Title 8 — ZONING & DEVELOPMENT CODE

Chapter 8.178 — S75 DISTRICT (COMBINING DISTRICT, WEEKEND ACRES)

San Mateo County Zoning Code · 2026-06 edition · ingested 2026-07-06 · San Mateo County

8.178.010 - Regulations For “S-75” Combining District (Weekend Acres).

The following regulations shall apply in the single-family (R-1) residential zoning district with which the “S-75” District is combined.

In the case where a requirement, standard, or provision of this Chapter conflicts with another requirement, standard, or provision in the Zoning Regulations, including this Chapter, the most limiting provision shall take precedence and govern.

8.178.020 - Building Site Width.

The minimum building site width shall be an average of 50 feet .

8.178.030 - Building Site Area.

The minimum building site area shall be 5,000 sq. ft.

8.178.040 - Development Density.

The maximum density of development shall be 8.7 dwelling units/net acre.

8.178.050 - Building Setbacks.

The minimum building setbacks shall be:

Front: 20 feet Sides: 10 feet - When the side property line fronts a public or private street

5 feet - All other cases

Rear:

20 feet

As specified in Board of Supervisors Resolution 50893, adopted October 11, 1988, the Director of Public Works shall require that new development on Bishop Lane maintain a building setback to allow for a 40-foot right-of-way. Therefore, the required building setback for new development on Bishop Lane is 30 feet.

Top of Side Slopes: No construction or creation of any building shall be allowed within the channel of San Francisquito Creek or within 15 feet of the top of the side slopes (as defined in Section 8.04.030(113) of the San Mateo County Zoning Regulations) of said creek. The top of side slope must be delineated by a licensed surveyor (or engineer, architect, or landscape architect) and approved by the Director of Planning and Building or their designee. Construction within the channel and on the banks of San Francisquito Creek, including the construction or creation of any structure, not including a building, including the placing of rubble, dirt or other such materials, is regulated by Board of Supervisors Resolution 26249, adopted April 15, 1969.

8.178.060 - Building Site Coverage Area Ratio.

The maximum building site coverage area ratio shall be .50 (50%) and shall include all: (1) buildings, (2) accessory buildings, and (3) structures such as patios, decks, balconies, porches and other similar uses which are 18 inches or more above the ground, except fences/walls.

8.178.070 - Building Floor Area.

The maximum building floor area shall be established according to the following table:

Building Site Area Maximum Floor Area <5,000 sq. ft. 2,800 sq. ft. 5,000 - 10,000 sq. ft. .26 (building site area - 5,000) + 2,800 sq. ft. >10,000 sq. ft. .13 (building site area - 10,000) + 4,100 sq. ft.

Floor area specifically includes: (1) the area of all stories of all main and accessory buildings on a building site as measured from the outside face of all exterior perimeter walls, (2) the area of all decks, porches, balconies, or other areas covered by a waterproof roof which extends four or more feet from exterior walls, and (3) the area of all garages and carports that exceed 400 sq. ft., but excludes uninhabitable attics and sub-grade basements.

8.178.080 - Building Height.

The maximum building height shall be 28 feet . Building height shall be measured as the vertical distance from any point on the natural or finished grade, whichever is lower , to the topmost point of the building immediately above,

except where a floor of the building is lower than the adjoining exterior natural or finished grade. Building height above any portion of a floor of a building that is lower than the adjoining exterior natural or finished grade, whichever is lower, shall be measured from such lower grade, and not from the floor of the building that is lower than the adjoining exterior natural or finished grade. Chimneys, pipes, mechanical equipment, antennae, and other common facilities may extend beyond the respective maximum height to a maximum of 36 feet as required for safety or efficient operation.

8.178.090 - Daylight Planes.

The daylight planes shall be established by measuring along the side setback lines a vertical distance of 16 feet from the existing grade and then inward at an angle of 45 degrees until a maximum height of 28 feet is reached.

Daylight planes shall not be applicable to the side setback line of the street-facing side of a corner parcel.

Certain architectural features shall be allowed to extend into all yard setback areas according to the provisions of Zoning Regulations Section 8.340.010.

Chimneys, pipes, mechanical equipment, antennae, and other common facilities may extend into the daylight plane up to a maximum of 36 feet as required for safety or efficient operation.

Additionally, architectural features, such as dormers or gables, shall be allowed to extend into the daylight plane of the side setbacks provided that: (1) they measure perpendicularly to the daylight plane no more than 20 feet in continuous or cumulative length on each side, (2) they measure no more than 24 feet in height from the existing grade, (3) the horizontal distance between such features is a minimum of 5 feet, and (4) such features are set back at least 5 feet from both the front and rear building setback lines.

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8.178.100 - Parking.

As specified in Board of Supervisors Resolution 50893, adopted October 11, 1988, new residential development on Bishop Lane shall be required to provide two covered and two uncovered parking spaces on-site.

(Prior code § 6300.4.31 – 6300.4.40 Ord. 4632; 09/11/12 – repeals Urgency Interim Ord 4591; 10/11/12)