It's CC-licenced, so any print shop could do it. Even Staples. I use netprinter.co.uk for printing plans.
It looks gorgeous on A0. I almost want to get one done on flimsy paper so I can have trouble folding it, but that's a little too close to Martian rambler cosplay.
No current plans to print and sell copies, this one was for a competition prize in the Times. Fingers crossed they will reconsider.