Why settle for a spherical room when you can have a spherical house? That is what Dr. Johann Ludowici thought in 1961 when he designed the Kugelhaus -
This German idea for handling the postwar housing shortage is admirable in its simplicity -
Of course, there is one small difficulty with this. True, the sphere is the most efficient way of enclosing a volume of space, but unfortunately, as you may have noticed, as a sphere tapers towards its base the amount of floor space reduces rather alarmingly, resulting in a globe home with the volume of caravan, but the foot room of a phone box.
Also, it is not advised to use the Kugelhaus on steep hillsides in earthquake zones. Otherwise, you could be woken up one morning at the start of a rather alarming, albeit brief, career.