3D-printed housing cuts labour and concrete but faces CO2 challenge

3D printing could make construction more efficient and allow more varied building designs, but the technology does not automatically make concrete construction sustainable, DR reports. Professor Jon Spangenberg from DTU says 3D-printed construction is likely to become more common.

In Holstebro, a housing complex with 36 3D-printed student apartments has been built. The apartments measure between 38 and 50 square metres, making the project Europe’s largest 3D-printed building.

Fewer heavy lifts

3D concrete printing can potentially reduce the number of workers needed on a construction site. A robot is loaded with concrete and a digital drawing before building the walls layer by layer under computer control.

“Previously, people worked more manually. So there is potentially an increase in productivity,” Spangenberg says.

The technology could also improve working conditions by taking over heavy lifting and repetitive tasks that normally place strain on construction workers. A forecast from the Economic Council of the Labour Movement says Denmark will lack 99,000 skilled workers by 2030.

More freedom in design

Because the concrete is deposited in layers, 3D printing is less restricted to the square shapes common in much traditional construction. The method allows architects greater geometric freedom, Spangenberg says.

Traditional concrete construction uses large elements cast in moulds. With 3D printing, the shape can be much less constrained, allowing the machine to build the finished geometry layer by layer.

Less concrete can mean lower emissions

The freedom of form can also reduce the amount of concrete used in a structure. According to Spangenberg, cement production accounts for 7 to 8 per cent of global human-caused carbon dioxide emissions.

3DCP Group, the company behind the Holstebro project, says it used only 30 per cent of the material normally required for conventional construction with concrete elements. The technology could also eventually be used with more sustainable building materials.

Concrete remains a challenge

Using less concrete does not automatically make 3D-printed construction sustainable, Spangenberg says. Concrete still has a heavy carbon footprint, and the environmental impact depends on how the technology and materials are managed.

3DCP Group is among the companies experimenting with alternative materials for construction. Spangenberg says the Holstebro project could help encourage wider use of 3D-printing technology in the construction industry.