High-Rise Forestry

This pair of luxury housing high-rises under construction in Milan includes beefy cantilevered balconies that have been designed to support hundreds of fully-grown trees and shrubs.

Architect Stephano Boeri boasts that the project "is a model of vertical densification of nature within the city." The trees that will be suspended off of its balconies are equivalent to a hectare's worth of flat-land forest, while the homes inside the buildings represent five hectares' worth of single-family homes in the Italian suburbs.

It's called Bosco Verticale, or Vertical Forest.

These construction photos are by Daniel Iodice, and come from the Stephano Boeri Architetti website:

And a close-up of the tree boxes:


Here's the architect's vision of how the buildings will look when complete:

The plantings, which will include holly oak, European wild pear, and a mix of shrubs like Cain Apples and hawthorns, seem to have been chosen for their tolerance for constrained soil conditions and for their ability to improve the environmental quality inside and around the towers — shading the windows on hot summer days, insulating the apartments from city noise and particulate pollution, and filtering the apartments' grey water.

I first saw this project on the Green Futures blog, which included this critique:

Alexander Felson, Director of the Urban Ecology and Design Laboratory at Yale University, agrees that “there will potentially be microclimate and air particulate removal benefits”, but warns that the “overall energy required to construct a building that would support both trees and the wet weight of soil” places some serious question marks over its overall sustainability. He favors a more modest approach focusing on green roofs.

True, all that beefy steel and concrete required to hold up trees on an Italian balcony probably required the environmental sacrifice of a good chunk of China.

Still, I think Dr. Felson is missing the point (maybe he just can't see the forest for the trees?). This is a luxury high-rise, after all. While the architect Boeri is clearly interested in sustainability, he's also interested in creating a nice place to live for wealthy Milanese city-dwellers who can pay his commission. There are lots of luxury high-rises — the vast majority of them, actually — that blow their budgets waste construction material on much more masturbatory design flourishes.

What I find most interesting about these buildings is their approach to re-introducing wild nature into the city. I write about that idea often on this blog, but this project takes it to a new level (literally) by marrying a forest with a skyscraper. It's not merely creating a park that's geographically delineated from the rest of the city: it's integrating a forest with one of our most anthropocentric infrastructures: a high-rise apartment building.

That's pretty cool, not just for the people who live there, but for everyone in Milan who will be able to look at a vertical forest in their city's skyline.

Notwithstanding the technical questions of the construction project's sustainability, the buildings still presents an extremely bold vision of a sustainable city — a city in which nature is prominent and integrated into daily life.