Square foot question

[LadyBug7]

We built a coop using Ana White's plans http://ana-white.com/2012/05/plans/frame-chicken-coop but changed the floor of the loft. We only covered half of it, leaving a roost space. So my question is, when you figure the necessary square footage, does it include roost space? I'm worried that if it's too cold and they don't leave the loft, they might not have a lot of space. I hope this makes sense, I don't really know how to explain what I'm thinking.

 

[petrel]

I think the coop square footage is just considered as that space in which they can move about, but remain out of the weather. Roosts are usually above the measurable floor space.