1630 California Street

This 40-unit residential condominium project in one of San Francisco's older neighborhoods, replaced a derelict theater that had been long abandoned. To counteract its otherwise stark surroundings, the architect chose to accentuate the vertical nature of this new six-story building by introducing three cylindrical bays that are clad in a narrow 8" copper shingle from Zappone. The curved bays alternate with angular corner window projections clad in steel siding. As the building ages, and the copper oxidizes, the juxtaposition of these two materials changes and harmonizes over time. The narrow shingles, as opposed to the more standard 16" wide type, allow for a naturally curved surface made of segmented shingles which easily accommodate small bends at the joints while remaining otherwise flat.

In addition to solving many technical problems, the choice of copper shingles as siding creates a softer exterior, something the architect sought as both a counter to an otherwise harsher metal exterior and as a reference to the many notable Queen Anne-styled Victorians, which are characterized by elaborate round corner bays, in the nearby Russian Hill neighborhood. Copper also proved to be the best material for flashing around the curved surfaces and around the complex joining of the segmented windows and curved wall surfaces. The metal's natural ductility allowed for the hand-crafted flashings to fit perfectly around the window frames to achieve a watertight condition.

Architectural Category: Exotic or Unusual Applications