We may need to start building our parks in the sky. In the 1850s, New York City needed a place to escape from its own urban crush. It was easy enough to evict more than a thousand poor tenement dwellers and re-landscape the heart of Manhattan, creating what we know as Central Park. Today, such a project would prove far more difficult, if not impossible, in most of the world’s major cities. Vertical greenspace may be one answer to that problem.
The Bosco Verticale towers taking shape in the northern Italian city of Milan, although private residential towers, show the technology is more than possible. Designed explicitly to house at least as many trees as people, the buildings make room for plenty of apartments (ranging between $870,000 and $2.6 million for the penthouse) as well as 730 trees, 5,000 shrubs and 11,000 ground plants, according to the U.K.'s Daily Mail.
The vertical forest spreads out one hectare of woodland across 27 floors. And it’s only just the beginning. The $90 million buildings are the first in a series of proposed green belt project called BioMilano, which could encompass dozens of abandoned farms on the outskirts of the city.
This doesn’t make them particularly expensive. Accommodating the vegetation only added about 5% to construction costs, according to the Financial Times. Compared to the equivalent area for individual homes and woodland, at least 12 acres of land, and 2.5 acres of forest, would be needed. Boeri Studios, its creators, hope the buildings set a new standard for green design.
Other architects are working on the same challenge by taking the biological metaphor to extremes. Harmonia 57, a building in Brazil designed by Triptyque, actually "breathes and sweats." Plants embedded in porous concrete walls are watered with a mist that shrouds the whole building. It creates the appearance of a building returning to the jungle, rather than the urban grind.
But most green buildings today merely evoke the forms found in nature. Few ever actually invite it in to play. We settle for energy efficiency and responsibly sourced materials instead. While that’s all well and good, architects are finally starting to craft biological buildings in cities that blur the line between green space and living space.