I have two coops. I don't think they're what you're looking for, but I'll post them just in case.
My first coop (and the one I now use as a nursery for raising chicks) was a playhouse for children that I bought 1/2 price at Lowes. I got the idea here on BYC. It has 16' feet of floor space - a little small - but it comfortably housed my 6 barred rock hens.
ETA: the cost for this was about $300....but it was $500 if you add the price of the dog run we added.
All I did to the playhouse was:
- put hardware cloth on the windows to keep out predators
- I put it up on stilts so the food and water could go underneath and be protected from rain.
- Nailed plywood covered with linoleum to the bottom to make a floor (don't mess with the 12x12 squares...use one continuous piece.
Here it is:
Now, the problem was: I liked the six hens SO much I wanted more!!! So we converted this "shed" that the previous owner left behind into a coop. It's 9'x9' and even if we'd built it ourselves, it would have cost under $200. It's no beauty, but it works!