A Knightsbridge house could be tripled in size by drilling that goes 50 feet underground.
But the neighbours of the homeowner who wants to do this has aren't too happy, as Marcus Powell reports.
More top news
His top speed is believed to be the highest ever recorded in the UK by a rider carrying a pillion passenger.
The mayor took time out from City Hall to join Conservative party workers handing out leaflets in Uxbridge and South Ruislip.
No matter where you look, London's population is getting older - with the exception of one of the capital's boroughs.