Looks like a really cool project
We had a roomate one time who brought home two adult chickens (the reason why now escapes me, but it was stupid I do remember that ). Anyhow, after keeping them in the crawlspace for about 2 weeks and not being able to bear the smell, we had them "taken care of" and boy were they delicious
So I can attest to the smell thing, good thing you are making a coop.
Joey