Crews from New York City-based Evergreene Architectural Arts applied a protective film to the painted surfaces and remotely monitored the temperature and humidity of the wall cavity behind the murals during shotcrete operations and curing.

The building will have all new mechanical, electrical, plumbing, life-safety and security systems. One hiccup was that the existing three-boiler heating system had to stay operational during the project—and while a new hydronic system went in—because it also served the twin opera house. The work-around was to do the restoration in stages, says Jones.

Keeping Up Appearances

Pioneer Roofing crews replaced lead-coated copper roofing tiles with look-alike zinc panels that will still match the twin building next door. The time-consuming process required 20 steps for each panel.

The old panels were attached to the concrete roof deck using redwood batten supports. However, the new zinc panel system uses an engineered aluminum clip system to support the zinc panels over a waterproof underlayment and drainage layer.

To marry the zinc roof system with the skylights, while preserving the historic appearance of the roof and keeping the transition water-tight, crews soldered custom-formed zinc flashing on the majority of the roof.

The city's project architect, Andy Maloney, "made every effort to reuse rather than replace historic elements from marble bases to wood paneling," Lamont says.

For example, workers removed more than 200 oak doors and dozens of cabinets, which were refinished with new hardware and put back in place. Any new doors were built to match the old ones.

Due to the reuse of materials and new energy-efficient mechanical upgrades, Lamont says the project may qualify for LEED Gold certification.

Work also had to be coordinated with the local Webcor Builders, the contractor selected for the $18-million fourth-floor tenant improvement project, funded by the San Francisco Opera Association. The Pankow team performed the seismic upgrade, installed building systems and prepared the fourth floor shell. Work was carefully coordinated where structural and rough-in work had to be performed prior to the turnover to Webcor.

The Webcor fit-out includes a 300-seat theater and an education and media facility. Completion of that piece is set for early 2016.