Gardens are sprouting on top of the city's buildings, bringing environmental benefits as well as beauty
New York's rooftop farms improve the view and the environment. This is the Eagle Street farm. Photograph: Mike Di Paola/Getty Images
Central Park aside, New York City is better known for its dense concentration of towering buildings than its bountiful greenery. So it's appropriate that the city is starting to use its ample supply of rooftop surfaces to make up for the lack of green space at ground level. Roof use has gradually increased in the city, with boutique hotels, art exhibitions, film screenings and even a women's prison in Manhattan all getting in on the act.
But the recent rooftop trend has been more environmental in nature. Green roofs – a system of plants growing on waterproof membranes on top of buildings – are sprouting across New York City's five boroughs. Given the potential to reduce greenhouse gases, increase energy efficiency and capture storm-water run-off, it's easy to understand why.
"Most of this work is small in scale so far, but it should get us all thinking," said David Smiley, assistant professor of architecture and urban studies at Barnard College. Green roofs are seen as particularly beneficial in New York City because of their ability to absorb up to 70% of the rainwater that would otherwise drain away. The city – built on islands around a harbour and two rivers – has long struggled with excessive run-off after heavy downpours; it overwhelms the drainage system and then overflows with raw sewage. Con Edison, the city's energy supplier, led the way in 2008 by planting thousands of green and purple sedum – ideal for its absorbent leaves and tough roots – on the roof of its building in Long Island City, across the East River from Manhattan. Then two urban farms opened on top of warehouses in Brooklyn (Eagle Street) in 2009 and Queens (Brooklyn Grange) in 2010, growing organic produce. Now, it's not just commercial operators greening their roofs.
"We're slammed," said Marni Majorelle, who founded Brooklyn-basedAlive Structures in 2007 to help people to convert their rooftops into usable spaces. "There's a growing demand for green roofs from homeowners and developers. I see it as part of people's plans – so many architects now include it. It's a new chapter for New York."
According to a 2008 New York Times report on green roofs, the city has 944m sq ft of rooftop surfaces, but limited records of how much is used for such purposes. It still lags behind Germany and other US cities such as Chicago and Seattle, where – as Dwaine Lee, a green infrastructure professional, recently told an audience of affordable housing developers – green roofs were embraced years ago.
But Lee thinks New York City is beginning to catch up, thanks to tax incentives, grants and ground-level enthusiasm among developers and homeowners. In 2008, tax breaks began to be given to developers and building owners who install green roofs, providing significant savings on annual property bills. Installation costs have also fallen – from the relatively high level of $30 per square foot to closer to $20 per square foot for some conversions.
"It will keep growing, because the cost is coming down and the manufacturers of roofs are getting into the game," said John Coogan, ofOCV Architects. The firm creates various types of roof space, predominantly alongside non-profit-making organisations in affordable housing units. It designed its first green roof in 2004 and has completed a dozen more spaces since – most recently a rooftop recreational area in a senior citizens' home in the south Bronx. Some think green roofs are just the tip of the iceberg. In her 2010 article Clip-on Architecture: Reforesting Cities for UrbanOmnibus, a project run by the Architectural League of New York, architect Vanessa Keith predicts an array of innovative ways to retro-fit buildings – from roof ponds for cooling to electricity-generating water walls. "Perhaps the current dilemma, rather than being seen as a death sentence or a depressing indictment of wasteful society, can provide an opportunity to rethink and retool our existing way of life," she argued.
One of Keith's suggestions – white roofs – has already being rolled out by Michael Bloomberg, the mayor of New York City. The NYC CoolRoofsproject, which paints reflective white coatings on roofs, reduces energy use, cooling costs and carbon emissions. The counter on the city government's website claims 1,355,869sq ft has so far been "cooled" in the one-year-old project.
Meanwhile, urban farming doesn't stop at plants. David Graves has been keeping rooftop beehives, and selling the resulting honey at farmers' markets, for more than a decade. Graves uses about 12 friends' rooftops, from Harlem to the East Village, to store the hives. "It's important to use these spaces," he said. "Rooftops are a waste of space – so many are empty that could be used to benefit the environment." Standing eight floors above the hum of lower Manhattan, Graves gazed out over the rooftops and added wistfully: "Wouldn't it be great if one day you flew over New York City and it was all blue with lavender? The bees would love that." Although the city's rooftops may be going green, with white in between, the day they go lavender blue may still be some way off.
SOURCE: http://www.guardian.co.uk/environment/blog/2011/may/19/green-roof-gardens-plants-new-york
