bigfoot and northern lite details on their construction

I now own a Northern Lite , at one time I owned a Real Lite had a side door and jack knife couch, and it was a four season camper it had copper shut off valves to cut the water off to the outside shower. Surprised that Northern Lite and Bigfoot neither one has a valve to cut water off to the outside shower, when it is below freezing I would think the valves on the hot and cold water side might freeze?