Main menu

Vault (Transformer)


It is our policy to require that all electrical transformer vaults be located on private property. Where exemption is granted and issuance of a Sidewalk Vault Encroachment Permit is authorized by the director of Public Works, the fronting property owner(s) shall comply with all rules, regulations and requirements governing street occupancy including but not limited to Article 15, Section 723.2 of the Public Works Code and DPW Work Order No. 165.553

As required by the Board of Supervisors all Transformer Vault Encroachments are subject to an Annual Assessment (see Fee Schedule). 


Application Guidelines

Public Works may find it necessary to request additional information after initial review of the application. 

  1. An application stating the owner(s), authorized agent (if applicable) and address of the subject property. 

  2. A fee payable by cash, check or VISA/MC only to SF Public Works. Fee Schedule. 

  3. Four (4) sets of Architectural and Structural plan that indicates the property line, sidewalk width and existing sidewalk obstructions such as parking meters, trees, utility poles, etc 

  4. One (1) copy of a PG&E Engineering plan, stamped and approved by PG&E.  

  5. Certificate of Insurance (General Liability) naming the City and County of San Francisco as additionally insured with coverage not less than $1 Million. 

  6. Written confirmation from a licensed design professional that no appropriate space within the owner’s property is available to install the vault and that provides specific and detailed information regarding the need for the vault to be placed within the public right of way and not within private property (NOTE: The plans and letter of confirmation shall be wet stamped and signed by the designer). 

  7. A letter from PG&E authorizing the applicant and/or contractor to excavate and install a vault on PG&E's behalf. 


Design Guidelines 

  1. Transformer Vault shall be installed and located in such a manner that occupies a minimum area of sub-sidewalk space.  

  2. A minimum of four (4) feet from the face of the curb to the outer wall of the vault shall be provided for existing and proposed facilities of the City and public utility companies. (NOTE: Some areas may require a greater clear zone for other municipal structures such as Muni overhead line risers, public pay toilets, etc; NOTE 2: PG&E typically requires a minimum three (3) foot clearance from the building/property line and discourages the placement of transformer vaults within existing/proposed driveways, to accommodate their work space). 

  3. Where applicable, sub-sidewalk space may be used as access only for a vault that extends into a basement within the owner’s property line (NOTE: This may be issued as a Minor Sidewalk Encroachment Permit and also subject to annual assessment fees). 

  4. All lift-out panels shall be constructed with a non-slip/non-skid surface with a minimum coefficient of friction of 0.65 (ASTM-C1028). 

  5. 5. Under no circumstances shall a transformer vault be installed/constructed under the curb, gutter or roadway areas of the public-right-of-way or under the curb return area of the public sidewalk right-of-way. 

  6. Must also meet PG&E Green Book Requirements



vault diagram

Represent dimension between Vault (Transformer) and obstruction including newspaper racks, bike racks, signs, parking meters, hydrants, payphones, lights, SFFD Alarms, etc. 

All Vault (Transformers) must maintain a minimum of:

  • 3’ Clearance from Property/Easement (Subject to PG&E requirements/approval) 

  • 4' from Curb Return 

  • 6' Path of Travel 

  • 5' from Street Furniture (Subject to PG&E requirements/approval) 


Maintenance/Construction Guidelines

  1. All lift-out panels and other trappings shall be installed/constructed and maintained as shown on the plans submitted to and approved by Public Works. 

  2. The Permittee shall make arrangements at their own expense :

    • To provide for the support and protection of facilities belonging to the Department of Public Works, Public Utility Companies, the San Francisco Water Department, the San Francisco Fire Department and other City Departments. 

    • To remove or relocate the location of such facilities and provide access to such facilities for the purpose of constructing, reconstructing, maintaining, operating, or repairing such facilities. 

  3. The Permittee shall obtain all necessary permits and submit all fees to the appropriate City agencies, including but not limited to the Central Permit Bureau and/or Bureau of Street-Use and Mapping of the San Francisco Public Works and the Municipal Transportation Agency (MTA). 

We may find it necessary to request additional information after initial review of the application. 

For More Information

For more information or clarification on any of the permit requirements, please contact us at:

San Francisco Public Works • Bureau of Street-Use & Mapping 
1155 Market Street, 3rd Floor • San Francisco, CA 94103 • Map
Telephone : (415) 554-5810   Fax: (415) 554-6161
Office Hours : 7:30 a.m. - 5:00 p.m.

Monday through Friday, except official holidays

Note: all cash and check transactions must be submitted before 4:00 p.m.