Yes, it's a greenhouse. I built it a couple years ago. Here's a picture of it as I'm standing on my roof. As you can see we do gardening and kids over here.
The cost of building my dream coop has me considering other options.
One idea is sectioning off a back corner of the shop that came with house as a coop. For future resale I'd want to protect the existing floor and walls by building up a wood floor and covering the lower 3-4 feet of the walls...
