception approval, or building without the required building permit, can trigger a stop-work order and code enforcement action.
Frequently Asked Questions
Does an interior remodel need a site development permit in unincorporated San Mateo County?
Do I still need a building permit for an interior remodel?
Sources & Official References
Other rules in San Mateo County
California rules heatmap·Compare San Mateo County to another location·View the California building safety overview
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