[DungeonMaster]

So, rebuild the foundations. The houses, unless they have collapsed, should be sound enough to withstand the house being jacked up and for the foundation to be rebuilt in place of the old one.

Yes. Have you seen what they are doing in London with the multi-million dollar 3 floor basements? There's a 50ish minute youtube video about it.

[Oratam]

It’s going on in NY as well. A five story townhouse with a 3 level basement. Where else can a billionaire have his gym, pool, rock climbing wall, garage, wine cellar, movie theatre, etc.?