Ok, I'm new to chicken raising and have 15 light brahma hens for egglaying. I want to build a permanent coop for them to winter in..I live in Maine, USA. I have read that standard sized chickens need 3-4 square feet per bird. I'm not the best at figuring out what that translates to in dimension..such as 4' x 6' or 8' x 10', etc. Can anyone help me figure on the best size coop for my 15 girls? I want them to have an outdoor run available in warm months but they will be kept inside during winter. Also, would 4-5 nest boxes be enough for 15 hens? Any help in designing and building a coop that will keep my girls happy and healthy will be appreciated! Thank you!