Sadiq Khan today promised to crack down on mega-basements in London as analysis showed applications increased by 66 per cent in five years.
Labour’s mayoral candidate said he would tighten planning laws to limit the size of extensions and give neighbours greater protection from disruption.
The basements have become increasingly popular in some of London’s most expensive neighbourhoods as homeowners attempt to increase living space without infringing planning controls.
Recent extensions which have caused controversy include Damien Hirst’s plans in Regent’s Park and one road in Chelsea where six mega-basements are being constructed at the same time.
The figures, obtained through Freedom of Information requests, show that applications are up by two thirds in the 12 inner London boroughs since 2010, from 2,552 to 4,228. Wandsworth saw the biggest increase, of 159 per cent.
Many neighbours worry that the excavations could damage their foundations.
Mr Khan said: “As Mayor, I’ll act to give greater protection to residents. I’ll amend the London Plan to limit the size of so-called mega-basement extensions, and give neighbours greater protection from the noise, dust and disruption major works on this scale can cause to households and communities.”
Last year, Islington unveiled guidance which will limit extensions to double the “footprint” of the original building or 50 per cent of the garden — whichever is smaller — and resist applications of more than a storey.
