Agoura Hills, California
Agoura Hills, California, is an affluent bedroom community 30 miles northwest of central Los Angeles, marked by lush valleys and broad canyons. But its building stock is less picturesque: along U.S. Route 101, which runs through this small city of about 20,000, drivers are more likely to see banal red-clay-tile-roofed strip malls and gas stations than anything architecturally attractive or intriguing. So the new Conrad N. Hilton Foundation Headquarters, by ZGF Architects' Los Angeles office, is a welcome change of pace. The 22,240-square-foot, $24 million building is a simple rectangular volume clad in strips of auburn, burnt-orange, and deep-yellow split-face sandstone evoking the area's vivid landscapes. The Hilton Foundation, a 69-year-old nonprofit organization, has made its mission “improving the lives of disadvantaged and vulnerable people throughout the world.” It didn't just want a beautiful new office, but one that reflects the foundation's altruistic goals and acts as a model of sustainable design for other organizations across the globe.
The finely detailed, LEED Platinum–certified headquarters, designed for net-zero energy consumption, is the first of four two-story office buildings planned for the 67-acre site. The long, narrow rectangular shape allows daylight into and views out from most of its interior spaces, which include an airy entry, offices (along the center's perimeter), three conference rooms, and central cubicle workspaces on both levels. Among its many green features—a solar thermal-heating system, water-cooled chilling, a planted roof—the building employs a passive-downdraft HVAC system, which provides ventilation and cooling for the 49 occupants. The system comprises 17 downdraft shafts or “chimneys” that punctuate the building's perimeter at regular intervals. Air travels down these shafts, entering the floors of the second and ground levels. “The passive-downdraft system takes advantage of Agoura Hills' moderate weather,” explains Andrew Corney, vice president at environmental design consultancy WSP Built Ecology. “If you have a good ventilation system, you really don't need to put much energy into it.”
As in a Swiss watch, these mechanical systems are concealed behind carefully selected finishes. In the lobby, glass balustrades, alabaster-hued marble flooring, and FSC-certified European ash veneer on the walls create a bright, serene atmosphere. Large windows in offices and conference rooms help bring ample daylight into the space, and clerestory windows above offices allow sunlight to filter into central circulation areas. On a recent visit, workspaces on both levels of the two-story building were brightly, naturally illuminated, despite a predawn fog outside that obscured most direct sun. “During the day, many offices don't use the overhead lighting at all,” says Katherine Miller, the foundation's facilities manager. Absent, then, is the faint buzz of fluorescent fixtures or the whir of overworked mechanical systems. Instead, walking around the foundation's new home instills a distinct sense of calm.
In addition to the abundance of light and air inside the building, the relationship between the foundation's interior and exterior spaces contributes to that tranquility: on the first floor, a large conference room opens up to a terrace. Employees are encouraged to take their lunch breaks or gather for informal meetings outside, and the Santa Monica Mountains to the south, Palo Comado Canyon to the northeast, and nearby Ladyface Mountain provide a remarkable backdrop. Public areas, offices, and open workspaces on both levels look out on the surrounding ranges, free of visual clutter from HVAC equipment.
The building's systems do have an aesthetic presence, more subtle inside than out. Most of the building's chimneys straddle two offices, for example, so that no one person has a whole shaft in his or her space, says ZGF partner Braulio Baptista. Outside, these chimneys are less discreet, jutting above the roof plane and breaking its continuity. The awkwardness of the move is the tradeoff for hyper-efficient mechanical systems that keep occupants comfortable and energy use low.
The building's mechanical systems weren't the only puzzle for the design team: because construction encroached on native flora, Susan Van Atta, the project's landscape architect, teamed up with a plant ecologist to conserve vulnerable species. “There are little multicolored flags on the site that indicate the location of each of the new seedlings we have sown,” says Van Atta. As elements of the master plan continue to rise, the foundation will monitor their progress.
Despite the challenges and risks associated with incorporating an unconventional mechanical system into the new headquarters, ZGF's design has earned rave reviews from the foundation's employees. “We're really in love with the building,” says Miller.
Size: 22,240 square feet
Cost: $24 million
Completion date: October 2012
ZGF Architects LLP
515 S. Flower Street, Suite 3700
Los Angeles, CA
Owner: Conrad N. Hilton Foundation
Architect of Record:
Engineers and Consultants
WATER RESOURCE ENGINEER
AUDIO VISUAL / IT / SECURITY CONSULTANT
Concrete Curing: 1100-Clear - W.R. Meadows
Green roof: Live Roof - Flora Source, LTD
Paints and stains: Carefree Earth Coat - Vista Paint
Special surfacing: Eco - Cosentino
Floor and wall tile (cite where used):
Flooring: TecCrete - Haworth
Other furniture: Canvas - Herman Miller
Downlights: ICL-LED650/ICL-LED900 - Pluris
Task lighting: eW Profile Powercore - Philips
Exterior: WP9SE-LED - Kim Lighting
Controls: WattStopper and Lutron
Photovoltaics SolarWorld 240 WATT - Martifer Solar USA, Inc.
Plumbing (fountains/ water saving fixtures)
Building management system Climatec
Additional Building Components or special equipment that made a significant contribution to this project.
HVAC-Passive Cooling Roof Unit: Energy Labs, Inc.
Radiant Flooring: Uponor
HVAC-Solar Hot Water Collectors: Sunda Seido 2-16 - Beijing Sunda Solar Energy Technology Co., LTD
Ceiling Tile: Ceilencio Custom Ceiling System - Decoustics
Exterior Sun Shades: S_enn shade - Nysan Solar Control
Charging Stations: ChargePoint, CT2001 Bollard Mount - Coulomb Technologies