Everyone knows that there are choppy times ahead for the British economy, as uncertainty over just what Brexit means continues until terms sheets are drawn up with the rest of Europe and the world.

Icebergs; Mega-basements; Batcaves; There's no shortage of shouty opinions on London's basement bonanza.

In the wake of recent high-profile cases involving a property on Grosvenor Street in Mayfair, the former Stock Exchange building in Manchester and land near the Magna Carta memorial in Surrey, Nick Martyn…