Only one third of new homes needed in London were built in 2014, according to analysis by the National Housing Federation.
More than 37,500 more houses needed to be built to keep up with demand.
David Orr, the Chief Executive of the National Housing Federation said there was an easy but slow way out of the housing crisis.
He said there was plenty of land and potential investors looking to build new homes in London - and it was time to act.
The unlicensed events unfolded on Saturday night at Clapham Common and Tooting Bec Common.
A 37 year old man who was taken to hospital after getting into difficulty in a stretch of water near Maidenhead has died.
Jonty Bravery, who is mentally ill, has been jailed for 15 years after throwing a six year old boy from the Tate modern balcony.