The Gates Foundation: Seattle's Scenic Sustainability Showcase

Kyle Cavaness, LASN

The Bill and Melinda Gates Foundation's central headquarters in Seattle, Wash. includes two four-story, energy-efficient buildings; green roofs and extensive plantings; and a sustainable, rainwater-fed water feature planted with rushes and cattails beneath a wooden boardwalk. After more than seven years of planning and construction, the site was awarded LEED Platinum status in October 2011.
Photo: Timothy Hursley

In 2004, the Bill and Melinda Gates Foundation identified the need for a permanent headquarters for the international organization, consolidating five disparate locations into one, where everyone could work together and collaborate.

When first imagining the campus design, architects at Seattle-based firm NBBJ were inspired by a map of the globe that illustrated the pathways of world commerce and travel. The designers mapped out pathways of their own, originating from a point in Seattle to places around the globe where the Foundation is working to improve health and establish infrastructure to meet basic needs in 100 countries.

A publicly accessible fern garden and overlook highlights the reception building off of Republican Street. The importance of natural light to the project both enhanced the visual spectacle of the complex and improved energy efficiency, contributing to the campus's LEED Platinum status.

These initial drawings developed into the outward reaching "arms" of the campus buildings. While conceptually connecting the foundation to its global work, the arms are grounded in Seattle, resting on buildings firmly entrenched within the Seattle street grid. In concert with the campus architecture by NBBJ, Gustafson Guthrie Nichol (GGN) designed the campus landscape to be an outdoor working environment that would stimulate collaboration and problem solving. A series of serene spaces reflects the organization's Pacific Northwest roots, with a growing forest canopy, rainwater-fed water gardens, courtyards of salvaged cobble, and extensive green roofs.

The campus was designed to complement its location in an urban neighborhood called Uptown in Seattle, Wash. The 900,000 square-foot complex replaced an asphalt parking lot with a space built to blend into the serene natural character of the area. From the beginning, the foundation wanted a space that functioned as an outdoor work environment, so workers could be informed and inspired by nature and the outside world.

The Campus Heart Plaza includes moveable outdoor seating and Big Leaf maples to provide shade. The courtyard, surfaced with salvaged cobble and lined with native vegetation, has become a popular destination for employee lunch breaks and outdoor meetings.

The landscape format reinforces street edges and aligns campus features, from pathways to water edges, with the surrounding streets and buildings. The materials and functions of the landscape are informed by the area's natural history as a wetland marsh.

The rainwater-fed central pool contains native aquatic plants, including reeds and cattails. A one-million-gallon cistern beneath the complex, which holds and processes rainwater from building roofs, feeds the water feature, also fulfilling irrigation needs and flushing toilets in campus buildings. The cistern reduces the campus's potable water needs by 80 percent.
Photo: Sean Airhart/NBBJ

Low-Impact Landmark
The concept for the space grew from long-term thinking. The foundation wanted to create a sustainable, low-impact campus built to last 100 years, instead of the typical 20-30 year timeline envisioned for typical office space projects. The Gates Foundation campus incorporates the native landscape, local materials, natural processes, and an integrated sustainable system that includes: the harvesting of rainwater, reducing potable water consumption, maximizing solar energy use, and minimizing energy use. Despite increased initial construction costs, the amalgamated approach to sustainability and efficiency is projected to pay for itself within 30 years – still early in the expected lifespan of the complex.

A native big-leaf maple tree was installed at the entrance to the campus, requiring a construction crane to lift the 10,000-pound, eight-inch diameter mature tree over the construction fence. The tree has become a campus landmark, drawing visitors through an open-air entry court to the front door.

Native and edible plants – including blueberries and Big Leaf maples – surround a central courtyard that "floats' on water gardens planted with native reeds.

Rainwater is filtered by more than half an acre of green roofs and directed from paved areas into the unique million-gallon cistern. To protect the shallow, 6-inch soil base, the living roof is not open to the public.

The wooden boardwalk circulation system includes seating over the water garden, designed to maximize opportunities for outdoor meetings. The Gates Foundation wanted the outdoor areas to be an extension of the indoor meeting and office space, available for collaboration and problem solving.
Photo: Sean Airhart/NBBJ

"The materials and functions of the landscape are informed by the site's natural history as a dark-watered bog in a plateau meadow that absorbed and filtered rainwater," said GGN design partner Shannon Nichol.

The campus's reed and cattail planted pools, green roofs, and natural filtration system were included for their sustainability benefits and aesthetic benefits alike. The plantings mix native species like vines and maples with non-invasive, drought-tolerant plants. All add seasonal color.

Mature London plane trees, planted when they were already 15- to 20-feet tall, provide natural shade, texture, and greenery along the street.

Native and edible plants, including blueberries, line the entrance of the Gates Foundation. A mature big-leaf maple tree was also installed at the campus entrance, instantly becoming a 10,000-pound, eight-inch caliper campus landmark, drawing visitors through the open-air entry court to the front door.

The landscaping provides a natural buffer between the sidewalks and the foundation's buildings. Benches can give respite to walkers and those waiting for the many Metro buses along 5th Avenue North. A river of eight poems was interspersed along the top of a seat-height wall facing Fifth Avenue North, rounding the corner on Mercer Street. The collection was taken from Africa, Asia, Europe, and North America, including the Pacific Northwest's own Theodore Roethke and the Middle East's Taha Muhammad Ali.

"The environmental qualities of the campus landscape are the natural outcome of designing for the Foundation's strong philosophy of "local roots and global vision'," Nichol said.

The form-liner pattern in the concrete planter walls was inspired by the site's natural history as a dark-water bog. The rain harvesting mechanisms and green roofs were inspired in part by the natural stormwater filtration performed by the marshland.
Photos: Sean Airhart/NBBJ

No Water Wasted
Water conservation was guiding principle of the project. The vision for the campus was to enhance the local watershed by restoring habitat; improving stormwater management; and reducing the office space's demand for potable water. Two acres of green roof, installed atop the parking garage and main buildings, meets this need by absorbing and processing as much as 90 percent of rainwater received – no small feat in the rain-soaked Pacific Northwest. The remaining hardscape runoff and rooftop drainage is collected in the rainwater storage tank.

To minimize the use of potable water in the landscape, the foundation and design team developed a rainwater harvesting system unique in Washington State, made possible by a one-million-gallon storage cistern installed beneath the campus.

The right-angled forms of the boardwalk complement the sweeping, distinctly rounded architecture, as an interpretation of the "local ground, global vision" theme of the campus.
Photos: Timothy Hursley

Located in the complex basement, the reservoir collects about 2.37 million gallons annually. The water is air-chilled at night, when lower outdoor temperatures improves the energy efficiency of the equipment, and then recirculated through the building's air conditioning during the day. Using air-cooled rather than water-cooled equipment saves millions of gallons annually. The water in the 16,000-square-foot concrete tank also fills and replenishes the water feature, irrigates landscaping and flushes the toilets in campus buildings.

The combined water needs of the office buildings and landscape irrigation – about 1.6 million gallons annually – are met almost exclusively by the underground cistern. Filter backwash and overflow from the storage tank and water feature are discharged to a combined sewer system. Combined with efficient plumbing fixtures, these systems reduce the campus's potable water use by nearly 80 percent. During the three-month summer dry season, cleaners empty and scrub the tank so it will be ready when rainwater collection resumes in the fall.

The campus was designed to bring life and nature to its location in an urban neighborhood in Seattle, Wash. The 900,000 square-foot complex replaced an asphalt parking lot with a sustainable, low-impact campus built to last 100 years, instead of the 20-30 year timeline envisioned for typical office space projects.

LEEDing The Way
Phase one of the campus opened in May 2011, seven years after the need for a new headquarters was first identified. The project received LEED-NC (Leadership in Energy and Environmental Design for New Construction) Platinum certification from the United States Green Building Council, the largest LEED-NC Platinum accreditation in the world for a non-profit foundation.

LEED accreditation is based on criteria in five categories: site sustainability; water efficiency; energy efficiency and atmospheric impact; materials and resources; and indoor environmental quality. To earn platinum certification, the new construction must earn 80 or more points out of the 100 points possible on the LEED scale.

Wooden street furniture integrates the campus with the sidewalks of 5th Avenue, lined by plantings to create space between the office space and the street. Locals wait for the bus on benches at the edge of the complex.
Photos: Timothy Hursley

"Perhaps most satisfying is that this sustainability achievement was the result of an integrated design process, not a race to acquire points," said Cormac Deavy, project director and design team leader for Arup. "The mechanical systems were selected for their return on investment, operations and maintenance considerations, future flexibility, and their ability to improve the indoor environmental quality for the staff."

During construction, the builders locally sourced as much of the raw materials as possible, and implemented efficient project-waste-management practices to reduce the build's environmental impact.

"Over 20 percent of the project was built with recycled content and regional materials, resulting in boosting the local economy for 21 subcontractors that extracted and manufactured materials within 500 miles of the jobsite," said Yancy Wright, sustainability director at Sellen construction, the project's general contractor. "By focusing on what was best for the overall project, we were able to reap benefits far beyond initial project goals."

The campus design reduces overall energy use by 39 percent, non-potable water use by 79 percent, and returned 40 percent of the 12-acre site to green space. The adjacent public parking garage, featuring a 1.4-acre living roof built via a public-private partnership between the foundation and the city of Seattle, was separately awarded LEED Gold certification.

The LEED Platinum certification awarded to the Gates Foundation campus was the result of an integrated team of designers, engineers, and contractors guided by long-term thinking, a natural offshoot of the Bill & Melinda Gates Foundation's overall philosophy of good stewardship of the environment and the neighborhood. The lasting sustainability of the campus is meant to provide the best possible space for foundation staff to do their best work.

Team List:
Architect/Interiors & Workplace/Lighting/Environmental Graphics: NBBJ
Civil & Structural Engineer: KPFF
Development Manager: Seneca Group
Electrical Contractor: Cochran, Inc.
Food Service: Hammer Design Associates Inc.
General Contractor: Sellen
Landscape Architect: Gustafson Guthrie Nichol
Landscape Contractor: Teufel Landscape
Mechanical Contractor: McKinstry
Parking: Walker Parking
Structural Mechanical Electrical & Plumbing; AV/Acoustics & IT: Arup
Technology Consultant: TechPMgroup
Vertical Transportation: HKA Elevator
Waterproofing: Morrison-Hershfield
Wind Solutions: RWDI
Workplace Consultant: AMA Alexi Marmot Associates Ltd.
Workplace Consultant: Judith Heerwagen