It depends I spose how exposed you are as to what your ideal chicken shed would be constructed out of. We have massive winds here on the coast, we almost lost a 16"x10" shed full of tools last year to the winds, it was lifted and moved off the slab until we tied it down.
Our chicken shed is an old caravan chassis with builders ply sides, two broom handles for perches and 4 boxes for laying. We have ten chooks and they seem to like it fine.
We have also got 20 or so racket straps holding the netting pen to the floor cos when its windy - its windy!
As long as they have shelter, enough room, a few boxes and enough perching space for all them I dont think you can go wrong. The hardest thing I find about making stuff for the yard is that it doesnt have to be an exact design job, just do enough over engineering for it too last.
Ta
Baz