Less than 5,000 new homes either for social or ‘affordable’ rent were built in London in 2016-17 (the latest year we have records for). Yet the Mayor’s latest assessment of housing need shows that more than 40,000 new homes are needed per year in London if we are to address London’s backlog of unmet need as well as newly arising need within ten years. This briefing sets out the figures, including a breakdown of which boroughs are performing best and which worst when it comes to developing new homes for social rent.