Eco-friendly residential tower in Paris

Eco-friendly tower
Yet, the architects wanted to create a beautiful pair of buildings as well. That is why they planned for the ledges to be lushly planted, so, collectively, the towers appear to resemble hanging gardens, with plants and vines spilling over each terrace. Ingenhoven will include vegetation on the rooftops, too, so between the public green space at street level, the hanging gardens, and the green roof, the new development will provide a continuous planted landscape, from ground to sky. In addition to its aesthetic value, the greenery will help increase the energy efficiency of the buildings. Mori expects to finish the towers by 2019, just ahead of the Tokyo Olympics, in 2020.

What about the huge amount of energy expended to make the concrete, steel and glass for a building? Singh says the Beacon’s concrete will be produced as near as possible to the site and also that 35,000 tonnes of excavated chalk and clay will be used to infill non-load-bearing walls in the building. That’s rather than the usual practice of carting all that spoil away in hundreds of petrol-guzzling lorries.

But don’t go too high, he warns. “Buildings lose resilience, such as when the power goes out you lose water and fire protection because the pumps don’t work, and it’s too far to walk down and up the stairs. High density is green and good, but you can have too much of a good thing.”

“There are many reasons that high-rise living is green. We travel much shorter distances going vertically than horizontally, and lifts are probably the most energy efficient means of transportation on Earth except for a bicycle,” says Lloyd Alter, adjunct professor at Ryerson University in Toronto and design editor of the eco-architecture website Treehugger.com. “When you have a lot of people living together in tall buildings, then a bicycle is all you really need because there is enough of a population density to support stores, public transit and offices.”

RB12 was first built in the 1970s and, like many of the city's buildings from that era, had very few green credentials. Rather than demolishing it, property developer Natekko asked Triptyque to look at ways of reducing its energy consumption.

“There’s a bigger agenda here,” he says. In the UK, air pollution kills 40,000 people prematurely every year, and across the world that number is 5.5 million.

Eco towers are spreading. A fad perhaps, but not necessarily a bad one. Stefano Boeri is due to build another Bosco Verticale, called La Tour des Cedres in the Swiss city of Lausanne. Like his Milanese project, this tower will be covered in coniferous trees, in order to trap dust, absorb CO2  and release oxygen.

Intriguingly, the 17-floor tower – designed by Lumiere Developments – is popping up not in London but in the Hertfordshire commuter town of Hemel Hempstead. The area was planned as a new town in the Forties by the late Sir Geoffrey Jellicoe – who was himself a pioneer of architecture that mixed technology with supposedly green credentials. In the Sixties, Jellicoe proposed a plan for an even grander new eco town near Staines, Middlesex, of connected tower blocks called Motopia, where cars would, incredibly, travel on the roofs of the buildings – all of which were to be set in generous parkland. This utopian idea, like something from a JG Ballard novel, was never realised. Transport has also been a big part of The Beacon’s modus operandi – electric cars and electric bikes will be available to residents. The car park will be automated and your car parked by a robot. “We have this wonderful underground parking solution – it’s pretty cool, and it’s also in the Shard,” says Singh. “You don’t have so many emissions down there as it’s automated – and it takes up less space.”