underground house construction

I designed a underground house several years ago and the brief was to be simple to construct by normal contractors in the building industry. The sketch below shows how it works. There is two ways to construct the house first pore the Top slab as if it were going to be a suspended slab but with footing at the edges. Make sure that the bottom of the slab is pored onto form that is to be seen later in the build.

When the slab has cured the earth is dug from under it with a bobcat or dozer.  The spoils are placed directly onto the slab and it is only moved once.  The side walls are left with the natural batter and there is no way the slab can fall down as it is sitting on its own footings.

I got the sketch a bit wrong as the next slab (Middle) is formed and pored as the first with its own footings the same as the first slab.
The third slab as is done as  above.  Any inward movement is stopped by the compression of the slabs on its edges. Spoon drains are placed at the edges of the slabs.  Dry wall is used to divide the spaces as required and the area behind the dry wall is used for services. That is plumbing electrical  phone and music etc. The batter is sprayed with paint to stabilise the batter.  Remember that you only have to glue in the key stone which  may be a grain of sand..

The second way to build is to excavate then  build suspended slabs on formwork and there is working at heights which will cost more and the hire of the formwork which is another expence. The dirt has to be moved twice as well. I personally like the first way myself.

The image below shows the basic design. Another way to build is to dump a load of sand on the ground and pore concrete over the sand and then dig the sand out, walla a dome.

As  there is only a slab of concrete on the ground  you might not need council approval just for a slab of concrete. If you use these ideas it is up to you to make sure that the work is done safely,remember they are only ideas.

If you have any questions put them in comments and I will endevor to answer them for you