Potrero Branch Facilities Survey

Image of Potrero Branch Library BACKGROUND Year Built: 1951 Architect: Pollack & Pope Seismic Hazard Rating 3 Number of Stories Two w/basement Type: Modern Address: 1616 20th Street Gross Sq. Ft.: 4,391


The recommended modernization plan is to renovate and expand vertically the existing building while reducing the risk associated with a major earthquake. The structural components of the building will be retrofitted to better withstand a major earthquake. Additional concrete columns, beams, heavy timber framing members, and metal connectors are needed to strengthen the building. Expansion options may include removing the roof and adding a floor. Existing stairways, restrooms, staff room, electrical room, mechanical room will be modified or relocated to conform to accessibility requirements, life safety related code requirements and owner improvements.

The basement level is built of concrete box frame while the upper two stories are concrete and wood construction. The community rooms and restrooms on the second floor are ADA inaccessible. The partial second floor is built half a story above the roof of the lower floor. This provides for the opportunity to expand the buildng without increasing the number of stories or blocking existing views.

New or alteration construction will meet State (Title 24) and Federal (Americans with Disabilities Act) guidelines. These guidelines detail minimum requirements and standards for improvements and the corresponding physical dimensions of construction work. The scope of disabled access work anticipated includes: the addition of an elevator; reconfiguring existing restrooms and adding new restrooms; new fire stair; modification of counters, bookshelves and table spacing at the reading room areas; and modification of doors and stairways. Application of the California Accessibility Code and conformance with the latest life safety related code requirements will include: new elevator, and elevator machine room; providing new accessible restrooms, and wider library aisles.

Building code impacts involve the updating of the heating, ventilating, plumbing, fire protection, electrical and other building control system to bring it up to code requirements for life safety.

Current law requires removal of asbestos-containing materials (ACMs), including plasterboard walls, floor tiles, and roofing related to the anticipated construction activities associated with seismic retrofit and disabled access construction work. The removal of ACMs will require relocation of the building occupants because floor areas will be affected and there is significant health risks of exposure to airborne particulars associated with the removal of ACMs. Lead that is impacted shall also be abated.

The recommended modernization plan will involve an expansion, possibly of the second story over the reading room at the north end of the building. The interior of the building will be completely remodeled, and office space will be reconfigured to make more efficient use of the space. The interior remodel and seismic work would trigger conformance work on the American with Disabilities Act (ADA). The modernization work will reduce the public area on the first floor of the library, but would recover that loss by expanding. The existing library has no room to expand horizontally. Therefore, expanding the second story maybe the most cost effective solution to make the facility fully accessible.

The expansion space will accommodate an elevator, create additional space for collections, programs, services, reading area, increase staff work area and add restrooms to 1st floor. The elevator will be accessible from inside the building and during closed hours, this will require a secure lobby area be developed.

Improvements include replacing the flooring, adding data/electrical outlets, and update of the meeting room. Work includes remodeling the existing staff lounge, restrooms, and storage. Also included is window replacement, and new lighting.



  1. The existing wood structure over a box-frame concrete foundation provides for a less than ideal construction for library use.
  2. Although there are many structural weaknesses, there are also many opportunities for seismic upgrade. Special attention should be placed on the concentrated loads placed upon the structure by a new architectural layout.
  3. All point of connection must be evaluated and strengthened as required to resist lateral forces.

Non-Structural Deficiencies

  1. Acoustic tile ceiling finishes could potentially become falling hazards.
  2. Any high windows could potentially become a falling glass hazard.


  1. Reconstruct second story roof and first story roof diaphragms.
  2. Add continuous shear walls from basement to roof.
  3. Add concrete foundations to support new shear walls and other structural elements.
  4. Add shotcrete to strengthen basement foundation.
  5. Add collector beams, and steel moment frames to transfer loads between perimeter walls and interior load bearing walls.
  6. Anchor or otherwise seismically brace all ceiling finishes.
  7. High windows should be replaced with tempered glass or other type of safety glass.


  1. Handicap parking and curb cut are needed in front of the building.
  2. The entire second floor, which holds the public restrooms and the meeting room, is inaccessible.
  3. The existing layout does not allow access into some areas.
  4. Work areas, staff lounge, and other public amenities are not accessible.


  1. Provide accessible parking in front of the library.
  2. Add an elevator to reach all building levels including the basement.
  3. Reconfigure the existing layout to make a more efficient use of space.
  4. Make all work areas and public areas accessible.


  1. The exiting HVAC equipment is in need of replacement. It is anticipated that the proposed renovation will necessitate replacement of all mechanical equipment, and air distribution systems and upgrade to accommodate new space.


  1. Replace all mechanical equipment and distribution system with an updated energy-efficient system.


  1. The main electrical service panel is in poor condition. It is anticipated that the proposed renovation will necessitate replacement of all electrical equipment and the power distribution system.
  2. The building lacks adequate telecommunication and data lines for a flexible layout.


  1. Replace all electrical equipment and the power distribution system with a system of sufficient capacity for the proposed expansion.
  2. Provide telecommunication and data line panel and distribution system.


  1. It is anticipated that the proposed renovation work will necessitate the replacement of all electrical life/safety equipment such emergency lighting, exit signs, fire alarms, and smoke detectors.
  2. The building lacks adequate number of fire extinguishers.
  3. The building needs security lighting, and security grilles.


  1. Replace or add life safety equipment as required.
  2. Add fire extinguishers as required.
  3. Provide new security lighting, and security grilles in the existing design.


  1. Asbestos Containing Materials (ACM’s) are identified throughout the building.


  1. Abate asbestos if found in the domestic hot water piping and fitting insulation, aircell insulation on ducts, and HVAC duct joint tape.
  2. Where impacted by construction, abate asbestos in plaster walls and ceilings, caulking/glazing putty on windows, exhaust flue, vinyl sheet/tile floor and mastic, stucco walls, and built up roof.
  3. Lead that is impacted by construction shall also be abated.


  1. Interior finishes need refurbishment.
  2. The current meeting room lacks multi-purpose multi-media capability.
  3. Study rooms are not provided.


  1. Replace all interior finishes.
  2. Expand the use of the existing meeting room to include a amenities for multi-media\ multi-purpose activities.
  3. Provide study room(s).
  4. Replace existing windows with energy efficient operable windows.


  1. Existing trees need maintenance.
  2. Existing plantings in front of the building need to be refurbished and reconfigured to increase visibility.


  1. Prune trees in front of the building.
  2. Restore planting areas in front of the building after construction.
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