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Title 27 — ZONING

Chapter 27.70 — ACCESSORY BUILDINGS AND STRUCTURES IN REQUIRED YARDS

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

27.70.010 ACCESSORY BUILDINGS.

(a) Location of Detached Accessory Buildings. A detached accessory building located within the rear one-third of a parcel is exempt from the requirements for interior side and rear yards, provided such structure is separated from the principal building by an area not less than four (4) feet in width that is open to the sky.

(b) Maximum coverage of required rear yards. Accessory buildings shall not occupy more than 50% of a required rear yard.

(c) Maximum height of accessory structures in required yards. Accessory structures located in required yards pursuant to subsection (a) shall not exceed the following height limits:

R1 Districts Nine (9) feet to the plate line and sixteen (16) feet to the roof peak. All other districts Fifteen (15) feet to the plate line.

(d) Habitable floor limitation. In R1 Districts, accessory structures located in required yards pursuant to subsection (a) shall be limited to one habitable floor on the ground level. Habitable floor for the purposes of this subsection shall mean that served by permanent access and containing windows and/or plumbing fixtures, but shall exclude basements.

(Ord. No. 1992-16 § 17.) Cross References Section 27.70.020(d)(1) Section 27.70.020(e)(1)

27.70.020 STRUCTURES OR BUILDING PROJECTIONS IN REQUIRED YARDS.

(a) R1 Districts. In R1 Districts, Section 27.18.100 shall govern structures or building projections in required yards.

(b) All other districts. For all other districts, the following structures, building projections or features shall be permitted in all yards:

(1) Overhanging eaves and gutters projecting a maximum of three (3) feet or fifty percent (50%) of the required yard width, whichever is less;

  • (2) Awnings, canopies and covered patios;

(3) Greenhouse or oriel bay windows projecting three (3) feet or less into a required yard, provided that the outside face of the projection shall be at least three (3) feet from the property line;

(4) Chimneys projecting two (2) feet or less into a required yard provided that the outside face of the chimney shall be at least three (3) feet from the property line;

(5) Arbors and trellises having a maximum height of eight (8) feet;

(6) Flag poles, garden ornaments and play equipment;

(7) Fences, subject to provisions of Chapter 27.84 of this title;

(8) Basements which are completely below grade;

(9) Steps which are necessary to provide access to the first living level of a permitted building or to a parcel from a street or alley;

(10) Open swimming pools and spas, subject to setbacks from property lines established in Section 23.44.030 of this title.

(c) Front yard projections. For districts other than R1, the following structures or building projections shall be permitted in front yards:

(1) Balconies or decks projecting six (6) feet or less into the required yard;

(2) Porte cochere or similar pedestrian entry feature in multi-family or commercial developments which are less than six hundred (600) square feet in total area and have a width less than twenty (20) percent of the property street frontage.

(d) Rear yard projections. For districts other than R1, the following structures, building projections or features shall be permitted in rear yards:

(1) Accessory structures subject to provisions of Section 27.70.010 of this title;

(2) Open parking spaces;

(3) Balconies or decks projecting six (feet) or less into the required yard;

(e) Interior side yard projections. For districts other than R1, the following structures, building projections or features shall be permitted in interior side yards:

(1) Accessory structures subject to provisions of Section 27.70.010 of this title;

(f) Street side yard projections. For districts other than R1, the following structures, building projections or features shall be permitted in street side yards:

(1) Balconies or decks projecting not more than three (3) feet, provided that the distance between the projection and the street property line shall be at least 7.5 feet.

(2) Porte cochere or similar pedestrian entry feature in multi-family or commercial developments which are less than six hundred (600) square feet in total area and have a width less than twenty (20) percent of the property street frontage.

(f) In all districts, covered pools are not allowed in required yards.

Chapter 27.71 LANDSCAPE FOR PLANNING APPLICATIONS

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Contents — San Mateo Zoning Code
San Mateo Zoning Code
  1. Title 27 — ZONING
    Overview
    1. Chapter 27.02 — GENERAL PROVISIONS
    2. Chapter 27.04 — DEFINITIONS
    3. Chapter 27.06 — ADMINISTRATION
    4. Chapter 27.08 — RULES OF PROCEDURE
    5. Chapter 27.10 — REVIEW PROCEDURE
    6. Chapter 27.12 — FEES
    7. Chapter 27.13 — TRANSPORTATION IMPROVEMENT FEE
    8. Chapter 27.14 — REDEVELOPMENT
    9. Chapter 27.15 — DENSITY BONUS
    10. Chapter 27.16 — RESIDENCE DISTRICTS
    11. Chapter 27.18 — R1 DISTRICTS
    12. Chapter 27.19 — ACCESSORY DWELLING UNITS AND JUNIOR ACCESSORY …
    13. Chapter 27.21 — TWO-UNIT
    14. Chapter 27.24 — R4 DISTRICT—MULTIPLE FAMILY DWELLINGS (HIGH DE…
    15. Chapter 27.26 — R5 DISTRICT—MULTIPLE FAMILY DWELLINGS (HIGH DE…
    16. Chapter 27.27 — RESIDENTIAL
    17. Chapter 27.28 — DOWNTOWN
    18. Chapter 27.29 — RESIDENTIAL OVERLAY DISTRICT—MIXED USE
    19. Chapter 27.30 — C1 DISTRICTS— NEIGHBORHOOD COMMERCIAL
    20. Chapter 27.32 — C2 DISTRICTS—
    21. Chapter 27.34 — C3 DISTRICTS—
    22. Chapter 27.36 — C4 DISTRICTS
    23. Chapter 27.38 — CBD DISTRICTS— CENTRAL BUSINESS DISTRICT
    24. Chapter 27.39 — CBD SUPPORT DISTRICT— CENTRAL BUSINESS DISTRIC…
    25. Chapter 27.40 — BUILDING HEIGHT AND BULK
    26. Chapter 27.44 — E1 DISTRICTS—EXECUTIVE PARK
    27. Chapter 27.48 — E2 DISTRICTS —EXECUTIVE OFFICES
    28. Chapter 27.54 — MANUFACTURING DISTRICTS
    29. Chapter 27.56 — M1 DISTRICTS
    30. Chapter 27.59 — S DISTRICTS
    31. Chapter 27.60 — SPECIAL DISTRICTS
    32. Chapter 27.61 — SC DISTRICTS—SENIOR CITIZEN OVERLAY DISTRICT—S…
    33. Chapter 27.62 — PLANNED DEVELOPMENTS —SPECIAL USE PERMITS
    34. Chapter 27.63 — ADULT ENTERTAINMENT BUSINESSES
    35. Chapter 27.64 — OFF-STREET PARKING AND LOADING
    36. Chapter 27.65 — AMUSEMENT ARCADES AND MACHINES
    37. Chapter 27.66 — HISTORIC PRESERVATION
    38. Chapter 27.67 — OPEN AIR VENDORS
    39. Chapter 27.68 — MAINTENANCE OF PROJECT SITE
    40. Chapter 27.69 — RECYCLING FACILITIES
    41. Chapter 27.70 — ACCESSORY BUILDINGS AND STRUCTURES IN REQUIRED…
    42. Chapter 27.72 — NONCONFORMING BUILDINGS AND USES
    43. Chapter 27.73 — TC DISTRICT—
    44. Chapter 27.74 — SPECIAL USE PERMITS
    45. Chapter 27.75 — MIXED USE CONVENIENCE MARKET/AUTOMOBILE SERVIC…
    46. Chapter 27.76 — PERFORMANCE STANDARDS
    47. Chapter 27.77 — DESIGN REVIEW STANDARDS FOR SERVICE STATIONS
    48. Chapter 27.78 — VARIANCES
    49. Chapter 27.79 — REASONABLE
    50. Chapter 27.80 — AMENDMENTS
    51. Chapter 27.82 — MAPS—BOUNDARY LINES
    52. Chapter 27.83 — SLOPE AND HILLSIDE DEVELOPMENT STANDARDS
    53. Chapter 27.84 — FENCES, TREES AND HEDGES
    54. Chapter 27.85 — DAY CARE CENTERS
    55. Chapter 27.86 — RECYCLING COLLECTION AREAS
    56. Chapter 27.87 — OUTDOOR RESTAURANT SEATING AND MERCHANDISE DIS…
    57. Chapter 27.88 — BAY MEADOWS SPECIFIC PLAN
    58. Chapter 27.90 — TOD DISTRICT— TRANSIT ORIENTED DEVELOPMENT
    59. Chapter 27.92 — HILLSDALE STATION AREA PLAN
    60. Chapter 27.94 — HOUSING

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