It may still be sci-fi for some, but 3D printing is fast breaking down conventional barriers in engineering and architecture and changing the way the construction industry operates. Last month, Milan showcased the first 3D-printed house in Europe to be built almost entirely by a robot. Ike Ijeh reports

17_©Arup_Giorgio Giunta

Source: Arup / Giorigo Giunta

The one-storey showcase prototype – which takes just 48 hours to build – has been erected in front of Milan cathedral

Over the past few years the race to build the world’s first 3D-printed house has morphed from specialist sci-fi sideshow into one of the most compelling technological contests within the mainstream building industry. First off the blocks was Shanghai-based engineering company WinSun with its 3D-printed villa and flats in China’s Jiangsu Province in 2015. The five-storey, 1,100m² main building claimed to be the first 3D-printed block of flats in the world. 

Next came the world’s first 3D-printed office in Dubai in 2016, again designed by WinSun in a collaboration with Gensler UK engineers Thornton Tomasetti and opened by none less than the prime minister of the United Arab Emirates. The single-storey 250m² structure was built in only 17 days and required a team of just seven installers and 10 specialist electricians to put together. 


The CyBe robot is not static like those on most 3D-printed schemes, but sits on caterpillar tracks to allow greater flexibility and variation

Europe’s first micro-home followed in Amsterdam in 2016, an 8m², 25m³ gabled cabin designed by Dutch practice DUS Architects. 2017 saw Europe’s first 3D-printed house, a 37m² one-bedroom structure in Moscow that was constructed using a mobile printing crane in just 24 hours. Designed by Russia and San Francisco-based 3D-printing specialists ApisCor, it cost just over £8,000 to build. And now Western Europe’s first 3D-printed house, 3D Housing 05, has opened in Milan. 

Debuting last month at Milan’s design festival Salone del Mobile, the one-storey, 100m² showcase prototype has been built in a prestigious location in the piazza right in front of Milan’s famous cathedral and was unveiled by the city’s mayor. 

Designed by Arup and Milanese architecture practice CLS Architetti, it embraces many of the same technological advances of its predecessors: it can be dismantled and relocated, takes just 48 hours to build and therefore represents significant cost and programme savings when compared with the construction of traditional housing.

3_©Arup_Luca Orlandini

Source: Arup / Luca Orlandini

Once the wall modules are in place, human workers insert windows, doors and internal fittings

Paradigm shift

For Guglielmo Carra, Europe materials consulting lead at Arup, the advantages of 3D-printed technology are clear. “The construction industry is one of the world’s biggest users of resources and emitters of CO2. We want to bring a paradigm shift in the way the construction industry operates and believe that 3D printing technology is critical to making buildings more sustainable and efficient. It creates less waste during construction and materials can be repurposed and reused at the end of their life.”

3D Housing 05 was built by a 3D-printed robot, which was supplied by Dutch 3D-printed concrete specialist CyBe. The robot squeezes out concrete through a nozzle and this forms the principal wall structure for the house. This wall structure comprises 35 concrete modules, each one taking just an hour to build. Windows, doors and roof are then inserted by construction workers as soon as the concrete is dried. The concrete mix itself is not conventional and is manufactured using a mixture of cement and additives specially primed for their unique method of application. 

As finished, 3D Housing 05 contains a living area, bedroom, kitchen and bathroom and displays a quality of internal finish that is pleasingly domestic in character and does not give away the fact that the building was essentially constructed by computer. 

Significantly, the house also features curved walls. While these were a feature on Russia’s 2017 3D-printed house, the Milan version applies curvatures over a larger scale. Their presence is also an important factor in challenging popular perceptions of 3D-printing technology offering the limited flexibility of orthogonal construction. 


Source: Arup

The 3D-printed robot squeezes a specially formulated concrete through a nozzle to form the 35 wall elements that comprise the house

Digital approach

For Luca Stabile, Arup Italy’s building practice leader, the 3D-printing technology that 3D Housing 05 harnesses is a sign of things to come: “3D printing will contribute to breaking the conventional barriers in engineering and architecture. The use of new technologies alongside a new digital approach to the built environment will be instrumental to creating even more complex multi-storey 3D printed buildings,” he says. 

But Stabile touches on a partnership that some see as fundamental to the success – or otherwise – of 3D printing technology: digitisation. And this in turn reveals the final significant development that differentiates 3D Housing 05 from other similar examples in the increasingly crowded 3D-printed housing market: it was constructed almost entirely by a robot rather than humans. 

Most 3D-printed buildings and all 3D-printed housing that predated 3D Housing 05 were built by a static 3D printer. Although this would invariably have swivel or rotating functionality, it would ordinarily remain fixed to the same spot throughout the build and would thereby be limited by the logistical restrictions this would entail. However, the CyBe machine the Milan project makes use of is known as a robotic manipulator. This is a robot attached to a movable base which therefore offers significantly increased flexibility in terms of construction process and greater variation in terms of finished building form. 

The particular robot in question is called the CyBe 3Dp and it claims to be the world’s first 3D concrete printer that can move on caterpillar tracks. It can print at a higher speed of 600mm per second and has an extended printed range that can build up to 4.5m in height. The robot is wifi controlled via specialist software and costs well over £300,000. It is also capable of building fixtures and fittings such as ironmongery and furniture. 

7_©Arup_Luca Orlandini

Source: Arup / Luca Orlandini

The curved walls of 3D Housing 05 challenge perceptions of 3D printing as offering a limited style of construction

Robots integral to 3D-printing

Digital design specialist Nick Grace is a former CAD specialist at Arup and the former head of Rapidform, the Royal College of Arts’ 3D-printing unit. He has now established his own digital design consultancy and for him, 3D-printing technology, despite all the futuristic clamour that surrounds it, will be all but redundant unless it goes hand in hand with the committed utilisation of robotics. 

“The future has to be 3D printing and robotics working together, that’s the way 3D printing can utilise additive and subtractive systems as well as assembly. There’s no point using 3D printing if you’re simply going to automate the traditional construction process.”

Accordingly, Grace believes that more could be done to fully integrate robotics into the future construction of 3D-printed buildings. “The Dubai 3D-printed office printed individual panels, but then the printer had to stop so that workmen could come along and add reinforcement in the traditional way. In the same way, the Milan project, which I believe just uses robots to build the walls and not the entire structure, is an incremental step rather than a revolutionary one.” 

Grace continues: “If Singapore’s Control Robotic Intelligence group can develop robots that can now easily assemble Ikea flat-pack furniture for demonstration videos, then those are the kind of applications that need to happen with 3D-printed buildings in order to truly maximise efficiency.”

Milan’s 3D Housing 05 undoubtedly represents a radical step into the future of 3D-printed buildings. Its proponents envisage the technology being applied to larger projects and have suggested that it could be deployed on scenarios where speed of construction and cost effectiveness are paramount, such as disaster relief or emergency housing. But it also offers an insight into a world where robots play an ever-increasing role and presents challenging questions not only as to how humans and robots will coexist in the construction industry of the future but whether 3D-printing technology will deem human manual labour necessary at all. 

Project Team

Engineer: Arup

Architect: CLS Architetti

3D-printing robot supplier: CyBe Construction 

Concrete supplier and consultant: Italcementi