I feel that this is enough detail (at least I hope it is).
I need to decide what the 'boxes' (on the ground level) are going to be, I need a firm idea if I am going to texture them!
Looking at this I should make the railings thinner.
I plan on unwrapping this onto 2 x 512, although since I am unsure how much stacking (placing UV shells on top of each other, in order to make more space on the unwrap) I will be doing, I will unwrap the building as a whole, then split that unwrap into 2.
This will take a long time.