In this situation prefab concrete would be a significantly...

In this situation prefab concrete would be a significantly better solution. What they did produce was a few pieces of wall that have been used between windows and doors to create "the house" where even Fred Flintstone would complain about how the walls look.
Printing in 3D is a great technology suitable for many different applications especially where complex shapes are required but it is inherently slow, these 4 pieces of wall probably took over 4-5 days to print, and later still had to cure.

I think that FBR have a much better solution to the house building but in my opinion this is a lifestyle company.

There is another Adelaide based company AL3 trying to progress the 3D printing in metal on larger scale and their technology is impressive but a look at their share price history shows that it's hard to get any traction.