A network of organic 3D-printed concrete columns makes up Tor Alva, a 30-metre-high tower modelled on a cake, unveiled yesterday in a small mountain village in Switzerland.
Created by cultural foundation Nova Fundaziun Origen in collaboration with professors from the university ETH Zurich, the tower is intended to revive Mulegns – a village currently home to 11 people.
According to the team, it is the tallest 3D-printed tower in the world. After five years in Mulegns, it will be dismantled and rebuilt elsewhere.
Tor Alva, or White Tower, was built on an existing building formerly used as a blacksmith's shop. It was revealed yesterday for the first time, after a cover concealing it was removed by a helicopter.
Its four-storey form was prefabricated and is intended to emulate a layered cake, paying homage to the history of confectioners in the region, while blending into its mountainous backdrop.
"The form of the structure is reminiscent of an ornate layered cake – a reference to the emigration history of confectioners from Graubünden who exported their skills from here to the whole of Europe," said the team.
Tor Alva was developed by architect Michael Hansmeyer and ETH Zurich professors Walter Kaufmann, Robert Flatt and Benjamin Dillenburger, alongside the university's spin-off company Mesh and construction firm Zindel United.
It is constructed from 3D-printed concrete components that double as load-bearing elements, printed by ETH Zurich at its Hönggerberg campus over five months, before being transported to the site.
The concrete components were created by robots in "an additive manufacturing process", meaning the concrete was applied layer by layer and reinforced with steel rings, negating the need for formwork.
Each component is connected without adhesives, using removable screws and post-tensioning cables to ensure the structure can be easily dismantled and rebuilt elsewhere in the future. A spiral staircase connects each level.
The columns were prefabricated. "While one robot applies the concrete in layers, a second places a ring-shaped reinforcement in the new structure every 20 centimetres," explained the team. "This horizontal reinforcement in the form of rings is supplemented by longitudinal rebars that are added after printing."
To ensure the concrete could support this layering process, professor Flatt developed a specific concrete mix that hardens quickly. "Just before the concrete leaves the pressurised nozzle, two additives are blended into the mixture, allowing the characteristic droplet-like relief on the columns to be achieved," said the team
"The White Tower is more than a technical triumph – it inspires the building sector, encourages sustainable tourism and offers new cultural space," concluded Nova Fundaziun Origen founder Giovanni Netzer.
