In a July TED talk on energy innovation, tech entrepreneur and Nanoholdings CEO Justin Hall-Tipping spoke about the importance of challenging our perceptions of "normal". The tendency of human beings, he said, "to look at our world through the lens of 'normal,' is one of the forces that stops us developing real solutions." And while Hall-Tipping was talking about his current work with a group of "incredibly kind and brilliant" scientists – towards the lofty goal of decentralising energy and, essentially, making it free for one and all – it's comforting to note that the art of taking a "magic look at the world," which Hall-Tipping points to as a key starting point for innovation, seems to be catching on.

It would be hard to find a more obvious example of a "magic look at the world" than the development of Milan's Bosco Verticale – two residential towers in the northern Italian city that are on their way to becoming the world’s first vertical forest. As the Financial Times reported last week, the project, the brainchild of architect Stefano Boeri, includes a balcony planted with trees for each apartment. "In summer, oaks and amelanchiers will shade the windows and filter the city’s dust; in winter, sunlight will shrine through the bare branches," says Christopher Woodward, director of London’s Garden Museum, writing in the FT. 

But, as Hall-Tipping points out during his talk, another key part of successful innovation – and to fixing some of the world's thornier problems – is to convert the magical into a working reality. So, while Boeri "begins his presentation with Ovid’s fantasy of the nymph Daphne being turned into a tree," he quickly switches to the practical, says Woodward, by showing that to achieve his building's green metamorphosis adds only 5 per cent to construction costs. Boeri also argues that the greening of high-rise buildings is a necessary response to the sprawl of the modern city.

Boeri's magical 'vertical wood' has been made possible due to a new collaboration between architects, engineers, and botanists, says Woodward. "(He) has had to explain many times the engineering and horticultural solutions required for an oak tree to grow up to 9m high on the 20th floor of a busy modern city. At the same time, this new movement is a visionary reclamation of the nature that has vanished from our cities."

So how will it work? According to Gizmag, the towers, measuring 110 and 76 meters, will house over 900 trees, not to mention a wide range of shrubs and floral plants – essentially the equivalent to a 10,000 square meter forest, growing vertically. As well as being what Boeri describes as a "device for the environmental survival of contemporary European cities" (he also describes it as part of the “living architecture” movement, says Woodward, which differs from the legislation-driven “green architecture" model in that it focuses on "how cities should feel"), the greenery will help to produce humidity, absorb CO2 and dust particles, and produce oxygen, thus improving quality of life for residents, while also shielding the building from radiation and noise pollution. The towers will house irrigation and filtering systems which will recycle grey water for upkeep of the plants, while solar PV will help power the building.

All this will cost an estimated €65 million ($US87.5 million), says Gizmag, and is just the first stage of Boeri's proposed BioMilano – a grand plan to create a green belt around Milan, encompassing 60 abandoned farms on the city's outskirts and restoring them to community use.