I put a sprinkler system in my Md house, It was the common "split foyer" design you see a lot up there and the thought of a fire in the utility room under the stairs scared the hell out of me. That is a choke point for he whole house. I slept better with a wet pipe system that had heads in the utility room, the downstais hall (below the upstairs hall to the bedrooms) and on the stairs. It was really a fairly small amount of pipe with 5 heads but it did wet down the choke points.
