The London property market could receive a significant boost following Mayor Sir Sadiq Khan’s announcement to ‘actively explore’ building on parts of the green belt.

The controversial move marks a major shift in stance for Khan, who has previously opposed development on protected land.

Sarah Hiscutt, Partner in Planning at Knight Frank (pictured), has welcomed the move, saying: “Sir Sadiq Khan’s commitment to build on green belt land represents a significant and necessary step forward in addressing London’s housing crisis.

“At Knight Frank, we have long advocated for a balanced approach to green belt policy. A review of poorly performing undeveloped green belt land would serve to identify even greater opportunity beyond previously developed sites.”

Current system unsustainable

The mayor argues that, with many Londoners unable to rent or buy a home, the current rules prohibiting development on the green belt are ‘wrong, out-of-date and simply unsustainable. ’

Under the new proposals, London’s planners will be able to consider releasing some stretches of green belt land, but with conditions attached relating to the provision of affordable housing, energy efficiency, transport links and promoting access to green spaces.

Khan’s announcement comes as London struggles to meet its ambitious housebuilding target of 88,000 new homes a year, with current brownfield sites delivering less than half that at 40,000 and the mayor acknowledging that ‘this alone will not be enough to meet our needs.’

According to Knight Frank‘s recent Residential Development Land Index, although greenfield land values have edged lower, housebuilders are facing persistent cost inflation and planning uncertainty. The firm argues that opening up the planning process would help mitigate those higher costs.

Strategic green belt release would enable greater scope for suburban expansion.”

Hiscutt says: “Strategic green belt release would enable greater scope for suburban expansion, supporting the provision of family housing where it’s most needed and where supporting infrastructure is viable and can be efficiently extended.”

She adds. “What’s essential now is establishing criteria for identifying appropriate sites and ensuring developments deliver substantial affordable housing, strong transport links, and enhanced public access to truly valuable green spaces.”

The plans have also received support from Deputy Prime Minister Angela Rayner, who called it a ‘bold proposal’ that ‘rises to the challenge of tackling London’s housing crisis.’

However, there is strong opposition from Conservative politicians and environmental groups. Andrew Boff from the London Conservatives described the move as a ‘complete betrayal’ of previous pledges to protect the green belt, while countryside charity CPRE pointed out there are currently 300,000 unbuilt planning permissions.