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Title 8 — ZONING & DEVELOPMENT CODE

Chapter 8.48 — COSC, COMMUNITY OPEN SPACE CONSERVATION DISTRICT

San Mateo County Zoning Code · 2026-06 edition · updated 2026-07-25 · San Mateo County

8.48.010 Regulations For “COSC” District.

The following regulations shall apply in all “COSC” Districts and shall be subject to all applicable provisions of Article 2 (Development Procedures) and Article 3 (General Development Standards) of Title 8.

(Prior Code § 6225, 6226, 6227, 6228; Ord 2701 – 12/16/80)

8.48.020 Purpose.

The purpose of the “COSC” District is to protect areas designated for general open space in adopted Community Plans by providing for planned low intensity development which preserves, to the greatest degree possible, the visual and open characteristics of the land.

(Prior Code § 6225, 6226, 6227, 6228; Ord 2701 – 12/16/80)

8.48.030 Uses Permitted.

  • (a) The following uses shall be permitted in the Community Open Space Conservation District:
  1. Agricultural Uses and Accessory Structures: On-Site Sales of Agricultural Products, including but not limited to the following:

    • a. Flowering crops

    • b. Vegetable crops

    • c. Truck gardening

    • d. Community gardens

    • e. Christmas tree farms

    1. Public Recreation Facilities, including but not limited to the following uses:

      • a. Parks

      • b. Playfields

      • c. Tot lots

  • (b) The following uses shall be permitted in the Community Open Space Conservation District subject to the securing of a use permit in each case:

    1. Nurseries

    2. Livestock and grazing

    3. Commercial Recreation Facilities, including but not limited to the following uses:

      • a. Keeping of confined animals

      • b. Golf courses

      • c. Driving ranges

      • d. Campgrounds (non-vehicular)

      • e. Swimming pools

      • f. Athletic or sports clubs and facilities

    4. Institutional Facilities, including but not limited to the following:

      • a. Community centers

      • b. Interpretive centers

  1. One single-family residence per parcel less than 40 acres in size, including accessory buildings and uses. Animal fanciers are also allowed in association with a single-family residence, subject to an animal fanciers’ permit. The

Director of Planning and Building may, on a case-by-case basis, exempt accessory buildings and uses and animal fanciers from the use permit requirement.

  1. Division of land, except that no residential uses shall be permitted on a parcel recorded after December 1, 1981.

(Prior Code § 6225, 6226, 6227, 6228; Ord 2701 – 12/16/80)

8.48.040 Development Standards.

  • (a) Minimum building site: 2 acres

  • (b) Maximum height permitted: One-story not to exceed 16 feet in height

  • (c) Maximum lot coverage permitted: 10%

  • (d) Minimum yards required:

    1. Front and rear: 50 feet

    2. Sides: 20 feet each side

  • (e) Signs: Exterior advertising shall be prohibited. One non-illuminated identification sign not to exceed 20 square feet on each face shall be permitted.

  • (f) Design Review: All structures in this district shall be subject to architectural and site review by the Planning Commission as a portion of the use permit process to ensure that the architectural and site design is compatible with its environmental setting. Design guidelines set forth in the Community Design Manual and the Local Coastal Program (for areas in the Coastal Zone) shall be employed by the Planning Commission in the design review process.

(Prior Code § 6225, 6226, 6227, 6228; Ord 2701 – 12/16/80)

(Prior Code § 6227(b); Ord 2774 – 04/06/82)

(Prior Code § 6227(b); Ord 3432 – 11/10/92)

(Prior Code § 6227(b)(3)(a); Ord 4075 – 03/20/02)

(Prior Code § 6227(b)(4)(b); Ord 4844 – 05/04/21)

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Contents — San Mateo County Zoning Code
San Mateo County Zoning Code
  1. Title 8 — ZONING & DEVELOPMENT CODE
    Overview
    1. Article 1 — ZONING DISTRICTS, OVERLAY, AND COMBINING DISTRICTS
    2. Chapter 8.04 — ZONING GENERAL PROVISIONS
    3. Chapter 8.08 — DISTRICTS
    4. Chapter 8.12 — RE, RESIDENTIAL ESTATES
    5. Chapter 8.16 — R1, ONE-FAMILY RESIDENTIAL DISTRICTS
    6. Chapter 8.20 — R1-CCP, COUNTRY CLUB PARK
    7. Chapter 8.24 — R2, TWO-FAMILY RESIDENTIAL DISTRICT
    8. Chapter 8.28 — R3, MULTIPLE-FAMILY RESIDENTIAL DISTRICT
    9. Chapter 8.32 — R3-A, AFFORDABLE HOUSING DISTRICT
    10. Chapter 8.34 — PUD, PLANNED UNIT DEVELOPMENT DISTRICT
    11. Chapter 8.36 — A1, AGRICULTURAL DISTRICT
    12. Chapter 8.40 — A2, EXCLUSIVE AGRICULTURE DISTRICTS
    13. Chapter 8.44 — A3, FLORICULTURAL DISTRICTS
    14. Chapter 8.48 — COSC, COMMUNITY OPEN SPACE CONSERVATION DISTRICT
    15. Chapter 8.52 — EG, EL GRANADA GATEWAY DISTRICT
    16. Chapter 8.56 — P, PARKING DISTRICT
    17. Chapter 8.60 — H1, LIMITED HIGHWAY FRONTAGE DISTRICT
    18. Chapter 8.64 — O, OFFICE DISTRICTS
    19. Chapter 8.68 — C1, NEIGHBORHOOD BUSINESS DISTRICTS
    20. Chapter 8.70 — C1/NFO DISTRICT, NEIGHBORHOOD BUSINESS DISTRICT…
    21. Chapter 8.72 — C1/WMP District (NEIGHBORHOOD COMMERCIAL/WEST M…
    22. Chapter 8.76 — C2, GENERAL COMMERCIAL DISTRICTS
    23. Chapter 8.78 — C2, GENERAL COMMERCIAL DISTRICTS NORTH FAIR OAKS
    24. Chapter 8.82 — CCR, (COASTSIDE COMMERCIAL RECREATION DISTRICT)
    25. Chapter 8.86 — M1 (LIGHT INDUSTRIAL DISTRICTS)
    26. Chapter 8.88 — M1/NFO DISTRICT (MIXED-USE INDUSTRIAL/NORTH FAI…
    27. Chapter 8.90 — M1/EDISON/NFO” DISTRICT (MIXED-USE INDUSTRIAL/E…
    28. Chapter 8.94 — M2, HEAVY INDUSTRIAL DISTRICTS
    29. Chapter 8.98 — W, WATERFRONT DISTRICT
    30. Chapter 8.102 — I/NFO, INSTITUTIONAL/NORTH FAIR OAKS DISTRICT
    31. Chapter 8.106 — PAD DISTRICT, PLANNED AGRICULTURAL DISTRICT
    32. Chapter 8.110 — RH, RESIDENTIAL HILLSIDE DISTRICT
    33. Chapter 8.114 — PC DISTRICT (PLANNED COLMA DISTRICT)
    34. Chapter 8.118 — CMU-1 DISTRICT (COMMERCIAL MIXED USE-1 DISTRIC…
    35. Chapter 8.122 — CMU-2 DISTRICT (COMMERCIAL MIXED USE-2 DISTRIC…
    36. Chapter 8.126 — CMU-3 DISTRICT (COMMERCIAL MIXED USE-3 DISTRIC…
    37. Chapter 8.130 — NMU DISTRICT (NEIGHBORHOOD MIXED-USE DISTRICT,…
    38. Chapter 8.132 — NMU-ECR DISTRICT (NEIGHBORHOOD MIXED USE DISTR…
    39. Chapter 8.134 — RM DISTRICT (RESOURCE MANAGEMENT DISTRICT)
    40. Chapter 8.138 — RM-CZ DISTRICT (RESOURCE MANAGEMENT DISTRICT- …
    41. Chapter 8.142 — TPZ, TIMBERLAND PRESERVE ZONE
    42. Chapter 8.146 — TPZ-CZ, TIMBERLAND PRESERVE ZONE, COASTAL ZONE
    43. Chapter 8.150 — “S” DISTRICTS 1 to 13 (COMBINING DISTRICTS 1-13)
    44. Chapter 8.154 — S17 DISTRICT (COMBINING DISTRICT, MIDCOAST)
    45. Chapter 8.158 — S50 DISTRICT (COMBINING DISTRICT, NORTH FAIR O…
    46. Chapter 8.162 — S71 DISTRICT (COMBINING DISTRICT, DEVONSHIRE)
    47. Chapter 8.166 — S72 DISTRICT (COMBINING DISTRICT, WEST MENLO P…
    48. Chapter 8.170 — S73 DISTRICT (COMBINING DISTRICT, NORTH FAIR O…
    49. Chapter 8.174 — S74 DISTRICT (COMBINING DISTRICT, SELBY NEIGHB…
    50. Chapter 8.178 — S75 DISTRICT (COMBINING DISTRICT, WEEKEND ACRES)
    51. Chapter 8.182 — S81 DISTRICT (COMBINING DISTRICT, SAN MATEO HI…
    52. Chapter 8.186 — S82 DISTRICT (COMBINING DISTRICT, WEST MENLO P…
    53. Chapter 8.190 — S83 DISTRICT (COMBINING DISTRICT, LOS TRANCOS …
    54. Chapter 8.194 — S90 DISTRICT (COMBINING DISTRICT, MENLO OAKS)
    55. Chapter 8.198 — S91 DISTRICT (COMBINING DISTRICT, PALOMAR PARK)
    56. Chapter 8.202 — S92 DISTRICT (COMBINING DISTRICT, WEST MENLO P…
    57. Chapter 8.204 — S93 DISTRICT (COMBINING DISTRICT, NORTH FAIR O…
    58. Chapter 8.212 — S95 DISTRICT (COMBINING DISTRICT, LADERA)
    59. Chapter 8.216 — S100 DISTRICT (COMBINING DISTRICT, MENLO OAKS)
    60. Chapter 8.220 — S101 DISTRICT (COMBINING DISTRICT, PALOMAR PARK)
    61. Chapter 8.224 — S102 DISTRICT (COMBINING DISTRICT, DEVONSHIRE)
    62. Chapter 8.228 — S104 DISTRICT (COMBINING DIESTRICT, LADERA)
    63. Chapter 8.232 — S105 DISTRICT (COMBINING DISTRICT, MIDCOAST)
    64. Chapter 8.236 — S106 DISTRICT (COMBINING DISTRICT, LADERA)
    65. Chapter 8.240 — S108 DISTRICT (COMBINING DISTRICT, LOS TRANCOS…
    66. Chapter 8.244 — S110 DISTRICT (COMBINING DISTRICT, LADERA)
    67. Chapter 8.248 — AO DISTRICT (AIRPORT OVERLAY DISTRICT)
    68. Chapter 8.252 — CD DISTRICT (COASTAL DEVELOPMENT DISTRICT)
    69. Chapter 8.256 — DR DISTRICTS (DESIGN REVIEW DISTRICTS)
    70. Chapter 8.260 — MH DISTRICTS (MOBILE HOME PARKS)
    71. Chapter 8.264 — GH DISTRICT (GEOLOGIC HAZARDS DISTRICT REGULAT…
    72. Chapter 8.272 — E DISTRICT (ENTERTAINMENT OVERLAY DISTRICT)
    73. Chapter 8.276 — APPROVED SS & PUD DISTRICT REGULATIONS (SPECIA…
    74. Chapter 8.280 — USE PERMITS.
    75. Chapter 8.284 — LEGAL LOT REQUIREMENT, ZONING & BUILDING VIOLA…
    76. Chapter 8.288 — MAJOR DEVELOPMENT PRE-APPLICATION PROCEDURES.
    77. Chapter 8.292 — RM DEVELOPMENT REVIEW CRITERIA
    78. Chapter 8.294 — RM-CZ DEVELOPMENT REVIEW CRITERIA
    79. Chapter 8.296 — DEVELOPMENT REVIEW PROCEDURE
    80. Chapter 8.300 — FLOOD HAZARD AREAS
    81. Chapter 8.304 — ARCHITECTURAL SUPERVISION
    82. Chapter 8.308 — NORTH FAIR OAKS DESIGN REVIEW AND SITE DEVELOP…
    83. Chapter 8.312 — ZONING, REZONING, LAND DIVISION, IN THE TIMBER…
    84. Chapter 8.314 — LAND MANAGEMENT PLANNING REQUIREMENTS FOR USES…
    85. Chapter 8.316 — ZONING, REZONING, LAND DIVISION IN THE TIMBERL…
    86. Chapter 8.318 — LAND MANAGEMENT PLANNING REQUIREMENTS FOR USES…
    87. Chapter 8.320 — VARIANCES AND HOME IMPROVEMENT EXCEPTIONS
    88. Chapter 8.324 — ACCESSORY USES PERMITTED IN ANY “R” DISTRICT.
    89. Chapter 8.328 — STANDARDS FOR INDUSTRIAL USES IN THE C-1,C-2,M…
    90. Chapter 8.332 — FENCES, HEDGES, WALLS, HEIGHT & EXCEPTIONS
    91. Chapter 8.336 — HEIGHT: GENERAL PROVISIONS AND EXCEPTIONS.
    92. Chapter 8.340 — YARDS: GENERAL PROVISIONS AND EXCEPTIONS
    93. Chapter 8.344 — OFF-STREET PARKING STANDARDS
    94. Chapter 8.348 — ACCESSORY BUILDINGS
    95. Chapter 8.352 — SPECIAL SETBACK LINES
    96. Chapter 8.356 — HEIGHT OF STRUCTURES AND USES OF AIRSPACE NEAR…
    97. Chapter 8.358 — HEIGHT OF STRUCTURES AND USE AIRSPACE NEAR SAN…
    98. Chapter 8.360 — DEVELOPMENT ON LANDS CONTIGUOUS TO RM, RM-CZ, …
    99. Chapter 8.364 — ROAD IMPROVEMENT REQUIREMENTS IN THE SKYLINE A…
    100. Chapter 8.368 — SHORT-TERM RENTALS (COASTAL ZONE)
    101. Chapter 8.372 — CHILD CARE CENTERS
    102. Chapter 8.376 — WIRELESS TELECOMMUNICATION FACILITIES
    103. Chapter 8.380 — KEEPING OF ANIMALS & DOMESTIC POULTRY IN
    104. Chapter 8.384 — CONFINED ANIMAL REGULATIONS
    105. Chapter 8.388 — ZONING NONCONFORMITIES
    106. Chapter 8.392 — ACCESSORY DWELLING UNITS
    107. Chapter 8.396 — ACCESSORY DWELLING UNITS, COASTAL ZONE
    108. Chapter 8.400 — SIGNIFICANT TREE REGULATIONS
    109. Chapter 8.404 — HERITAGE TREE REGULATIONS
    110. Chapter 8.408 — REGULATION OF TIMBER HARVESTING
    111. Chapter 8.412 — TOPSOIL SITE REGULATIONS
    112. Chapter 8.416 — SURFACE MINING AND RECLAMATION
    113. Chapter 8.420 — QUARRIES
    114. Chapter 8.424 — OIL AND GAS WELL REGULATIONS
    115. Chapter 8.428 — HISTORIC PRESERVATION PERMITS AND PROCEDURES.
    116. Chapter 8.432 — INCLUSIONARY REQUIREMENTS FOR AFFORDABLE HOUSING
    117. Chapter 8.436 — DENSITY BONUS
    118. Chapter 8.440 — ESTABLISHMENT OF FEES
    119. Chapter 8.444 — AMENDMENTS
    120. Chapter 8.448 — FORM OF PETITION, APPLICATIONS, AND APPEALS.
    121. Chapter 8.452 — ENFORCEMENT, LEGAL PROCEDURES, PENALTIES.

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