San Mateo County, CA Sign Regulations: Window Signs (2026)
Key Facts
- Window sign cap
- 25% of window glass area
- Applies to
- NMU-ECR District, El Camino Real, North Fair Oaks
- Total sign display area
- 0.75 sq ft per ft of frontage
- Freestanding sign height
- 15 feet maximum
- Billboards, off-premises signs
- Prohibited outright
- Exception authority
- Director of Planning and Building
- Appeal path
- Planning Commission
Summary
In the NMU-ECR District along El Camino Real in unincorporated North Fair Oaks, San Mateo County caps window signs at 25 percent of the window's glass area under Zoning Regulations Sec. 8.132.050(6)(e). Window signage is exempt from the parcel's overall sign display cap, but the same subsection bans billboards, off-premises signs, and any flashing, animated or beacon-style sign in this corridor.
c. Maximum Number of Signs. The maximum number of signs allowed on a parcel is one sign per parcel, or one sign per each 200 feet of parcel street frontage, or one sign per use, whichever is greatest. d. Maximum Total Sign Display Area. The maximum total display area for all signs on a parcel is three-quarters square foot per foot of parcel street frontage. e. Maximum Window Sign Area. Signs located within windows and visible to the public shall not exceed 25% of the area of the window within which the sign is located. Window sign area does not count towards Maximum Total Sign Display Area. f. Maximum Sign Height. The maximum height of signs on a parcel is as follows: (1) Attached signs shall not exceed the height of the building or structure to which the sign is attached and shall not extend above the roofline. (2) Freestanding signs shall not exceed fifteen (15) feet.
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
The NMU-ECR (Neighborhood Mixed Use District, El Camino Real) applies only to parcels along the El Camino Real corridor in unincorporated North Fair Oaks, not county-wide and not to Redwood City, Menlo Park or Atherton, each of which runs its own sign code. 050(6) sets the full sign package for this district. Subsection (a) prohibits signs that can be confused with traffic devices, animated or flashing signs, beacon-style intense-light signs, off-premises signs, abandoned signs, and billboards outright. Subsection (c) caps the number of signs at one per parcel, one per 200 feet of street frontage, or one per use, whichever allows the most.
Subsection (d) caps total display area at three-quarters of one square foot per linear foot of parcel street frontage. Subsection (e), the governing provision here, exempts window signs from that total-area cap but limits any sign placed in a window and visible to the public to 25 percent of that window's glass area. Subsection (f) limits attached signs to the building's roofline and freestanding signs to 15 feet, and subsection (g) allows attached signs to project up to 5 feet, with right-of-way projections needing Public Works approval, or Caltrans approval on El Camino Real itself.
Subsection (h) requires sign design to match the building's architecture and materials. 060, with no public hearing required and no fee schedule listed in this chapter.
Violations & Fines
A window display exceeding the 25 percent cap, or any billboard, off-premises, animated, flashing or beacon sign, is barred outright under Section 8.132.050(6)(a) and must be removed or resized before the county issues or renews a sign permit. A business that needs relief from the numeric standards can ask the Director of Planning and Building for a minor design exception under Section 8.132.060; the Director's decision needs no public hearing but can be appealed to the Planning Commission.
Frequently Asked Questions
Does the 25% window sign cap count against my total sign allowance?
Does this window sign rule apply county-wide?
Can I get an exception if my window sign doesn't fit these standards?
Sources & Official References
Other rules in San Mateo County
California rules heatmap·Compare San Mateo County to another location·View the California sign regulations overview
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