Walk by most parking garages, and the view is of concrete and cars. Yet when employees at Edwards Lifesciences’ corporate campus in Irvine, CA, stroll pass their company’s four-story parking structure, they instead see living walls of grasses, flowers, and greenery. “Most parking garages are stark, cold, and gray,” says Scott Hutcheon, whose company Seasons Natural Engineering designed and installed this living wall. “Covering them with greenery gives instant aesthetic impact—and is a visible effort towards promoting nature.”
Green walls have been around for centuries, from the legendary hanging gardens of Babylon two thousand years ago to the manicured growing façades of British buildings as part of the Garden City movement in the early 1900s. The modern living wall movement can perhaps best be attributed to Patrick Blanc, a French botanist who first installed vertical greenery in 1986 at the Cité des Sciences et de l’Industrie in Paris. Now, hundreds of living walls have been planned and installed worldwide, and the quickly expanding market is expected to reach almost $700 million by 2017.
Parking garages, with their stolidly boring exteriors and built-in pollution from cars, in many ways seem perfectly suited for living walls. Exterior greenery can offset the heat island effect —in other words, soak up the sun’s rays instead of reflecting them back into the surroundings as most buildings do—as well as absorb storm water and neutralize carbon dioxide. As an additional bonus, all those plants are not only pretty, but the many varieties of grasses and flowers also attract bees, butterflies, and ladybugs.
“These walls are living ecosystems,” says Hutcheon. “Our system reenacts nature on a cliff, mimicking the moss that grows in between stones.” Edwards Lifesciences’ wall includes over 20,000 plants and 50 different varieties—including lavender, asparagus ferns, grasses, and salvia—spread across over 4,000 square feet. Recycled synthetic felt, which is both lightweight and flexible, provides the underpinnings for the greenery, and an underground water tank pumps water to irrigate the plants. “It’s the most sustainable system out there,” Hutcheon notes.
Indeed, that vertical layer of greenery is perhaps the most visible hallmark of a parking garage that incorporates sustainable ideals overall. Spread over two acres, and built to hold more than 1,200 cars, Edwards Lifesciences’ structure is massive. But it replaces an even-larger six-acre surface lot, where pedestrians now stroll through a landscape of native plants and grasses instead of across concrete parking spaces. Behind the lush foliage of the new structure’s living wall, natural light streams in through wide stairwells, there are electric car powering stations, and the whole project is topped with a solar canopy that provides much of the structure’s energy needs.
Though Edwards Lifesciences’ wall is said to be the largest hydroponic green wall in the U.S., there are other examples of living walls on parking garages dotted across the country, ranging from simple installations to ambitious designs. There’s a climbing trellis of honeysuckle and clematis vines on a parking garage in Philadelphia, PA, green walls on a freestanding garage in Durham, NC, an artistic mural sculpted out of plants on three sides of a Bellevue, WA library lot, and a Miami Beach, FL garage where birds perch in fabulously fluffy greenery. There’s even a project in the works in Tokyo where sheaves of grass will extend up the walls and a park will be built on the rooftop.
Do living walls instantly make parking garages more sustainable? Probably not, since parking structures are intrinsically designed around cars, with all the resulting pollutants and impact on the environment. Yet as Edwards Lifesciences’ garage has shown, with its incorporation of sustainability overall, living walls can become another important earth-friendly design element. After all, with their lush appearance and natural beauty, living walls could make any suburban parking garage not just greener—but also eminently more appealing to the eye.