This page will provide you with a basic understanding of the minimum plan requirements for San Mateo County. Since projects can vary widely, your project may include all or part of these requirements. Please refer to the specific building permit for kitchen or bath remodels, skylights, decks and similar projects.

Requirement for Erosion Control and/or Tree Protection Pre-Site Inspection


Due to state stormwater pollution prevention requirements and recent instances of tree damage and unauthorized tree removal, we have instituted an Erosion Control and/or Tree Protection Pre-Site Inspection Requirement for construction or demolition on specific site types.

New Local Energy Code Requirements

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On February 25, 2020, the County of San Mateo adopted local amendments to the State Building Code Title 24 (Energy Code, Part 6 and Green Building Code, Part 11) requiring all-electric buildings, solar installation for multifamily and commercial buildings, and increased levels of electric vehicle charging infrastructure for all building types. This ordinance only applies to newly constructed buildings from the ground up and does not apply to additions or remodels. 

Water Efficient Landscape Ordinance (WELO)

Picture of water efficient landscape

On July 15, 2015, California approved revisions to the Model Water Efficient Landscape Ordinance (MWELO), which promotes efficient water use in new and retrofitted landscapes.

Requirements for Application Submittal

Building permit applications must be submitted online.

  1. Complete sets of plans in PDF format shall be submitted online when applying for a building permit.
  2. Plans shall be drawn to a minimum scale as noted below and reproduced clearly for required copies. Plans may be submitted on paper as small as 8—1/2" x 11" in blueprint form. No originals or reductions will be accepted.
  3. A complete set of plans shall include the following minimum requirements:

(a)​ Plot Plan (minimum scale 1/16" = 1'0")

  • Must be a topographic survey, stamped and signed by a licensed surveyor. This is a requirement for all new construction or major additions.
  • Owner's name and address (other than the job site).
  • Address of job site, including subdivision name, where applicable.
  • Assessor's parcel number.
  • Dimensions of the property.
  • Size of structures (existing and proposed) and distance to property lines.
  • All paved areas (existing and proposed).
  • Utility connections; if applicable, show the proposed location of the septic tank, diversion valve, and drain fields.
  • Drainage of surface water.
  • North arrow and scale used (with bar scale).
  • Driveway -- show street elevation and garage floor slab elevation.
  • Show contours if the slope is more than 10%.
  • Easements.
  • Trees.

(b) Foundation Plan (minimum scale 1/8" = 1'0")

  • Address of job site.
  • Dimension, size, spacing, extent, and location of all foundations, piers, retaining walls, etc.
  • Floor slabs, including reinforcing and vapor barrier.
  • Typical details, as required.
  • If pier and grade beams are used, submit engineering calculations.
  • Specify the source of design criteria.

(c) Floor Plan (minimum/maximum scale 1/4" = 1'0")

  • Address of job site.
  • Size, location, and identification of all partitions, doors, windows, cabinets, and rooms.
  • Size, spacing, and direction of overhead framing, including roof framing.
  • Lighting and electrical.
  • Plumbing.
  • Heating.

(d) Complete Exterior Elevations and Complete Interior Cross Section Elevations (minimum scale 1/8" - 1'0")

  • Address of job site.
  • Finishes of walls and roof.
  • Windows and doors.
  • Dimensions of the property.
  • Grade at the structure.
  • Floor and ceiling elevations from grade.
  • Identify the elevations.

(e) Details

  • Building section (minimum scale 1/8" = 1'0"). Show all structural elements.
  • Identify the insulation to be used.
  • Stairs, fireplace, decks, railings, etc. (minimum scale 3/4" = 1'0")
  • Curb cut and driveway profile (minimum scale 1/4" = 1'0")
  • Retaining walls. If over 3'0", submit engineering calculations.

(f) Engineering Geology - investigation reports may be required. These reports are retained in the Public Works Geotechnical Section.

(g) Sewer and Water - verification (from districts) is required before permit issuance.

(h) Fire Suppression - details shall be included in the plot plan.

(i) Architect/Engineer(s) Name and License (Calif.) - must be displayed on all design plan sheets and signed.

(j) Energy Calculations - shall be included in the submittal of the plans.

(k) ADA Access Requirements - where applicable.

(l) Fire Sprinkler Permits - if required, a fire sprinkler permit must be issued with or before issuing a building permit.

(m) Erosion and Sediment Control Plan 

Workers Compensation Requirements

As mandated by the Labor Code, Section 3800, contractors or owners/builders applying for permits must provide proof of Workers' Compensation each time a permit is applied for.

An exemption form may be signed instead of providing workers' compensation proof. Notice To Owner/Builders: If you are claiming an exemption from Workers' Compensation and hire a licensed contractor to perform any part of your project (e.g., framing, plumbing, electrical, etc.), you must provide the Building Inspection office with the name, license number and mailing address of the contractor. Please note that this exemption is signed under penalty of perjury.

Worker Compensation must be provided for all persons, including friends, relatives (adult children, cousins, aunts, uncles, etc.), or any other person assisting or working on the project, regardless of whether they are being paid or compensated for such services.

If it is discovered during the life of a permit that persons subject to this regulation are working on the project without the required coverage, a Stop Work Notice will be issued, and notification to the proper authorities will be made. No further inspections on the project will be conducted until the matter has been fully resolved.

Survey of Building Site and Location of Structure Required Prior to Issuance of Building Permit

As part of the inspection process, inspectors are required to verify that proper setbacks have been maintained. The construction of any new building, additions to existing buildings, alterations and remodels which exceed 50% of the valuation of the existing structure (whether or not additional square footage or expansion is involved), accessory structures, decks, swimming pools, pool houses, cabanas, detached garages, barns, stables, retaining walls, water tanks, and similar projects will require a survey.

The use of existing fences or structures is not acceptable for verifying setbacks. Fences, in particular, are unreliable. They are often built or rebuilt without regard to existing property lines. Even structures, such as residences, which have existed for many years, have been found to be located incorrectly.

Although recorded surveys are required in some instances, a boundary survey is acceptable in most cases. Before requesting your surveyor to provide a survey, you should advise the surveyor to contact the Building Inspection Section to determine the required survey type.

Additional Resources