I am only getting 3 Hens right now. 3 Rhode Island Reds 26 weeks old so they should be laying soon. The coop i built is a converted rabbit hutch it is two stories the top is 3' x 5' and the bottom is 3' x 8 ' the bottom level is open floored so that grass and dirt are available. It has some open sections(chicken wire covered of course) (2 sides are closed with plywood) I planned on covering the open long side with a tarp to prevent drafts and only leaving the small 3' left side open for ventalation. I plan on having the 3 hens wander around my big fenced in back yard when i am home (Neighbors on both sides have cats). Now for the questions. Will the one side being covered in a tarp be enough to keep the 3 warm? I have some heat lamps from when i raised some baby ducks could i use them as suplemental heat( lamp would be shining in the open side and be in the weather)? What temperature would they need suplemental heat added(I live in Indianapolis so it gets a bit cold)? How long does it take to imprint the homing instinct so that I can let the new birds out of the coop? When the birds range my fenced in back yard would it be futile to seed my back yard for grass?