German contractor Züblin and technology firm Instatiq are testing the boundaries of 3D printing by printing the top floor of a four-storey apartment building on site in the small city of Metzingen, 30km south of Stuttgart.
The team is using Instatiq’s P1 concrete printer with a 26m-long, pre-programmed boom arm to print 3m-high load-bearing walls, laying up to 2.5 cu m an hour.
“We use it to build the load-bearing walls of the storey in just four days,” said Chris Brandstätt, Züblin’s group leader for process planning.
“One cubic meter of printed solid wall requires only half the time of conventional limestone masonry construction, as used on the other floors. This not only saves us time, but is also our response to the ever-increasing shortage of skilled workers. And our employees benefit from better working conditions with less dust and noise.”
‘Bringing progress to the region’
Developer GWG Reutlingen is building three apartment buildings with a combined 44 units at the site. Its technical manager, Florian Bertz, said the alternative approach to this storey was about “bringing progress to the region”.
“With the 3D concrete printing project in Metzingen, we want to consciously test alternative construction methods – resource-saving, efficient and future-oriented,” he said.
“For us, this is a strong signal: we are ready to take responsibility for the future of construction.”
No special deliveries
Instatiq chief financial officer Fabian Schüler said the printer uses concrete from a conventional mixer.
“This means that no special building materials have to be delivered over long distances,” he said.
“The financial savings are obvious. At the same time, the machine fits perfectly into the work processes on the construction site and has an enormous reach with its 26-meter-long, automatically controlled boom arm.
The three apartment buildings are scheduled for completion in May 2026.
Züblin said it and Instatiq were planning more projects in a joint venture called Nelcon, subject to antitrust approvals.
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