San Mateo County — Signage

Last reviewed: July 3, 2026

Overview

This page summarizes how the San Mateo County Zoning and Development Code regulates signage in the County’s unincorporated areas. It pulls the rules that appear in district design standards and performance standards and explains where numeric limits, prohibited-sign lists, projection rules, design-review triggers, and project-specific (PUD) sign programs live in the Code. For related topics see the County's pages on development standards, design review, parking, overlay districts, historic preservation, nonconforming uses, variances and exceptions and the California Building Standards Code.

Important: these rules apply only to the County’s unincorporated areas (not to incorporated cities inside San Mateo County). Verify parcel-specific application with the County.

Key county code provisions (short primer)

• The County repeats a common set of sign performance and design requirements in multiple district design-standards sections (for example § 8.130.060, § 8.118.060, § 8.122.060, § 8.126.070, § 8.132.060) that together establish the numeric limits, prohibited sign types, projection limits, and approval routes used across many commercial and mixed-use districts. See § 8.130.060 for the most explicit numerical limits and prohibited-sign language.

• Exterior sign lighting and glare control are enforced under general performance/lighting standards (e.g., § 8.114.090).

• Certain industrial or North Fair Oaks (NFO) rules reference signage specifically within the district rules (see § 8.88.050.7).

• Many Planned Unit Development (PUD) ordinances adopt project-specific sign programs (for example PUD-130, PUD-129, PUD-128), requiring a signage program approved by the Director of Planning and Building. See the PUD entries for project-level controls.

District-by-district breakdown

M-1 / North Fair Oaks (Light Industrial / NFO) — where it applies: unincorporated North Fair Oaks industrial areas

• Purpose & typical uses: light industrial, mini-markets (with limits), warehousing, and related employment uses. Signage rules are enforced as part of the M-1 / NFO district standards.
• Key signage rules: signage for certain retail uses (e.g., mini-markets) must comply with the M-1/NFO signage rules and the County Zoning Regulations; exterior lighting (including sign lighting) must confine glare to the premises.
• Approvals: signs that exceed district rules or require projection into the public right-of-way require additional review/approval by the Director of Planning and Building and possibly the Department of Public Works.

High Density Residential (HDR / R-type districts referenced in the Code) — where it applies: certain multi-family residential districts

• Purpose & typical uses: multi-family dwellings and associated residential services. Sign rules in residential districts are intentionally constrained (limited sizes, no internal illumination except by reflected light for some signs). See the allowed sign types and illumination limits under the residential rules.
• Key signage rules: small announcement/bulletin boards and real-estate-for-sale/lease signs are allowed with tight area limits; sign illumination is restricted so glare does not affect adjacent residential uses. Exterior sign lighting must be contained on-site.
• Approvals: director/commission review may be required if signs are nonstandard for the neighborhood. See design exception and variance routes below.

Commercial / Mixed-Use / Retail (design-standard chapters) — where it applies: commercial corridors and mixed-use zones across unincorporated areas

• Typical controlling sections: § 8.118.060, § 8.122.060, § 8.126.070, § 8.130.060, § 8.132.060 — these sections embed consistent sign rules (purpose: protect pedestrian experience, limit visual clutter, and reflect building design).
• Key, recurring standards (common across these sections):
  • Prohibited signs: animated/moving/rotating, flashing, beacons, billboards, off-premises signs, abandoned signs, and signs that interfere with traffic controls or pedestrian safety. § 8.130.060 lists these prohibited types.
  • Maximum number of signs: typically limited by frontage or use (the Code text provides the formula: one per parcel, or one per each 200 feet of street frontage, or one per use — whichever is greatest). § 8.130.060 contains this formula.
  • Maximum total display area: typically three‑quarters (0.75) square foot per linear foot of parcel street frontage for all signs on a parcel. § 8.130.060 contains this limit.
  • Maximum window sign area: window/inside-window signs visible to the public shall not exceed 25% of that window’s area (and typically do not count toward the parcel total). § 8.130.060 states this.
  • Maximum sign height: attached signs cannot exceed the building height or extend above the roofline; freestanding signs are commonly limited to fifteen (15) feet (some older/other excerpts refer to 20 ft in special cases — see Risks & Ambiguities). § 8.130.060 is the primary source for the 15‑ft freestanding limit.
  • Projection limits: attached signs generally may project no more than five (5) feet from the face of the building (some district language lists four (4) feet — see Risks & Ambiguities). Projection into the public right‑of‑way requires approval by the Director of Public Works and for signs on El Camino Real also Caltrans approval. § 8.130.060 and related design standards describe projection and ROW approval.
  • Design requirements: signs should reflect the building’s architectural character, use unifying colors/materials, and avoid obstructing ground-floor transparency; window and awning signs are encouraged over internally lit wall signs in many districts. See the design language in § 8.130.060 and related design sections.
• Approvals & exceptions: minor design exceptions may be granted by the Director of Planning and Building; major exceptions require Planning Commission action (see § 8.118.060 and parallel design-exception sections).

Planned Unit Developments (PUD-128, PUD-129, PUD-130, etc.)

• Purpose & typical uses: site-specific developments approved by ordinance; many include a dedicated "Signage" clause. Examples in the Code require a project sign program or limit the number and lighting of business-identifying signs (e.g., PUD-130 and PUD-129 include one or two permitted business-identifying signs subject to Director approval). See the PUD entries in the Code for the parcel-specific rules.
• Key takeaway: PUDs can override or supplement the standard district rules; always review the PUD language for a parcel.

Decision‑relevant standards (quick table)

Checklist

• Check the zoning district for the parcel and read the district’s design‑standards chapter (e.g., § 8.130.060, § 8.122.060, § 8.118.060).
• Measure parcel street frontage used to calculate allowed sign area and number.
• Confirm whether the parcel is subject to a PUD or other overlay that modifies signage (for example, PUD‑129, PUD‑130, PUD‑128).
• Design signs to avoid prohibited types (no flashing/animated/beacons/billboards) and avoid glare off-site. § 8.130.060 and § 8.114.090 apply.
• If sign projects into public right‑of‑way or is on El Camino Real, secure Public Works (and Caltrans for El Camino Real) approvals.
• If you need an exception from numeric standards, prepare a minor design exception request for the Director or a Use Permit submittal for the Planning Commission (per the applicable design‑standards section).

Risks & Ambiguities

Plain‑English summary

For unincorporated San Mateo County, sign rules live in district design‑standards and performance sections: limit the number and total area of signs by frontage, cap window signage at 25%, usually limit freestanding signs to 15 ft and projections to 4–5 ft, ban animated/beam/billboard/off‑premises signs, and require sign lighting to avoid glare — check the parcel’s district chapter and any PUD for exact, parcel‑specific rules before designing signage. Verify with the County for ROW encroachments and any project exceptions.

Source References

• San Mateo County Zoning & Development Code — design standards and signs (referenced provisions include § 8.130.060)
• Design exception and major/minor exception procedures (§ 8.118.060)
• General performance and exterior lighting standards (§ 8.114.090)
• North Fair Oaks / M‑1 signage reference (§ 8.88.050.7)
• Related district design‑standards with signage text (§ 8.122.060, § 8.126.070, § 8.132.060)
• Example PUD sign provisions: PUD‑130 (Ordinance No. 04251), PUD‑129, PUD‑128 — project sign programs and director approval language (see the PUD entries).

Retrieved passages

• San Mateo County Zoning Code (section may) High relevance show source text
• San Mateo County Zoning Code (Chapter 8.280) High relevance show source text
• San Mateo County Zoning Code High relevance show source text
• San Mateo County Zoning Code (section may) High relevance show source text
• San Mateo County Zoning Code (section may) High relevance show source text
• San Mateo County Zoning Code (Title 8) High relevance show source text
• San Mateo County Zoning Code (Chapter 8.436) Medium relevance show source text

Cited sections

• San Mateo County Zoning & Development Code — design standards and signs (referenced provisions include **§ 8.130.060**) (§ 8.130.060)
• Design exception and major/minor exception procedures (**§ 8.118.060**) (§ 8.118.060)
• General performance and exterior lighting standards (**§ 8.114.090**) (§ 8.114.090)
• North Fair Oaks / M‑1 signage reference (**§ 8.88.050.7**) (§ 8.88.050.7)
• Related district design‑standards with signage text (**§ 8.122.060**, **§ 8.126.070**, **§ 8.132.060**) (§ 8.122.060)
• Example PUD sign provisions: **PUD‑130 (Ordinance No. 04251)**, **PUD‑129**, **PUD‑128** — project sign programs and director approval language (see the PUD entries).
• SanMateoCounty_ZoningCode.md

• Official San Mateo County code library