3D Printers To Build Houses

gbjbaanb writes to point out an article in the Sunday Times describing two separate programs where robots are being developed to build houses. The Los Angeles project is farther along than the one in the UK, but the article provides more details on the techniques employed in the latter. Liquid concrete and gypsum will be sprayed from nozzles in a manner analogous to an inkjet printer. From the article: "The first prototype — a watertight shell of a two-story house built in 24 hours without a single builder on site — will be erected in California before April. The robots are rigged to a metal frame, enabling them to shuttle in three dimensions and assemble the structure of the house layer by layer. The sole foreman on site operates a computer programmed with the designer's plans... Inspired by the inkjet printer, the technology goes far beyond the techniques already used for prefabricated homes. 'This will remove all the limitations of traditional building,' said [an architect involved with the UK project]. 'Anything you can dream you can build.'"

Comments

Who puts in the rebar?

[Beryllium Sphere(tm)]

If there isn't reinforcement, how does the floor on the second story (first story for the UK project :-)) support itself? Is it arched or something?

How does it stay watertight? Do they just mean it will keep the rain off for long enough to get a real roof installed? Or are they planning on leaving it with a concrete roof?

What keeps the concrete from slumping while it's being sprayed? Does someone have to put up forms ahead of time?