Our's was a converted shed/outbuilding that was probably 12x20ish. It had a walk-in door for humans on the end. There was an attached/fenced yard of probably 20x20 feet in the front that they had free access to via their own little door. There was a gate/door on the pen as well and, most days, they were turned out to forage/eat bugs on the rest of our property. Inside was an open room with nesting boxes along one wall, a roost at the end opposite the door and a nice big floor space, feeders and waterers. There was electric, but no plumbing actually run to the building, but it was only about 50 yards from the house so it was easy enough to cart water, etc out there or run the hose for cleaning or what not.