[NeBob]

We built our bus bay 20' by 60' with 14 x14 doors on each end. Also included a sewer dump and 50 amp service. I think the bay is just right. Gives you room to work on each end and sides. The bay was poured at 6 inches thick with rebar reinforcement. In the center is a floor drain which I find very functional.  Our unit does not have slides but would accommodate them. Hope this helps
Bob and Gerri