A German software engineer has invented a process that will put up a nine-storey residential building, with 54 apartments and a gross floor area of just under 4200sq m, in about three months.

And Gropyus AG’s co-founder and chief technical officer Philipp Erler has the building to prove it.

In March last year the Vienna-based company completed its nine-storey prototype—variously known as “Gropyus Building #00001” and “Im Wohnpark Nette 6”—on the banks of the river Nette, about 15km from Koblenz in Germany’s west.