Photo credit: 準建築人手札網站 Forgemind ArchiMedia/Flickr (CC BY 2.0)

Bosco Verticale (Italian for "vertical forest") is a breakthrough in sustainable architecture.

Although green roofs were once thought to be the future of sustainable cities, a recent project from architect Stefano Boeri takes the idea to a whole new level. His twin residential buildings, completed in 2014, takes advantage of every balcony, covering each building in beautiful, lush, greenery.

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Photo credit: Alessandro Bonvini/Flickr (CC BY 2.0)

Besides being a beautiful addition to Milan's skyline, the Vertical Forest is also incredibly practical. The foliage insulates the apartments from city noises and reduces energy consumption; during the summer the leaves block out hot sunlight and during the winter the bare branches let heat in. On top of the that, the plants produce boatloads of oxygen while cleaning up smog from the air.

Photo credit: Andrea Passoni/Flickr (CC BY 2.0)

The Vertical Forest, which won both the 2014 Emporis Skyscaper Award and the 2014 International Highrise Award, took three years to build. Growing the trees took two years alone. Each one had to be carefully pruned to fit below and between the balconies of the Vertical Forest. Condo owners are required to pay for regular maintenance and pruning of the plants by a landscape company.

Photo credit: 準建築人手札網站 Forgemind ArchiMedia/Flickr (CC BY 2.0)

Altogether there are 900 trees and 2000 plants in the Vertical Forest. The two buildings actually host far more vegetation than could be planted if the building were torn down and replaced by forest. On flat land, each Vertical Forest would take up 7,000 m2 or 1729 acres!

Photo credit: 準建築人手札網站 Forgemind ArchiMedia/Flickr (CC BY 2.0)

Hat Tip: TechInsider