My 2mm workbench is currently occupied by a 15mm model of a bedroom with en-suite for my daughter's techno project. All the doors and drawers need to open, but fortunately the plumbing need not work. I (supposed to be she, but who's kidding) have completed the toilet, bath and vanity unit, while she built a desk and chair.
I've had to use a good proportion of my stash of plastikard and foamboard (what would have been loads for 2mm goes nowhere in 15mm) and my 0.3mm wire is going to make doorhandles and taps.
Apart from the waste in materials has been the manhours. Oh what could have been achieved if I had been able to spend a whole weekend on 2mm stuff.