I am in full swing of building my new coop almost completely by myself, I am very proud. The walls are up and sheeted, the windows are hung. The floor will be replaceable, but is Advantex that will be painted. (Advantex has a 50 year guarantee against swelling and rotting, someone we know has had some in a bucket with water for 2 years and still has not swelled). It will be 10x20 right next to my 6x6 coop. I am planning on expanding my pen to 20x30 feet, but will have a partition in the pen with a door that can be opened so I can divide it in half when/if needed. Most of the materials are being recycled from collecting bits and pieces all summer. It will even have vinyl siding which is costing me nothing. I want to put a section for supplies (bedding, feed, cleaning tools, etc.) and then have an area permanently designated as a brooder and nursery. I currently only have 7 guineas that are 18 weeks old and 2 cockerels and 2 pullets that range in age from 20 to 40 weeks. Would you build a permanent "infirmery" area for sick/injured birds in the coop as well, or just use a 24x48 inch wire dog kennel for that purpose that can be put up and taken down as needed in the coop? How large would you recommend the brooder/nursery area? My brooder in the house was 4x4 feet and my nursery area in the coop this summer was 3x6 by 5 feet tall. I do not have power running out there right now, but I have 2 100' outdoor extension cords that can be run as needed. Any other suggestions of things you wish you had done differently when you built your coops?