Hi, I am in the process of designing my coop and run. I have 6 RIRs and may be getting 6 Australorps. Will a coop that is 4'x6' (24sqft = 2sqft per chicken) be big enough, or should we try and build a 6'x6' (36sqft) or 6'x8' (48 sqft). My mom wants to build a 6x8'. The run area that my parents are planning is 10x10' = 100sqft. However, right now it is a raised area (2x4"s around it) with flat concrete blocks on the bottom, with grass and weeds growing between them. My parent's weren't sure if we should leave it that way or put dirt or sand, or both on top of the cement blocks? Any advice? And would this size run be big enough for 12 chickens? We figured this would be a good area for the run because no predators could get in from the bottom. They will be free ranging too in my fenced backyard when we are home. Thanks in advance.