Who hasn't always wanted a modern looking air conditioning unit on the roof of their villa or similar?

Instructions:

You build a "circle" out of light blocks (iron blocks or grey wool/clay) like on the main picture, stone steps at the edge and four normal rails in the middle. From this you can build "lines" of stone steps to different rooms, how you then integrate them in individual rooms is up to you, I took double stone steps to build it in the ceiling, for walls it is best to take oak steps with signs in front.