Great Glazing: San Francisco Public Utilities Commission Headquarters
The basics: By considering its impact on the environment and human performance, architects of the new San Francisco Public Utilities Commission headquarters held sustainability and the federal employees who would occupy the building as key considerations during the entire design process. SFPUC, or 525 Golden Gate, features a sophisticated glass and concrete building envelope that is expected to earn Leadership in Energy and Environmental Design Platinum certification and creates a healthy and comfortable work environment.
Describing the building's materials, all used intentionally for a daylight harvesting system, Jeff Rosenburg, project manager for Benson Industries says, “The light shelf at the transom reflects light up to the ceiling, which reduces electricity for lighting and increases daylighting. The top lite brings light into the building, and the bottom lites are all shaded because of the sunshades and solar-control frit patterns designed to keep the heat gain down without dramatically reducing visibility.”
The players: Architect, Michael Rossetto, KMD Architects; general contractor, Webcor Builders; light shelves/sunshades manufacturer and exterior glazing contractor, Benson Industries; glass fabricator and interior glazing supplier, Hartung Glass Industries; glass manufacturer, PPG Industries; interior glazing contractor, Progress Glass Co.; fire-rated glass and framing supplier, Safti First
The glass and systems: For 525 Golden Gate, open office design combines with light shelves, light-reflective concrete walls, manually operated windows and automated shades that are tied to the trajectory of the sun to maximize daylighting and occupant comfort.
The vision insulating glass units were fabricated with 6 millimeter PPG Solarban 70 XL on the No. 2 surface, 12 mm argon-filled airspace and 6 mm PPG Starphire. The solar control units used on the south elevation were comprised of 6 mm PPG Solarban 70 XL on the No. 2 surface, 12 mm argon-filled airspace, 6 mm Starphire, and a ceramic frit pattern on the No. 3 surface, to increase daylight harvesting, penetrating the light deep into the building’s interior. Inside 525 Golden Gate are Total Vision doors and partitions complete with Impressions decorative privacy ceramic frit fabricated by Hartung.
Among the building’s most striking visual features, as well as an integral part of the building’s energy efficiency, is a transparent stairwell. The fully transparent, interior, two-hour fire-rated glass stairwell enclosure from Safti First spans 14 floors and allows daylight in through the building’s all-glass exterior to further penetrate the interior, illuminating the space with natural light and eliminating the use of electricity. If artificial light is needed, the glass staircase allows shared artificial lighting between spaces, minimizing the electricity load.