Frequently Asked Questions

1) How do I apply online for a Building Permit?

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

Only over-the-counter Building Permits are offered online:

  • Electrical service
  • Gas line
  • HVAC
  • Photovoltaic
  • Reroof
  • Sewer line
  • Siding or stucco
  • Solar pool heating
  • Solar water heating
  • Water heater
  • Water line
  • Windows or doors (size for size)

Please note that some permits may require additional review by the Planning Department prior to issuance.

2) What happens after I apply?

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

  • Current Plannning
  • 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.

3) What fees must I pay?

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.

4) 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.

5) What do I need to submit to get a building permit?

Different building projects have different requirements (for instance, a permit to build a single-family home requires far more extensive plans, fees, and inspections than a permit to re-roof a single-family home). The County has informational pamphlets detailing the requirements for virtually every kind of building project. The best way for you to answer this question is to review the pamphlet for the particular project you have in mind. If that doesn't do it, call or ask the Building Inspection staff.

6) What are the requirements for plans? Must I have an architect prepare my plans?

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.

7) How much does a building permit cost?

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.

8) Why does it take so long to issue my permit?

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.

9) Why does my project require geotechnical review?

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.

10) How long is my building permit valid for?

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 deck, water heaters, electrical services and similar permits are valid for 180 days. In addition to the term limits associated with a permit, you must also obtain a progress inspection at least every 180 calendar days. This inspection must be able to demonstrate substantial progress in one or more of the major 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 extension must be submitted in written form and state the reason why you are requesting the extension. Failure to obtain an inspection or an extension will result in the expiration of your permit.

For further information regarding permit term limits or expirations, please request copies of the appropriate San Mateo County Ordinance Code Sections.

11) How do I get copies of building records for my property?

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 request a research of Building Inspection files from the Building Inspection Section. Please download and complete the Application for Building Permit Research form. Note that there is a fee associated with this work. Also, from the Development Review Center (DRC), you can obtain information about any Planning permit files on your property. Often these files are lengthy and you may not want to pay to have the whole file reproduced. We recommend that you call the Current Planning Section desk (650/363-1825) to find out if there are any records on your property; if so, then arrange a time to come to the office and view the files.

12) Where can I find a list of approved hauling vendors that can meet the requirements for the CalGreen Building Code requirements of recycling demolition debris?

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

13) How do I add a second unit to my home?

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 »

14)  What is the County’s Construction Noise Ordinance?

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


15) What are your office hours?

Development Review Center
Monday - Friday

Planning Counter
7:30 am - 5:00 pm - call (650) 363-1825

Building Counter
7:30 am - 5:00 pm - call (650) 599-7311
For 24-Hour Automated Inspection Scheduling System call (650) 295-3650

Public Works Counter
7:30 am - 5:00 pm - call (650) 363-4161

Environmental Health
Thursday and Friday, 7:00 am - 10:30 am
Call Edgardo Diaz at:
Tel: (650) 363-1820, Planning Office
Tel: (650) 372-6202, EH Office


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