a reply to: SpartanKingLeonidas
It's very nice, i'll take it!
Cheapest and most efficient way to build an UG home, is to pick a gently sloping site, like a natural hillock, hire a digger (JCB etc), dig a large
circular trench to the depth you want your home to be at, let's say 15 feet or so deep and make the trench a couple of meters wide in a ringed
circle...the dirt removed from the trench is piled up in the centre of ring, building an earthen dome shape who's top is just above the ground
Next, lay a combination of thick plastic sheeting / bitumen sheeting over the earthen dome, and then lay sheets of metal / re-bar / heavy gauge wire
over the plastic and bitumen...then pour concrete over the entire earthen dome, better still an easier way is to spray the concrete on.
Make the concrete as thick as you like, but i'd go for at least a foot thick all over...when set hard, the concrete creates a solid dome, the top of
which is just above the ground level.
Next, dig out all of the earth that was taken from the trench and used to make the dome, and you're left with an empty, free standing concrete dome
(as large as you decided to make it).
The earth you removed from under the concrete is then piled up on top of the concrete dome, and grassed or planted over.
A central skylight in the top centre of the dome could be added for natural light if desired.
The entrance is dug from below and slopes away with the natural slope of the land (to avoid flooding entering the dome) and the floor under the dome
can then be dug and poured, and internal walls and divisions can be installed in the concrete dome. (extra rooms can dug beneath the floor of the dome
The beauty of this method of UG construction is its relative simplicity and speed of construction. And stable temperatures all year round, which
eliminates much of the costs to heat and cool and property.