Round rooms adobe building ideas

Hello

I didn't find a topic on round rooms so i am starting one.
I planned an adobe home with 5 round rooms (bedroom, living room, kitchen, bathroom, connected with a corridor, and an entrance with a sun room to use for growing food and herbs in winter, in my area the adobe and rammed earth tectonics work best, i have been told by a contractor that the maximum diameter of my rooms should be 5 metres if i am planning to use local wood and no concrete at all for a flat roof.
Any ideas on different ways to place the limber for the roofing? any images of round rooms design? any precautions to take for openings (doors and windows, wardrobes)? i specially like openings (2m width windows) will that be possible with this design? any thoughts on the subject are welcome...
Thank you in advance

The flower house plan