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
Ph: 213-617-1901
Fax: 213-617-0047


Owner: Conrad N. Hilton Foundation

ZGF Architects LLP
515 S. Flower Street, Suite 3700
Los Angeles, CA
Ph: 213-617-1901
Fax: 213-617-0047

Architect of Record:
ZGF Architects LLP

Commissioning agent:
The Cadmus Group, Inc.
(formerly CTG Energetics, Inc.)
16 Technology Drive, Suite 109
Irvine, CA 92618;
Ph: 949-790-0010;
Fax: 949-790-0020

Interior designer:
ZGF Architects LLP
515 S. Flower Street, Suite 3700
Los Angeles, CA
Ph: 213-617-1901
Fax: 213-617-0047

Interior designer:
ZGF Architects LLP
515 S. Flower Street, Suite 3700
Los Angeles, CA
Ph: 213-617-1901
Fax: 213-617-0047

Engineers and Consultants
WSP Flack+Kurtz / Built Ecology
405 Howard Street, Suite 500
San Francisco, CA 94117;
Ph: 415-398-3833;
Fax: 415-433-5311

KPFF Consulting Engineers
4505 Las Virgenes Road, Suite 209
Calabasas, CA 91302;
Ph: 818-878-7887;
Fax: 818-875-0913

David Nelson & Associates
PO Box 270254
Littleton, CO 80127;
Ph: 720-981-4560;
Fax: 303-484-3230

Stantec Consulting Services
19 Technology Drive, Suite 200
Irvine, CA 92618;
Ph: 949-923-6085;
Fax: 949-923-6121

Van Atta Associates
235 Palm Avenue
Santa Barbara, CA 93101;
Ph: 805-730-7444;
Fax: 805-730-7446

Davis Langdon
515 South Flower Street
Los Angeles, CA 90071;
Ph: 310-393-9411;
Fax: 310-393-7493

Rocky Mountain Institute
2317 Snowmass Creek Road
Snowmass, CO 81654;
Ph: 970-927-3851;
Fax: 970-927-4510

1730 S. College Avenue Suite 302
Fort Collins, CO 80525;
Ph: 508-829-6000;
Fax: 508-829-5939

GeoSoils Consultants, Inc.
6634 Valjean Avenue
Van Nuys, CA 91406;
Ph: 818-785-2158;
Fax: 818-785-1548

Envicom Corporation
28328 Agoura Road
Agoura Hills, CA 91301;
Ph: 818-879-4700;
Fax: 818-879-4711

PlanNet Consulting
2850 Saturn Street, Suite 100
Brea, CA 92821;
Ph: 714-982-5800;
Fax: 714-982-5801

Kaminski Kaneko Design
6671 W Sunset Blvd, Suite 1580
Los Angeles, CA 90028;
Ph: 323-467-7404;
Fax: 914-381-3668

Bigelow Development Associates
6252 Cavalleri Road
Malibu, CA 90262;
Ph: 310-457-3310;
Fax: 310-457-5004

General contractor:
MATT Construction
9814 Norwalk Boulevard, Suite 100,
Santa Fe Springs, CA 90670

Nick Merrick
Ph: 312-491-1101
Nick Merrick © Hedrich Blessing



Structural system
Wide flanges and tube steel - Washington Iron Works

Exterior cladding
Concrete: Cemex ' Largo

Concrete Curing: 1100-Clear - W.R. Meadows

Glass: VNE24-63 Insulating Glass ' Viracon

Low-slope roofing: G410 Energy Smart Roof Membrane ' Sarnafil

Green roof: Live Roof - Flora Source, LTD

Interior finishes
Cabinetwork/custom woodwork: FSC Quartered European Ash Veneer - Wavell-Huber Wood Products, Inc.

Paints and stains: Carefree Earth Coat - Vista Paint

Special surfacing: Eco - Cosentino

Floor and wall tile (cite where used):
Space - Johnsonite (used below copy machine)
Ten/Thirty Collection #13010 - Mosa Tile ( ceramic floor tile in bathroom)
M-52 Shade-4 - Heath Ceramics ( kitchen backsplash)

Flooring: TecCrete - Haworth

Tall Story - Bentley Prince Street
Ecorib - EcoPath Walk Off Mat

Office furniture: Levels- Low VOC water based finish - Geiger desks

Aeron - Herman Miller
Setu - Herman Miller
Outdoor chairs - januswood - Janus Et cie

Vox Conference Table - Nienkamper
Vox Small Conference Table - Nienkamper
Vox Workroom Table - Nienkamper
Vox Veneer Flip Top Table - Nienkamper
Outdoor tables with janus wood - Janus et cie

Other furniture: Canvas - Herman Miller

Elevators/escalators: EcoSpace - Kone

Interior ambient : Covelight 26 - Focal Point

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)
Model SLN - Hubbell (solar water heater)
UT104E(V), 0.5 GPF low consumption washout urinal - Toto (urinal)
Solis, Model 8111 - Sloan (solar power flushometer)

Building management system Climatec

Additional Building Components or special equipment that made a significant contribution to this project.
Exterior Stone Veneer: Quartzitic Sandstone - Las Vegas Rock

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