The first idea is catenary reinforcing -- the red wires are catenary lines and render the building self-supporting with no (or very little) additional reinforcing needed. The black wires are additional beams required by code and common sense -- these can be minimal and help allow for non-catenary reinforcing and more flexible design.

The second idea -- pre-fabricated, arched triangle, roof panels. 12 -18 feet wide. On the ground you build arched triangles in a dish shape. Finish the inside of the dish, flip the dish over, set with a crane and this becomes the ceiling of the dwelling. No overhead plastering. A row of tiles inside, finishes interior ceiling.

Building triangular dishes -- start with insulation then structural layer and then polish the inside of the dish. THE HARD PART -- Turn the dish over and stack it in vertical pile until the crane comes to set 8 dishes. Crane --reality check-- for these dishes on the first floor I'd say 4 hours at $150 per hour is $600-- or $75 for each of 8 panels. Set the dishes and stick them together in the valleys -- formwork very simple using plaster lath -- mix this pour on site, (pour out of a 5 gallon bucket) and vibrate from above. 1/2 yard should go a long way.

How to best support the dishes when moving them so they don't crack??? This idea works for domes too.