We are talking nightclub, yes?
If I remember correctly, Lakota does not have steps from the front door to the main club area, however I am not sure how wide the doors are etc but I think there are toilets on that floor too.
www.lakota.co.uk/clubspec.htm
Also, Trinity is mainly on one level though I think there are stairs to a chill out area but loos etc are on ground floor.
Lots of clubs I can think of have steps (up or down) from the entrance to the club (Odyssey, Lizard Lounge, Po Na Na, Thekla, Carling Academy etc etc).
HTH