I want to build a coop with a 10' x 10' dog kennel. I want to build a roosting box on the out side of this 8' long but only 2' wide and 4' high. I will put a roost 12" off floor. floor is 2' off of ground. roost will run 8' long ways. I want to keep dual purpose birds in this to 12 weeks of age. Not for eggs. Will this work? Is there enough room? Dont have much space to work with. Thanks.