Building work once done by human hands can now be done by machines. That, as Jonathan Glancey explains, opens up new possibilities for architects.

In a workshop south-east of Stuttgart’s city centre, builders can fly. Here, programmed by students at Stuttgart University’s Institute for Computational Design (ICD), drones buzz around like purposeful bees, fetching and carrying long threads of carbon fibre spun by a robot in the middle of the room. Bit by bit, and without the help of a single human hand, the drones shape these strands into a structure.

The workshop is run by Achim Menges, a German architect and the founder of the ICD. He is at the forefront of the rapidly evolving field of robotic architecture, in which robots make not only the components of buildings but also assemble the buildings themselves. This approach offers two advantages. The first is that it saves money and time. This year in Vienna, Coop Himmelblau, an Austrian architectural firm, will use robots to help build a new hotel tower, the machines lifting and welding the panels that form the building’s exterior into place. Wolf D. Prix, the architect behind the project, estimates that robots could reduce construction times and manpower by as much as 90%, which gives architects more freedom to create.

In California, Ron Culver and Joseph Sarafian have developed an unlikely method of making intricate structures out of concrete using robots and Lycra. Traditionally, concrete is formed using hard moulds; for each different shape you want to generate you need a different mould. But in Culver’s and Sarafian’s system, the concrete is poured into Lycra sacks stretched by robotic arms into any number of different shapes. Once set, the pieces are bound together using 3D-printed joints. The technique allows them to add complexity without cost.

The second advantage is that robots open up entirely new methods of design and fabrication. In Zurich, Matthias Kohler and Fabio Gramazio, who in October 2016 opened a new robotics laboratory, have been demonstrating how cheap, recyclable structures can be built from low-grade material without mortar or adhesive of any kind. Their Rock Print project, developed with the Self-Assembly Lab at the Massachusetts Institute of Technology, is a tower of glass pebbles held together by nothing more than thread woven by a robot. The machine, guided by an algorithm, lays down the thread in a pattern so precise it would be unachievable by hand, over which the pebbles are then poured. This is repeated layer by layer until a tower emerges, bound together by nothing but string. Its structural integrity has more in common with lasagne than with a conventional building. It’s a process that might one day be used to build quickly in emergencies.

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