Hi Mutt Farm!
That's great to hear that your playhouse served well until you went with larger flock.
I'm maxed out with 8 birds. I really don't want more because they're my pet and I can't even keep up with their egg production since my husband and I don't eat too many eggs. My neighbors enjoy our free organic eggs more than we do. I know that chickens are pretty hardy, but I still want them as comfortable as possible. I noticed mine would all hang out in the coop on very cold/windy days (only few days here in TN), so I even added a panel heater to their current coop which they love. I spy on them with my security cameras
I've looked around and for $400-$600 there aren't too many options, and I don't like most of the designs where chickens have to walk through roost area to reach nest boxes with their poopy feet.
I wanted to consider plastic coop this time around because I noticed wet wood becomes moldy that's hazardous, and it can rain nonstop during spring here in TN.
I'm sure I'll find out soon enough, but were the plastic walls ok to work with when you added your roosts?
I planned to build mine on a platform as a raised coop. There are some really cute designs online. Light weight, zero maintenance, easy to disinfect. That would give your girls an additional 12+ sq ft underneath the coop to stay shady and dry. And you don't have to crawl in to get eggs. You could hang the boxes on the outside with a hinged lid too. Rain? Oh, now I remember, is that the wet stuff that fell from the sky here a few years ago?
I agree with the wood in the TN rain being a maintenance consideration. The prefab in your budget are by most accounts worthless and flimsy at best. For the roosts, I used a shovel handle, and the -u- shaped thingies they use to hold pipes to walls and self tapping screws with a drop of rubber cement. The plastic walls were challenging. I'd build a free standing atop the nest boxes with a poop board if I need to use it again (chicken math, broody house) You'll be a bit tight with 8, but if they are getting along now and you're going bigger. Waiting for updates!
ETA: I'd really thing hard about adding heat. Folks rarely do that even in below zero climates. There are some great threads about it
Edited by Mutt Farm - 9/29/15 at 1:16pm