A fleet of 20 flying robots built a 600m-high vertical village – well, a 1:100 scale model anyway – designed by Fabio Gramazio and Matthias Kohler, both professors in Zurich, with the live construction the highlight of Flight Assembled Architecture, an exhibition at the FRAC Centre in Orleans, France.

The model is basically layers of irregular rings of foam bricks separated with gaps bridged by the overlapping bricks in the layer above, making it not unlike the base of a hollow tree. Some 1,500 bricks, each of about 100g and measuring 10cm high, 30cm long and 15cm wide tapering to 12cm in the middle, were used. The whole tower could have been built in two days, but it was slowed down and done in sections over four and a half days, including a public demonstration in December.

What the audience witnessed was the flying robots taking off from platforms mounted on the wall and buzzing around with the sound of a hornets nest. Each gripped a brick by puncturing it with pins. The bricks landed with a clunk – research found that soft-landing them introduced potential turbulence problems. The vehicles, four-rotor affairs, were adapted by Professor Raffaello D’Andrea of the Swiss Federal Institute of Technology (ETH) in Zurich, and were programmed only to fly in space not being occupied by another vehicle nor the tower itself.

D’Andrea has been researching new applications for autonomous flying vehicles at the ETH since 2008, and met the tower’s designers (and ETH colleagues)?Gramazio and Kohler in 2010. ‘I was immediately impressed by their desire to push the boundaries of autonomy in an architectural context,’ he recalls. Together they developed the concept of Flight Assembled Architecture, tested it at ETH, and then built the model as an installation at FRAC.

Gramazio and Kohler are professors at the ETH’s department of architecture, but the pair also has an award-winning architectural practice with a portfolio of realised projects, including a dance centre in Zurich, a public toilet in Ulster, a national pavilion in their home country of Switzerland and public-realm light installation.

Their work is about the pursuit of what they call ‘digital materiality’, which, according to Kohler, ‘connects data and material, programming and construction’. Because digital fabrication allows the architect to control the manufacturing process through design, Kohler says, ‘the material becomes informed’, while applying computational logic to construction ‘re-emphasises the meaning and expression of architectural design’.

The demonstration at Flight Assembled Architecture was more about structure than materiality. ‘Instead of “deep” surfaces or textures we would rather speak about “deep” structures that have a certain physicality and spatial sensuality’, says Kohler. Up the scale of their tower at FRAC to the Vertical Village and that spatial sensuality is evident.

From afar it might suggest a distorted, super-sized cooler tower. On closer inspection, each ‘brick’ is actually a three-storey building module, linked vertically where they overlap by cores carrying lifts and plant. Four bands of double, open decks planted with trees ring the structure to create a public realm and lateral circulation, and in some gaps arrays of wind turbines are mounted.

The design is both radical and highly sustainable, and the vision is to create an urban structure to house 30,000 people in rural Meuse, an hour from Paris by TGV.

But does Flight Assembled Architecture have applications in the real world? It has already demonstrated autonomous flight as a means of delivering materials. Kohler believes that even now there are lessons to be learned from elements such as the stacking logic and structural performance of the tower. D’Andrea notes that ‘by having powerful tools, we simply move the creative process to a different level. So, in particular, humans will be empowered to design and build things that simply could not be done without advanced automation’.

In September 2010, ETH established a research programme in Singapore called the Future Cities Laboratory, focusing on new material systems, robotic automation and fabrication processes, and digital high-rise design. As Kohler says, Flight Assembled Architecture shows ‘that the future has already begun, in the physical world and at real scale’. Images: Gramazio & Kohler and Raffaello D`Andrea in cooperation with ETH Zurich