Peter Walker

Minimalistic Design with Enormous Impact

Peter Walker, FASLA, has become a legend in his own time. One of the leading landscape architects in the Modernist movement, Walker was chosen to help design and build the National 9/11 Memorial in New York City, and his list of accolades continues to expand. All in all, he has received over 70 design awards in the regional, national, and international spheres. In 2007, Walker was recognized with the coveted Cooper Hewitt National Design Award. In 2005, he was the inaugural winner of the Sir Geoffrey Jellicoe Award from the International Federation of Landscape Architects, the highest honor given to a landscape architect. He has also received the Honor Award of the American Institute of Architects, Harvard's Centennial Medal, the University of Virginia's Thomas Jefferson Medal in Architecture, and the American Society of Landscape Architects Medal, among other honors, for his moving, strikingly simple approach to landscape design.

A Winding Path

Walker's career path was not typical. At the University of California, Berkeley, he initially pursued journalism with a focus on developing and producing newspapers and magazines. He soon reexamined his choice and browsed through the course catalog, landing on landscape architecture. Walker recalls that this subject devoted about a third of its time to art courses, a third to technical courses for landscape architecture and landscape design, and the remaining third to general curriculum—history, philosophy, and other subjects. "I wasn't thinking about being a landscape architect," he says."I just thought that that would be better preparation for magazine production and publishing. So I jumped over there and ended up finding that I liked it." Later, he fulfilled his journalism dream and combined his two passions by founding Spacemaker Press, which he ran from 1996 to2005. It continues to publish books dedicated to the evolution of landscapes.

Walker holds a Bachelor of Science in Landscape Architecture from UC Berkeley. He received a Master of Landscape Architecture from Harvard University's Graduate School of Design in 1957, capturing the school's Weidenman Prize. He has also earned many honorary degrees, including an Honorary Doctorate from The University of Illinois and an Honorary Doctorate from The University of Pretoria. While still in school, Walker got his start working for renowned landscape architect Lawrence Halprin in San Francisco. Soon after, while studying at Harvard, he worked part time for influential landscape architect and professor Hideo Sasaki. Walker joined the firm full time just one year later. In 1957, the two formed Sasaki Walker Associates. Two years afterward, Walker started the firm's West Coast office.

During the 1970s recession, Walker founded the SWA Group, for which he served as Chairman of the Board until 1983, when he left to form a smaller firm, now known as Peter Walker and Partners (PWP) Landscape Architecture. PWP currently has seven principals and 35 employees and handles a few projects a year, "specializing," as Walker says, "in bringing them to a very high level of completion." The firm focuses primarily on institutional work, including universities, cities, and cultural centers; landmark projects like the National 9/11 Memorial, Newport Beach Hall and Park, and the United States Embassy in Beijing; larger urban parks and plazas; and corporate campuses for such firms as Pixar, Weyerhaeuser, Novartis, and VMware®. Their work extends all over the world. The firm is widely considered one of the busiest and most successful landscape architectural practices in the world.

The National 9/11 Memorial: Shelter for the Voids

Exactly one decade after the single largest terror attack on United States soil took the lives of almost 3,000 people, the National 9/11 Memorial in New York City opened in their honor on September 11, 2011. Several years earlier, Walker had been brought in by the jury overseeing the competition to work with architect Michael Arad to help Arad realize his vision for the Memorial—two large fountain-lined voids marking the footprints of the fallen Twin Towers and carrying the names of those lost in the 9/11 attacks and in the 1993 bombing attack on the World Trade Center. Walker and his firm balanced the stoic stone memorial with a lush park to encourage reflection and respite for visitors as well as the inhabitants of Lower Manhattan, one of the densest neighborhoods in the country.

The Memorial covers seven acres, approximately half of the World Trade Center site. In addition to the sheer enormity of the site, Walker and his team at PWP have had to contend with the challenge of managing work for an unusually large number of clients at the local, state, and federal level, including developer Larry Silverstein, the New York governers (so far there have been five during the length of the project), the Mayor, the 9/11 Foundation, the state-city Lower Manhattan Development Corporation, the Port Authority of New York and New Jersey, the Public Works Department, the State Transportation Department, and various security agencies, in addition to the 3,000 families and 10,000 relatives touched by this tragedy. The scope of the site poses many challenges, as well. Although the Memorial Plaza opened on September 11, 2011, the entire site was not completed at that time. Four towers rise from the street (one will be the tallest in the country), and several seven-story buildings take shape below, including the Transportation Hub with subway stations, a shopping center, the buildings' basements, a chiller plant, a parking garage, and a museum—all built simultaneously. "It's almost like three-dimensional chess. I'm not sure how you do that, but so far, so good," Walker says. The National 9/11 Memorial is also unusual for its sweep of time. Given its importance in United States history and the sheer amount of work to be accomplished, the project requires a long time frame. Typically, Walker will work on a project for a year or so, then bid it and build it within five years. At the time of its opening, Walker had been working on the Memorial for seven years, and the project was not yet complete.

To infuse the Memorial with signature Modernist ideas, Walker drew on his vast experience. "Some of the ideas in the National 9/11 Memorial are ideas we've been working on elsewhere," he says. "We've been building on top of buildings for 20 years, and now about half our work is on buildings. That shows a trend towards the urban. And I've been one that says you don't do naturalistic—you don't try to make a roof look like Central Park—so a lot of the vocabulary of the Memorial has come out of these previous projects."

I like minimalism because one of the things you do is make people see natural process more strongly. For instance, if you don’t have a bunch of shrubs it’s much more evident when spring comes, when fall comes, and when winter comes. So in a way it makes the plant material the star; one of our principles is to try to use plant materials in a way to show them off.

– Peter Walker, PWP Landscape Architecture, Berkeley, CA

One of these projects was the Sony Center in Berlin, Germany, where he collaborated with German architect Helmut Jahn. Walker was challenged to make a plaza the size of a football field work visually even when it wasn't filled with people, much like the expansive Memorial site.

Another example was a project in Saitama Prefecture, Japan, just north of Tokyo, where the largest sports arena and the tallest building in the country surround the Keyaki Hiroba Center, which also contains a train station. "The park is up on top of a three-story building, and we won this project by not doing something naturalistic," says Walker. "We did a grid of Zelkova trees, which have a beautiful vase shape. And even though its name is Saitama Plaza, everyone calls it Zelkova Plaza. The interesting thing is there's nothing natural in it except these trees. That's what caught everyone's imagination." A self-professed Minimalist, Walker would argue that the spare design allowed people to focus on the trees. "I like minimalism because one of the things you do is make people see natural process more strongly. For instance, if you don't have a bunch of shrubs it's much more evident when spring comes, when fall comes, and when winter comes. So in a way it makes the plant material the star; one of our principles is to try to use plant materials in a way to show them off."

Through this philosophy, Walker prefers to focus on a few objects and use only a few meaningful materials. "I'm interested in how few things you can use that have multiple interactions, for instance where a group of trees will throw shadow. I'm interested in where people might sit—not just benches, but steps, walls, all of that. I'm always interested in trying to make fewer things do more things. It's more than an interest in reductiveness—it's more of an artistic interest," says Walker. This approach is evident throughout the National 9/11 Memorial.

Each component in the Memorial was selected for functionality as well as art. The original plan called for stone throughout the seven acres. Walker reduced the stone by about half and instead sculpted the ground with grass and trees to soften the space. More than 400 swamp white oak trees were hand-picked and then tended in New Jersey for five years before being transplanted into the Memorial. A planting's corridor with 1.8-meter depth filled with soil and traversed by irrigation pipes lies between the walk and the ceiling of the buildings below. These trees can live for up to 350 years, their trunks grow straight, and their leaves turn golden in the fall.

They stand at nine meters now but will more than double in height when mature, sheltering the space from too much light and noise. A callery pear tree that survived the attacks and is now named "The Survivor Tree" is also part of the design. Walker carefully selected furniture, lighting, and other objects to keep the ground plane unimpeded. "When you're around the voids it seems like a plaza, but when you look out it seems more like a park," explains Walker. He had to design the ground to be perfectly flat so the nine-meter deep voids could work visually. "The trick was to keep it flat so the voids were cut into it in a recognizable way," he says.

In addition to its simple beauty, the design is sustainable. Containers capture every drop of water that falls on the Memorial, and pipes carry the water down into two 568,000-liter tanks under the Memorial. The collection is completed in the early part of the year to capitalize on heavier rains and then used in the late summer and early fall when there is less precipitation. This eliminates the need to rely on city water and prevents the ground from dumping water into the city's supply. "It's the largest sustainable project in New York," says Walker. "And maybe in the U.S.—I'm not aware of one of this magnitude."

The magnificent fountains are also efficient, even though their original design was not. Initially, they would have consumed more energy and therefore cost more to run each year than it had cost to build them. Walker's fountain consultant, Dan Euser, discovered the solution, which Walker describes as "brilliant." He created a comb-like weir, or dam, for the water to cross. Instead of 2.5 cm of water crossing the fountain, only one-tenth that amount flowed over. This cut energy costs significantly without detracting from the fountain's powerful effect. One of the largest ever built, the fountain has sides that span more than 488 meters. 113,500 liters of water a second spill over the weir and shoot out 1.2 meters to cascade nine meters below. Reflecting pools of almost 4,000 meters2 fill the bottom, surrounding a square void that appears infinite. Along the top, bronze parapets line the rim with the names of the victims. These names are backlit, and the metal is heated or cooled to be comfortable to the touch throughout the seasons.

The design has met with critical acclaim, yet in the end what matters most to Walker is the feedback from the families and friends of the victims. "I don't care what the critical reaction is nearly as much as I care what the emotional reaction is from the families and friends. As much as we're doing this for the government, we were doing it for the families and the people who come there," he says.

An Evolution of Design

Walker and his firm used Vectorworks® Landmark software to create and model the National 9/11 Memorial, as they do with all of their designs. "We always use Vectorworks on preliminaries. That's typically the way we work—everyone here has to do that. It's much more flexible, it's much more refined than AutoCAD®," notes Walker. Walker commends the three-dimensionality. Since it's so difficult to draw, the ability to quickly maneuver a design in 3D is tremendously helpful. He appreciates the fact that you can blow up a detail to its actual size in order to see it better. "That's a real plus as far as I'm concerned." He compares computer modeling to the days when everything was drawn by hand, saying, "It isn't just the savings of time—it's a completely different world. When I first started and I went to work at Halprin's office, the first time I ran into trouble was when I put a coffee cup on the drafting table and everybody said, 'if you spill that coffee, you could ruin the whole page,' which would cost tens of thousands of dollars. Now, of course, we put the drawings on the floor as they come spitting out. That's the change that I've seen—drastic change."

We always use Vectorworks on preliminaries. That’s typically the way we work—everyone here has to do that. It's much more flexible, it's much more refined than AutoCAD.

– Peter Walker, PWP Landscape Architecture, Berkeley, CA

Walker says his philosophy "has developed over the years," and he notes, "I don't think it's changed. I started doing the things that the California landscape architects were doing, which were basically backyards—that was what Modernism was. And landscape today is very much affected by what we have done because everybody is using the techniques that we developed. That's our goal, and to some extent we've accomplished that and we want to keep pushing this as far as we can for as long as we can."

By shaping a strong tradition of Modernist landscape design in the U.S. and throughout the world, Walker has helped to create a vocabulary that continues to drive design. Through the National 9/11 Memorial and many other notable projects, he has fashioned spaces that commemorate some of the most important moments in history—living monuments that will continue to thrive for years to come.