Of course it is more expensive by far to build this way but why not build a house that can withstand a fire so at least the underground part of your house survives the fire. Using Rebar and cement you could separate the above ground floors from the below ground floors in some way so the fire cannot travel into the house below the surface of the ground.
In this way people wouldn't ever become homeless from fires.
However, if you are doing this in a flood plain this isn't going to work at all in a flood.
But, if you are on a hill in a forest this might work out fine.
By God's Grace
