If you build the dome tall enough it isn't really an issue. My dome is a 20' diameter 5/8 dome and my head will only touch if I am standing 4" away from the wall.

Each of the 15 sides is around 4' long on a 20' dome so you can put square furniture against the side if it isn't over 4' long. It is a problem with long furniture. I have an 8' long counter and I drop stuff behind it all the time.