Starting to sway towards a concrete one now. Looking at a 34'3" x 24'6". Not as big as what I was first thinking about, but big enough for the extra space I need really. If I need extra space inside to work on anything I can always move a couple of cars outside.

I'd fuck the garden off completely in favour of one big industrial unit if I had my way, but I wouldn't get away with that. Think this will be a good compromise.