This 195,000 sf office complex exceeds California energy code requirements by over 30 percent with high performance construction, a green roof and three daylighted atria for the office clusters. L+U assisted the design team with the daylighting design and performance, using physical models to evaluate illumination levels, visual comfort and patterns of sun penetration under various design scenarios. The indirect lighting is photosensor-controlled to respond to exterior illumination levels. Privacy screens in the open office area are custom-designed with light wood finishes and upper panels of translucent glass to allow better diffusion of daylight throughout the office bay.

Heliodon study showing model interior

Located in San Bruno, south of San Francisco, this GAP Corporate Campus building was completed in 1997. The 901 Cherry building consists of three connected office "bays" and attached conference, recreation and cafe spaces which total 195,000 square feet and house 500 employees. In this design, the architects challenged the norm of deep office plates and dark tinted glass which keep the inside and the outside separate. William McDonough describes the design intention: "We believe people want to feel like they've spent the day outdoors in a beautiful place, so we've designed a building full of daylight and fresh air to invigorate the mind, body and spirit."

Exterior view of 901 Cherry showing green roofs, monitors and high clerestories under the curved roof overhang

Each of the three bays of offices and workstations is built around a two-story, landscaped atrium that collects the associated offices and workspaces into an identifiable community with a daylighted center. Popped up through the roof of each atrium is a light monitor with clerestories oriented to the northwest and southeast. A curved reflector redirects daylight into the open office workspace. At nearly 50 feet in height and containing open staircases for easy circulation between the two floors, the center space is kept light with exposed white ceilings and light finishes. Direct sun penetration through these monitors has caused some problems during winter months, as a result of the reduction in the length of the overhangs and the elimination of light shelves originally included in the design. Shades have been installed as an interim solution and a revisiting of the monitor shading design is part of a Phase II project for the Corporate Campus overall.

Large clerestories on the bay ends over the private offices face northeast and southwest, adding significantly to the overall illumination levels. Daylight from these clerestories is reflected up from the office ceilings to the white curved ceiling of the bay. The high performance spectrally selective glazing has a 70% visible transmission for daylight and a 0.42 Shading coefficient for solar gain. In the private offices on the perimeter, the windows are operable and have individually controlled mechanized shades. The overall office lighting by Peerless is indirect and controlled with photosensors to respond to exterior illumination levels. Under-floor air supply allows individual controls and enable night cooling of the building mass to reduce air conditioning energies. The open office system is custom designed with very light wood finishes and upper panels of translucent glass on all privacy screens to allow better diffusion of daylight throughout the office bay. All interior wood and wood veneer in the building was harvested from certified, sustainably managed forests. Materials used throughout the offices are low-toxicity . The undulating roof of the complex is sod, planted with native grasses and wildflowers. The roof absorbs storm water runoff and provides thermal isolation for the interior which is difficult to match with standard insulating products.

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Green Roofs Award of Excellence 2003

Interior of atrium