Uni-Systems Engineering, Inc.


Completed 2012

Location: Golden Gate Park; San Francisco, California

Scope of Work: Design, Supply, Installation


Architect: Renzo Piano

Structural Engineer: Walter P Moore

California Academy

of Sciences

Retractable Roof

The California Academy of Sciences is a sustainable building located in Golden Gate Park. Its green roof has rolling hills covered with 1.7 million native plants that help keep the building interior cool. A polycarbonate retractable roof nestled among the rolling hills allows light into the piazza below while protecting the space from rain and cold. In favorable weather conditions, the retractable roof provides a 42 by 30-foot opening, turning the piazza into an outdoor area.

The staff of Uni-Systems Engineering designed, supplied, and installed the structure and electro-mechanical drive system for the California Academy of Sciences retractable roof. The new weather-tight panels, which replaced an existing fabric shade, allow the academy to offer programs and house exhibits in the piazza atrium, making it a more usable space that fits better with with the green building design aesthetic.

The roof has two polycarbonate panels that slide along the eight supporting arches and meet in the middle when closed. The panels are driven approximately 6 feet per minute by four 1-hp belt drives, moving between the open and closed positions in approximately 2 minutes, 45 seconds. The fully automatic roof operating system is linked into the building-wide control system with an iPad interface.