INDUSTRY continues to find multiple uses for 3D printing, especially in rapid prototyping and for high-value, low-volume production in businesses such as aerospace. But one of the limiting factors is the size of the 3D printer itself: objects need to fit inside the machine to be built up layer-by-layer. Now some 3D printing systems are moving, so to speak, out of the box. That way they can be scaled up and used by the construction industry to print buildings and other structures.

To print the bridge, the robots will either sit on it, printing their own support structure as they go, or operate from barges moored on the canal below. Either way, the process is likely to take about three months. The project is being supported by Autodesk, an American producer of design and engineering software; Heijmans, a Dutch construction firm; and ABB, a Swiss-based maker of industrial robots.

The use of 3D printing in construction is “no longer a novelty” in providing customised interior-decoration features, lighting effects and furniture, according to a recent report by Lux Research, a Boston consultancy. Interest is growing in printing large structural parts or even entire buildings because of the opportunities to save construction time and achieve a greater flexibility in design, the report found. But challenges remain, in particular developing printable construction materials and meeting building codes.

Winsun, a Chinese company, has built a number of 3D-printed houses, including a five-storey apartment building. It uses a six-metre-high 3D printer to ooze a fast-drying paste made from a mixture of cement and recycled waste from construction sites. Under computer control, the giant machine deposits the paste layer-by-layer to create walls and other prefabricated sections of the building. These parts are then joined together at the construction site using steel reinforcing bars.

NASA is not alone in thinking that 3D printing may be the only practical way to build beyond the Earth. Foster + Partners, a London firm of architects, is working with the European Space Agency on a different system. It would use a rocket to transport to the Moon a tubular module that would unfurl to provide a domed support over which a robotic 3D printer would fabricate a protective shell using lunar material.