I have a Ware Chick-N-Hutch that is now too small for my flock. So, I want to add an external Ware nestbox that I just bought to the side of it. The problem is Ware markets these for their "Premium" coops and not the hutch. In my nestbox package, there weren't any dimensions for cutting a hole for the nestbox. Does anyone have a premium Ware coop that could tell me the dimensions of the opening for the external nextbox?