For more than a century, architects have dreamed of building houses the way we build cars or ships. But the reality of construction today is a far cry from Le Corbusier’s idea of a ‘living machine’ based on standardisation and mass production. Concrete is still poured into wooden moulds on site, blueprints are still printed on paper and the drywall builder still waits for the electrician to finish. The efficiency and rationalisation once associated with industrialised construction remain elusive. Now, however, the old idea seems to be reforming under digital conditions – automated, centrally controlled and offering unprecedented design freedom. At least that’s the promise often made in connection with 3D printing: ‘Europe’s largest 3D house, built in just 140 hours’, Tagesschau (20.07.23); ‘A house, six apartments and 118 hours of printing time’, Handelsblatt (28.12.24). For those who believe in the potential of 3D printing in architecture, building a house no longer takes months or even years, but just a few days. But how does 3D printing actually work?

Additive vs. Conventional

While early methods such as stereolithography have been used in industry since the 1980s, 3D printing developed much later. Essentially, 3D printing falls into the category of ‘additive manufacturing’, where components or entire buildings are built up on site, layer by layer, from a viscous material. Depending on the method and application, this material can be based on a range of substances – including concrete, sand, plastic, metal or recycled materials such as waste paper.

In house printing, a specially developed liquid concrete is often used, which is applied to the foundation slab using a printing arm. A computer-controlled nozzle deposits the material along a digitally pre-programmed path, forming walls, partitions or components – all without the need for formwork. The process is guided by a 3D model that defines each step of the printing process. Unlike traditional construction, there is no need for complex formwork or manual intermediate steps. The process is automated, accurate and relatively fast.

More Form, Less Material

This technology-assisted production makes it possible to manufacture components with high dimensional accuracy and complex geometries, which would be difficult or even impossible to achieve using conventional methods. At the same time, it saves material because material is only used where it’s structurally or functionally necessary. In the context of the circular economy, 3D printing plays a key role – additive manufacturing means that only the actual amount of material needed for the component is used. There’s no off-cut waste, no discarded moulds. The mould is flexible, the process is efficient and printing can be done around the clock if required. Even complex shapes such as ribbed structures or honeycomb patterns can be produced with optimum material utilisation – something that is almost impossible to achieve with conventional construction techniques. 3D printing not only advances the principles of industrial construction – automation, rationalisation, prefabrication – but also enhances them through digital control and greater creative freedom. Two recent projects illustrate both the potential and the current limitations of 3D printing in construction.

Europe’s Largest Print Projects

The data centre building for Heidelberg iT Management GmbH & Co. KG is one of the largest 3D printed buildings in Europe: the shell of the approximately 50 metre long, single-storey building was completed in just 170 hours. Thanks to digital control and on-site fabrication, many traditional steps such as formwork or intensive manual labour were eliminated. At the same time, less material was used because the concrete was precisely extruded layer by layer. The project demonstrates the potential of 3D printing for functional, medium-sized buildings with individual design languages – but also highlights current challenges: the undulating structure of the building placed high demands on the roof design, certified windows for the new type of printed concrete were not available, and full completion still took more than ten months, despite the rapid construction of the shell. In addition, the large size of current printers makes urban applications difficult.