601–611 Folsom Street

1. Apr 1990

   Drywall ceiling & reinstall surface mounted lights.

   Withdrawn Permit 9007584 $$$ $1,800
2. Oct 1991

   Replace high voltage fire alarm system with low voltage.

   Expired Permit 9119371 $$$ $350,000
3. Mar 1993

   Replacement of generator/construct of 3 walls around generat.

   Expired Permit 9304660 $$$ $890,000
4. Jul 1994

   Replace supply air plenum and fans.

   Expired Permit 9411432 $$$ $200,000
5. Oct 1995

   Replace 2 existing supply air fan.

   Expired Permit 9517770 $$$ $185,000
6. Aug 1996

   Hvac project--install exhaust system, reinforcing wall open'g.

   Complete Permit 9615089 $$$ $300,000
7. Dec 1997

   Add 3 ahus cws & r piping & ductwork toexisting system.

   Expired Permit 9724438 $$$ $250,000
8. Mar 2000

   Battery room, and closing of battery rm @ 2nd floor.

   Complete Permit 9923127 $$$ $375,000
9. Feb 2001

   Install hvac, chilled water piping & new power feeds (1st floor).

   Complete Permit 200102071531 $$$ $159,000
10. Jun 2002

    Furnish and test fire detection system for entire building.

    Expired Permit 200206048146 $$$ $521,250
11. Apr 2003

    Add one cololing tower & piping, contols, location on roof new cooling tower with provide back up for m.

    Expired Permit 200304031344 $$$ $150,000
12. Feb 2004

    Replacement of chillers located in basement/rplmnt of 2 chilled water pumps.

    Complete Permit 200402196744 $$$ $275,000
13. Aug 2004

    Room prep. to accommodate additional one standby generator relocate walls, modify ventitation and.

    Expired Permit 200408030542 $$$ $680,000
14. Oct 2005

    Retro fitting existing building with new fire protection systems. basement to roof with new class ii stand pipe for hose stations. sprinkler per highrise ordinace phase ii-phase i separate permit.

    Complete Permit 200510266577 $$$ $368,175
15. Nov 2006

    Battery room & restroom ada upgrade on 9th floor. hvac upgrade on 8th & 9th floor to accommodate new battery room and telco equipment. two exit ramps (raised floor) from battery room (9th).

    Expired Permit 200611137557 $$$ $700,000
16. Nov 2007

    Repair/replace existing insulation in vertical air supply plenum on all floors of building/ encapsulate insulation with 22gauge sheet metal from basement to 9th floor, install new code compliant access doors for duct work on all floors.

    Complete Permit 200711057341 $$$ $500,000
17. Oct 2009

    Replacement of a supply fan, sq ft-6, to the ninth. floor air handler.

    Complete Permit 200910018107 $$$ $182,125
18. Jan 2013

    Install new roof top air handler and duct work.

    Complete Permit 201301258761 $$$ $750,000
19. Jan 2016

    2nd floor: at&t- install 2 in-row cooling units one is redundant; maher n/a separate permit deferred for 4" sprinkler pipe relocation.

    Complete Permit 201601257847 $$$ $200,000
20. Apr 2018

    9th floor: install a pair of crac units and replace a chiller in the basement. n/a for maher.

    Complete Permit 201804277611 $$$ $500,000
21. Dec 2018

    Install 2 new computer room air handlers on the 3rd fl.

    Complete Permit 201812178497 $$$ $200,000
22. Aug 2021

    Replace 1 water cooled ac unit on the 6th floor with 2 new chilled water ac units on 6th floor. remove 2 existing closed circuit cooling towers on the roof. remove all condenser water piping, supports, and electrical feeders on the roof for the removed cooling towers. we are not moving any existing walls.

    Issued Permit 202108136420 $$$ $250,000
23. Feb 2023

    Install mechanical and electrical infrastructure to support telephone equipment.

    Complete Permit 202302141935 $$$ $500,000
24. Mar 2023

    Reroofing.

    Complete Permit 202303203971 $$$ $1,253,814
25. Aug 2024

    Secure vertically oriented/long alumium panels across all elevations of the building. this is a preventive measure. a full facade study is also planned in august 2024 to observe and meet with city's facade inspection requirement.

    Issued Permit 202407196873 $$$ $845,000

DBI holds 150 permits for this parcel, most of them tenant improvements on individual floors. The timeline shows the 24 largest by stated cost, plus the earliest on file; the DBI query in the sources below returns all 150. 4 of them are nominal $1 street-space or sidewalk permits.

The building is one of AT&T's principal telephone-switching sites in San Francisco. In 2006 a former technician disclosed that Room 641A held equipment splitting AT&T's fibre-optic backbone traffic to the National Security Agency.