They are just paying to have more space in their home really. How much would that above ground space costs, say if they had to go lateral? About as much as it costs to go sub ter. It is Hamspted, this is what happens.
As for it being a post SHTF bunker, not really. The world knows about it and look at where the people are from. If I wanted to hide a bunker and recruit a private army to defend me, I bet I would have a much better chance in Nigeria rather than a top end suburb of one of the major world capitals.
What made me laugh was:
Lady Listowel Wrote:It is sad that there is a row over the application as everyone usually gets on around here.
These sorts of basements are being built all over Hampstead, but it's a conservation area and it's not in keeping with the street.
Nothing to stop people getting on due to things happening below the street. You put up with the building works and spoil removal the time it takes. Conservation areas are nothing to do with what happens below ground. The streetscape has nothing to do with the subterranean, but if they are being built all over the place, then sure they are in keeping.