Chicken math is already getting me. We are building our coop this weekend and I know we need to build it bigger than originally planned cuz now I want some silkies too! Maybe a silkie roo too! so starting with 8 red pullets and then knowing I will want to add more chickens... I need at the very least 40-50sq ft of coop.. right? Can I make separate rooms in it and keep adding on ? plan on a little tikes playhouse raised off the ground and also enclose the space underneath it too with a floor. i have a fenced in backyard that is plenty big. We will let them out when we are home to keep an eye on them. Building the coop and run inside the fence. I want happy girls.