I want a circular gathering hall th...

I want a circular gathering hall that is 15 x 15 in diameter. Primarily using any variation of stone brick, cobbled deep slate, dark oak and spruce but all blocks are welcome I want the building to be 22 blocks high with the first floor being a gathering hall and roughly 8 blocks high. the second floor being six blocks high and containing three rooms. A third room will be in the beginning of the roof area and will be four blocks high and obviously tapered because it is part of the roof