I wired all the components to the side and insulated the whole thing in 3 1/2 inch batt insulation, trying to get as good a seal as possible with the vapor barrier. I closed it in with 1/2 inch plywood and then painted it with Behr Premium Plus Ultra, which is water based but extremtly durable and mildew resistant (if you believe the packaging). Before pulling through the wires, I put the control panel over the spot it would be and drilled the holes. Once the paint was dry, I pulled the wires through and secured the box with lag screws. I installed the buses and ground bar and got to work on the wiring.