Adopting the Parisian example of low-rise developments would enable another half a million homes to be built in London without the need to use green belt land, according to the Campaign to Protect Rural England.
There is enough airspace over existing one- and two-storey buildings for that number of homes, the group said in a report.
It also calls on local authorities to require all suitable brownfield sites to be developed before any protected greenfield land is built on.
