The project to expand the Cathedral School’s existing facilities calls for a two-story addition on top of an existing concrete structure: a historically and structurally sensitive intervention in the complex urban fabric of the landmarked Cathedral Close. The new construction, comprising two floors of open common spaces enclosed by a glass and aluminum curtain wall, with a play yard on the roof, is nestled between the neo-Gothic Grace Cathedral and Choir House (1910-64) and the original modernist Cathedral School building (1965-66), altered in the years since to meet the changing needs of the school as it grew (1995-96, 2008-09).
The new design includes renovation of the existing classrooms, which serves as an opportunity to re-orient the school’s floor plan. The project provides a new primary axis of circulation and sight leading from the main entrance on Sacramento Street to the new heart of the school: the new flexible space used for co-teaching, presentations, or events depending on the users’ needs at the time. On the floor below, another open space is likewise designed as a learning space that accommodates a variety of ad-hoc activities; a folding glass partition divides the space to provide a discrete classroom-sized zone while maintaining the visual continuity of the room. The tall windows of the curtain wall allow for astonishing views of the Cathedral’s façade and stained glass windows just a few yards away, and let the maximum amount of daylight illuminate the addition; operable windows at either end allow for natural ventilation.
The new structure rests on an existing building, requiring that the addition be as lightweight as possible: the slender steel structural supports allow for a light visual presence as well as a feasible design. The glass façade reinforces this lightness; the spandrels are clad with terra cotta, a traditional building material chosen for visual and material harmony with the existing Cathedral and school buildings. Prefabricated components such as the curtain wall, constructed off-site in large panels and hoisted into place in series, allow for an accelerated construction schedule that accommodates the unique timing constraints of the school year.