When it comes to pre fab unfortunately it's all about cost. There are some incredibly expensive better quality coops that I can't really bash but for the cost I feel I could build a whole barn myself. So the cheaper you find, the more you may as well light the money on fire it's just so temporary. Especially with 11. What they advertise is just not true. The super cheapo's on Amazon might work as a brooder but no chance for adult chickens. SO better use of your money is modifying something like a shed. I just got a shed from Lowe's for my son's house and the whole time we were assembling it, I was thinking this would be such a great coop. When I started with a flock of 6 I modified a dog house. I'm not a carpenter, I'm in IT. But if I can do it, you can too! But for 11, I think you're looking at slight mods to a shed. OR money is no issue and you're going after a quality coop for 11 chickens, like Carolina Coops (just an example, I know nothing about them,) around 5k. Have you checked out the Coops section of BYC for ideas?