• How Do I Make an In-person or Online Appointment?
• How Do I File a Complaint for a Code Violation?
• How Do I Submit a Planning Permit Application?
• How Do I Find Out More About the Planning Permit Process?

• How is the Height Limit Applied on my Property?
• How Do I Add an Accessory Dwelling Unit to My Home?
• How Do I Find My Property Lines?
• How Do I Find Out About an Easement on My Property?
• How Do I Trim or Cut Down a Tree?
• How Do I Trim or Remove a Tree in the Public Right-of-Way or Street?
• How Do I Find Out If My Parcel is Legal?
• How Do I Find the Zoning of My Property?
• How Do I Find the Zoning of My Property If It's Located Within a City?
• How Do I Subdivide My Property?

• How Do I Build a Fence?
• How Do I Build an Accessory Building?
• How Do I Build a Well on My Property?

• How Do I Find Out If My New Business Needs a Use Permit?
• How Do I Start a Home Occupation?
• When is a Use Permit Required for Businesses in Unincorporated San Mateo County?
  Anyone looking to open a business in Unincorporated San Mateo County should visit the Planning & Building Department and find out if their proposed business will require a Use Permit. Some business uses are restricted by the Zoning designations for a particular land or building site. Businesses can be cited for a Use Violation if the appropriate Use Permit has not been obtained. Go to the Planning & Building Division site for contact information and office hours.

• How Do I Apply for a Coastal Development Permit?
• How Do I Perform Vegetation Management for Fire Prevention in the Coastal Zone?

Requirements for off-street automobile parking spaces vary depending on the project location, associated zoning,  and/or if the project is eligible for other parking reductions due to State legislation. 

For County off-street automobile parking please refer first to the applicable zoning district regulations.  If the applicable zoning district does not establish parking requirements, then refer to the Parking section of the Zoning Regulations for off-street parking requirements by project type. 

State and local regulations provide for reduced parking requirements for projects with certain characteristics such as its proximity to a major transit stop, project type (like multifamily affordable housing), approach to reducing vehicle-miles traveled associated with an environmental impact under CEQA, transportation demand management requirements from C/CAG, or EV parking needs. See additional FAQs below and review Public Works’ guidance on traffic impact analysis. Note that relevant projects in the coastal zone must comply with Local Coastal Program Policy 2.52.

The County’s Building Regulations (Title 10 of County Ordinance Code) adopted by reference the 2025 California Building Standards Code (Title 24, Parts 1 through 12), including the California Green Building Standards. The Green Building Standards include EV requirements for both residential and non-residential projects. Applicants should incorporate and identify EV parking space and type (charging capability) into project plans during initial permit application submittals so that they can be reviewed by the appropriate Fire Agency and County Building Division. California Government Code Section 65850.71(d) provides that the local jurisdiction reduce the number of required parking spaces by the amount necessary to accommodate an EV charging station and associated equipment. For questions about specific EV parking requirements, please contact the Building Division at (650) 599-7310 or by email.

Short-term bicycle parking typically serves visitors, couriers, and customers, that typically stay less than two-hours at the location. Long-term bicycle parking serves residents and employees, and should provide protection from weather, convenient access to and from the street without the need to use the stairs, and  use of corridors wide enough to accommodate a bicycle. Bicycle parking requirements depend on the project location, associated zoning, 2025 California Green Building Standards Code (adopted by reference by the County as part of Title 10 Building Regulations), and if the project is subject to the C/CAG Transportation Demand Management Policy. In general, for non-residential projects, the California Green Building Standards Code state that projects should use the stricter standard: the Code or adopted regulations. The Code has minimum requirements for both residential and non-residential projects (see Section 4.106.4.4 Bicycle Parking and Section 5.106.4 Bicycle Parking).

Your project may be eligible for reduced off-street parking requirements. In some zoning districts (like Commercial Mixed Use Districts in North Fair Oaks), alternative parking approaches such as shared parking and off-site parking are acceptable, Applicants should also review existing California statutory provisions, such as the state density bonus law (see the Density Bonus Chapter in the County’s Zoning Regulations), and newer legislation, such as Assembly Bill (AB) 2097 for reduced parking minimum eligibility (see FAQ below).

If your project is subject to the C/CAG Transportation Demand Management Policy, you may be able to reduce required parking per Measure 15. If your project is subject to and has an impact per California Environmental Quality Act (CEQA) Guidelines Section 15064.3, Subdivision (b) Criteria for Analyzing Transportation Impacts, you may be able to reduce parking to address impacts.

For other cases, please visit Off-Street Parking Permit Exception.

AB 2097 (Government Code § 65863.2) eliminates minimum automobile parking requirements for most development within a half mile of a major transit stop. AB 2097 defines “public transit” as a “major transit stop” as that term is defined in Public Resources Code Section 21155. Public Resources Code Section 21155 further references Section 21064.3. Collectively, qualifying “public transit” for purposes of AB 2097 includes a “major transit stop” which is a site containing: (1) an existing rail or bus rapid transit station¹ (e.g., Caltrain, BART), (2) a ferry terminal served by either a bus or rail transit service (e.g., Oyster Point), (3) the intersection of two or more major bus routes with a frequency of service interval of 20 minutes or less during the morning (typically 6:00 – 9:00 a.m.) and afternoon (typically 3:00 – 7:00 p.m.) peak commute periods (e.g., intersection of El Camino Real and East Market Street, due to SamTrans ECR and SamTrans 130, both of which have 15-min headways in peak periods), or (4) a major transit stop identified in the applicable regional transportation plan (e.g., Plan Bay Area-identified stops).

For more information about AB 2097, review the California Department of Housing and Community Development Technical Advisory on the Implementation of AB 2097.  Web mapping tools such as the Caltrans High Quality Transit Stops Online Map, with filter applied under “hqta_type” for major bus, ferry, rail or BART applied, can help with identification of potential stops and qualifying parcels.

If AB 2097 likely applies and you intend to use it to seek a reduction in off-street parking requirements, provide the project planner with:  (1) map with stop location(s) and project location with a straight, direct line measurement in miles and feet from the nearest edge of the parcel containing the project site to the transit stop as pinpointed by a map sourcing data from 511.org (e.g., third party maps such as Google Maps) if it is within a public right-of-way, or to any point on the parcel(s) that make up the property upon which the stop is located. Your map should include the roadway network, parcel lines, APNs of the project site, north arrow, scale, and legend. (2) Transit operator(s) and route number(s) that serve the location(s). (3) Hours of operation(s) and schedule during weekdays (6:00 – 9:00 a.m. and 3:00 to 7:00 p.m.) from the transit operators’ website with a weblink to the original documentation. This documentation will support verification by the project planner, as web tools and data may not be consistent with actual conditions.

In general, please consult the applicable zoning district (see Zoning Regulations) for parking design requirements and the San Mateo County Planning Commission’s adopted standards.  If the applicable zoning district does not establish parking design requirements, then refer to the Parking section of the Zoning Regulations for off-street parking requirements. During project referral and review, the Department of Public Works and the relevant Fire Agency will review access to and from any structures, parking areas, driveways, drive aisles, and more.  Further, parking areas must meet minimum Americans with Disabilities Act requirements to access the building, and designated spaces must also meet minimum requirements. Applicants should review resources available to ensure designs meet minimum requirements, including: the Access Requirements for Building Sites Checklist, San Mateo County Department of Public Works Standard Details Book, California Fire Code, Accessible Parking Spaces | ADA.gov, and local fire district requirements.

In general, please consult the applicable zoning district (see Zoning Regulations) and, if applicable, Site Development design standards for bicycle parking and design requirements.  There are typically two types of bicycle parking required: public and private.

“Public” or “short-term” bicycle parking is typically provided near the entrance of a building and is available to serve visitors for shorter durations of time (about 2 hours or less).  Page 52 (page 172 of 219 of pdf) of the

Unincorporated San Mateo County Active Transportation Plan's Appendix C: Design Toolkit includes short-term bicycle parking design guidance, including spacing and requirements for rack design. Bicycle parking provided in the public right-of-way or along a sidewalk must provide adequate clear width, per Building Regulations.

 “Private” or “long-term” bicycle parking is intended to serve residents or employees that are typically at a location for longer durations of time. Parking is often provided in a more secure location, and may be inaccessible to the public.

Page 53 of the Active Transportation Plan toolkit (page 173 of 219 of pdf) includes long-term bicycle parking design guidance for bicycle lockers. Other resources for reference include:

• Redwood City Bicycle Parking Design Guidelines (June 2024)
• Association of Bicycle and Pedestrian Professionals (APBP) Essential of Bike Parking
• San Francisco’s Zoning Administrator Bulletin No. 9 Bicycle Parking Requirements: Design, Layout, and Calculation

Projects that intend to establish new designations in the County right-of-way will need to work with Public Works and seek approval from the County Board of Supervisors. The County of San Mateo Board of Supervisors has the authority to designate stopping, standing, or parking restrictions or prohibitions on County-owned property and streets and makes the restrictions enforceable by the appropriate law enforcement agency (see Title 7 of the San Mateo County Municipal Code, including Chapter 7.28 Miscellaneous Parking Regulations). The  San Mateo County Department of Public Works manages on-street parking and parking restriction requests, including new or modified curb markings to establish no parking, time-limited parking, loading zones, disabled parking, and passenger loading zones. Visit their webpage to see existing restrictions in effect. If the parking restriction on a County street is due to a review requirement from another agency, such as Fire, the assigned project planner will work with the applicant to determine the appropriate path for consideration of the restriction.

To apply online for a Building Permit, please login or register for a free account at our online Permit Center.

The staff reviews your plans and routes them to several other departments for their review, including:

• Current Planning
• Health
• Building Inspection Section
• Fire
• Public Works
• Public Utilities

Once you have made any required changes and all departments have given their approvals, we will send you a card telling you that you may pay your permit fees and receive your permit.

The fees for a permit, plan check, and other services vary depending upon a number of factors. You may get a current fee schedule and pay your fees at the permit counter.

Different building projects have different requirements (for instance, a single-family home permit requires far more extensive plans, fees, and inspections than a permit to re-roof a single-family home). For questions on requirements, please call the building counter at (650) 599-7310.

When plans are required for a permit, they must be drawn to minimum scale on substantial paper. Please refer to our document Plan Requirements for further information. Your drawings must be legible and must be complete enough to describe accurately how you will accomplish the proposed work.

For minor projects such as most decks, kitchen remodeling, bathroom remodeling, and even some small additions, you do not need an architect. However, if you are unfamiliar with drawing techniques, construction codes, symbols, or terminology, you should consider obtaining the services of a qualified draftsperson. For major projects, we encourage you to consider hiring a licensed architect or engineer.

Permit fees vary depending on the type of permit. A permit technician can provide you with an explanation of the fee schedule and, in many cases, an estimate of the fees for your project.

The length of time it takes to process a permit depends on the type of permit you are applying for and your property's location. If your property is within an area that is subject to certain discretionary planning permits, such as Design Review, Coastal Development, or similar planning permits, your processing time will increase. The volume of permits in process and the complexity of your project can also affect processing time. We review permits on a first-come, first-served basis, but we speed up the process for minor projects, such as those mentioned in Question 2, by reviewing them separately from the more complicated ones.

San Mateo County has a variety of geologic conditions ranging from expansive soils to seismic fault conditions. A geotechnical review can identify potential problems and ensure that you have incorporated proper engineering measures into your project design. In many cases, the State of California has mandated that you make specific measures a part of your design. The purpose of this process is to help you to protect your property, your neighbors, and yourself from the physical and economic injury that some geologic conditions can cause.

Permits do have term limitations. Large projects such as new residences and additions are valid for one year and can be renewed for a second year without additional fees. Projects such as decks, water heaters, electrical services, and similar permits are valid for one year to start construction. In addition to the term limits associated with a permit, you must also obtain a progress inspection at least every 180 calendar days once a project has started. This inspection must demonstrate substantial progress in one or more significant trades. If, for any reason, you are unable to have a valid progress inspection, you must request an extension "prior" to the expiration of your permit. All requests for an extension must be submitted in written form, and why you are requesting the extension must be stated. Failure to obtain an inspection or an extension will result in the expiration of your permit.

The only exception to term limitations is Fire System Permits, which do not expire.

The County Assessor's office is the primary source of information about your property. Ask for a copy of the parcel history for your parcel. This history is typically one or two pages with dates of all building permits and general data about construction. The Assessor's office can be reached at (650) 363-4500.

For more detailed records - particularly for construction since 1982 - you may submit a public records and research request directly to Planning and Building. For more information please visit our Public Records and Research Requests page.

See the San Mateo County Office of Sustainability's Guide for Contractors & Home Owners, pages 5-7.

Second units, also known as “accessory dwelling units,” (or “granny units,” “in-law units,” and various other names) are smaller units built on the same property as, or attached to, an existing primary residence. . . . View More

Noise sources associated with demolition, construction, repair, remodeling or grading of real property can take place between the hours of 7:00 am and 6:00 pm. on weekdays, 9:00 am and 5:00 pm on Saturdays, never on Sundays, Thanksgiving Day or Christmas Day.

Counter Service Appointments
The Planning and Building Counter on the 2^nd Floor is open to the public from 8:00 am - 4:00 pm, Monday - Thursday (closed 12:00 - 1:00 pm for lunch) and closed Friday - Sunday. We strongly encourage you to make an appointment for a virtual or in-person meeting with a Planner or Building Technician through our appointment system. (See instructions for using virtual appointments.) We make every effort to accommodate drop-ins as availability allows, but suggest scheduling an appointment to ensure we can serve you effectively.

Environmental Health
Thursday, 7:00 am - 10:30 am
Call Edgardo Diaz at:
(650) 363-1820, Planning Office
(650) 372-6200, EH Office

View our detailed instructions on how to create an in-person or online appointment.

The Code Enforcement Unit investigates suspected violations. After each investigation in which a code enforcement officer determines that a violation exists, the officer issues a Notice of Code Violation or a Notice and Order to Abate to the person responsible.

What happens depends upon the type of violation.

If an officer finds that someone is violating a zoning regulation, for example, operating a prohibited business at home, the officer may refer the matter to the County Counsels Office, which could file suit against the violator.

If the officer finds that the matter involves a public nuisance, such as an abandoned car or a large amount of refuse collecting in a yard, he will issue an abatement order. The person receiving that order has 10 days in which to correct the situation. If it is not corrected, the County may step in, "for example, by having the car towed or the refuse removed." The property owner is then billed for actual costs plus a 15% administrative fee.

You cannot appeal a notice that you are violating zoning regulations. You can appeal an abatement order by filing a written request for a hearing with the County Officer who ordered the abatement.

The Abandoned Vehicle Hearing Officer hears appeals involving abandoned vehicles.

The Board of Supervisors hears appeals involving nuisances.

Anyone can report what he or she believes to be a code violation. You can report a violation by coming to the DRC and completing a complaint form, by writing a letter to the Code Enforcement Section, or by phoning Code Enforcement, (650) 363-4825, and requesting that a Code Enforcement Officer return your call. The line has an answering machine 24 hours a day.

It's best to provide your contact information when submitting a complaint. This ensures that County staff has the ability to contact you with any questions or updates. Someone may request the complainant's information but must submit, in writing, a valid reason for wanting it. This request must then be approved by San Mateo County Counsel prior to release. When necessary, the County will accept an anonymous complaint.

If the Code Enforcement Unit verifies that there is a violation, the staff will take enforcement action. If they believe the problem to be a disagreement between neighbors, they may refer you to the Community Services Mediation Program, (650) 363-4841.

Call the Code Enforcement staff at (650) 363-4825.