Cathedral School for Boys, San Francisco
RETROFIT TEAM
ARCHITECT: The Office of Charles F. Bloszies FAIA
GENERAL CONTRACTOR: Truebeck Construction
STRUCTURAL STEEL FRAME, CUSTOM FENCE CONTRACTOR: Westco Iron Works
UNITIZED ALUMINUM CURTAINWALL, FRAMELESS GLASS DOORS CONTRACTOR: RankerAMG
MATERIALS
The multidisciplinary team at The Office of Charles F. Bloszies FAIA conceived the 4,000-square-foot, 2-story addition with a glass and aluminum curtain- wall, light in appearance and weight with its pale green color recalling the nearby verdigris building elements. The team avoided traditional gray or black mullions, which would have presented a dark form when viewed from the cathedral courtyard. From the inside, the addition captures views not seen before of the cathedral and the city beyond.
The unusual choice of a curtainwall system for the exterior reflected the exigencies of the project schedule: It was erected in just over a week, during the pandemic.
The following is a sampling of materials used in the project:
CLEAR INSULATED LOW-E GLASS: Solarban 70 Glass from Vitro Architectural Glass
PVC MEMBRANE ROOF: Sika
ROOF COATING: GacoFlex E5320 from Gaco
CARPET: Urban Retreat from Interface
WOOD CEILING SYSTEM: WOODWORKS Grille from Armstrong World Industries
ACOUSTICAL METAL FLOOR AND ROOF: 3Wx HF-36 Hi Form from ASC Steel Deck
PAINT: Super White from Benjamin Moore
AUTOMATIC WINDOW SHADES: Thermoveil from Mecho
ROOM-DIVIDING WALL: SL70 from NanaWall
LINEAR PENDANTS: Stream Oval from Prudential Lighting
LED Lighting: Aion LED
FIRE-RETRACTABLE OPENING: Won-Door
WOOD-GRAIN LAMINATE CABINETS: Formica
CUSTOM LIVING WALL: Habitat Horticulture
COUNTERTOPS: Caesarstone
THE RETROFIT
An independent elementary school for boys in kindergarten through eighth grade, the Cathedral School for Boys is part of Grace Cathedral Close, which encompasses an entire city block atop Nob Hill with several venerated and beloved historic landmarks. The steel-framed cathedral, encased in concrete, was completed in 1964 and sits amid ancillary buildings that are historic in appearance though constructed during the 20th century. The Cathedral School for Boys is perched at the upper-most corner of the site, adjacent to the cathedral’s apse end, presenting a concrete structure built in the 1960s that takes cues from Le Corbusier’s Chappelle Notre Dame du Haut in Ronchamp, France.
Given the block was already jam-packed with buildings, Bloszies and his design team worked from a master plan that identified a sliver of space between the cathedral and the school, where an outdoor terrace structure with classrooms below had been added in 2009. The site afforded a structurally robust platform, the terrace itself, on which to erect an addition without requiring new foundation work or extensive seismic strengthening of the original building.
Although the new addition site flanked the existing school’s footprint, its design elevated it as a new focal point by renovating existing classrooms on two levels and adding a wide hall connecting the main entrance lobby and addition. The resulting view into the addition from the entrance lobby, with a glimpse beyond to the cathedral wall and its stained-glass windows, essentially creates a new heart for the school.
PHOTOS: Matthew Millman, courtesy The Office of Charles F. Bloszies FAIA, unless otherwise noted