Asked by: Megan Jackson, Age 9, Abergavenny
It’s already happening! Scaled-up 3D printers that use concrete instead of plastic filament have been used to build wall sections for several years. And in 2016, Huashang Tengda (a Chinese construction firm) 3D printed an entire two-storey house. The steel reinforcing bars were still installed by hand, but then a concrete extruding robot printed the walls around them in just 45 days.
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.