By Kristi Myllenbeck, Cupertino Courier – July 8, 2016
Cupertino residents and curious followers of The Hills at Vallco project got a slew of details June 23 about what architects have planned for the proposed project, namely its green roof.
Laurie Olin, landscape architect for the project, and architectural designer Rafael Viñoly were on hand at Vallco Mall as part of an event put on by the American Institute of Architects. The duo answered questions from the public and gave details about the vision for the 58-acre site, which is proposed to include residential units, 2 million square feet of office space, and 640,000 square feet of retail and entertainment space.
The hot topic of the evening was the famed 30-acre green roof, which would include 3 acres of open space and 3.8 miles of public trails and paths.
Olin talked of the juxtaposition of urban and rural life.
“We know that so many people want the benefits of an urban life, but they also wish they could have the hills they used to have,” Olin told the audience. “They want the orchards, they want the vineyards, they want to go out and run on the hills. If you think of the nature of this place, well, it was this beautiful valley, with these beautiful hills and there was this natural plant community and animals. But then there was the cultural landscape–the orchards, vineyards, and farms–and it was very beautiful. So we’ve asked, can’t we have culture and nature? The answer is yes, of course.”
Questions from the community regarding the green roof spanned from water use, its landscaping, its amenities and how the project would hold up to an earthquake. Attendees were curious about the logistics behind the roof.
“People look at things and they’re not used to seeing–plants up there, of that scale–so they think it must be difficult but it’s actually not difficult,” he said. “Trees are not carrots. Their roots tend to grow out horizontally rather than down, most of them. So one of the things about this is that we only need 3 to 4 feet, sometimes 5 at the very most for the biggest trees, and then we need to give them horizontal root run. The grass doesn’t need deep soil. We know how to do the different depths.”
Olin said the project at this point is slated to have “several hundred” trees, but that number could evolve as the project progresses. He also said that the weight of the roof is not unusually heavy, and may even be less than projects that use large amounts of concrete.
The landscaping will consist of native grasses, trees, and other drought-tolerant plants that mimic the hills surrounding the Santa Clara Valley.
“Some of [the landscape] will be tan and brown,” Olin said. “Some of [the plants] are a little scratchy, [and] some of them get a little dry and yellow at certain times of the year. But we’re not going to have acres and acres of dry grass, that would be a fire hazard. So we’re having to balance these things.”
Water for the landscaping will likely be recycled water pumped in from a purple pipe or water reused from the development itself.
“What we now are doing on job after job, we try to figure out how to catch every raindrop that falls,” Olin said. “Catch it, keep it, use it, keep it clean, and now we’re starting to use recycled water. Our project will produce a lot of water that we can reuse. We do not have acres and acres of turf. We’re using native plants, you go up in the hills and they’re all alive.”
A local elementary school student in attendance asked what the green roof will offer for children.
“The minute you go into the park, you can walk right up from Stevens Creek and from the neighborhood, you can go right up,” Olin said. “We have a very large playground that we’re anticipating with a lot of things for children to do, to climb on, run and play. We also have places that are basically for free play where people can run, be outdoors, there’s trees, meadows, and a couple lawns for games and free play.”
For adults, there are plans for a rooftop beer garden, a winery with vineyards and a cafe.
Entrances, exits and paths along the green roof will also be fully accessible for those with disabilities and compliant with all ADA codes according to Vallco officials.
In addition, for safety precautions, guard rails, short walls and physical landscaping will be used to ensure roof users stay safely away from the edges of the roof.
Viñoly said that the community need not worry about the stability of the proposed project.
“What actually proved amazingly surprising to me was that the roof as a whole, this enormous mass, contributes to stabilizing the buildings below precisely because it’s so large,” he told the audience. “It’s like a dampening mechanism for the seismic forces. Essentially, the two structures, by friction, compensate each other, which is something you couldn’t do if the buildings were isolated.”
The Hills at Vallco project will go before Cupertino voters on Nov. 8.
To watch the entire discussion, visit Facebook.com/thehillsatvallco.