More bad news for London housing delivery as new data reveals doubling of delivery timeframes

James Barton, Department Head Land Agency, said: “This data should be a serious wake-up call for politicians. It sheds light on the realities of development – increasing delays to planning and a dramatic fall in start-on-sites signals a new low for the market. This is compounded by the recent data on depressed construction starts, historically low new homes sales for the first half of the year and the fact that the GLA are on track to deliver less than 1,000 new affordable homes starts this year. 

“Simply put, it is non-sensical to keep ramping up tax and regulation and not expect significant unintended consequences. 

“The New London Plan is a good opportunity for a reset, but needs to also come with a realisation that strategic planning is redundant if private investors and developers don’t have the confidence to build. 

“There is still huge demand and need for more homes to be delivered in London, but the current system is not effective and too rigid, with local and central policy creating an environment that is simply too high risk for developers.”

The findings reveal a sharp rise in median lead-in times, driven by mounting regulatory and financial hurdles. Sites that began construction in 2024 took an average of 26 months from initial application, up from just over 17 months in 2015 and 13 months in 2013.

Though the time from initial application to a site gaining a resolution to grant full permission increased by a fifth since 2015, the data has been reasonably consistent. By comparison, over that same period, the time from resolution to full planning increased by 76%.

Oliver Knight, head of residential research at Knight Frank, said: “While much attention is paid to the time it takes to secure planning permission, our analysis shows that the post-permission phase – from resolution to full planning and then to site start – is where delays have grown most significantly. This is a period where a borough has resolved to allow development, but certain conditions or agreements might need to be finalised before official permission is issued.”

Time taken from securing full permission to starting on site has also increased, by 60% since 2015.

The number of new homes started annually in London has dropped by 77% over the past year compared to the market peak in 2015. In the first half of 2025, fewer than 2,200 new private homes were started according to Molior’s quarterly report – just 5% of the government’s target.

There has also been a significant hit on the demand side, as only 3,950 new homes were sold in the first half of 2025 according to Molior, the lowest level since 2010.

Knight added: “The key tool available to planners is flexibility, and a willingness to amend planning permissions and Section 106 agreements when problems arise. This will be vital if the supply of viable land for development is to be maintained.

“Removing the roadblocks that add risk and hinder viability should be the top priority of our politicians. While the Government’s efforts over the past year have laid some important groundwork for increased housing delivery, particularly reforms to planning policy, bold action is still needed.”

ENDS

Notes to editors

Knight Frank LLP is the leading independent global property consultancy, serving as our clients’ partners in property for 128 years. Headquartered in London, Knight Frank has more than 20,000 people operating from 600 offices across 50 territories. The Group advises clients ranging from individual owners and buyers to major developers, investors and corporate tenants. For further information about the Firm, please visit www.knightfrank.com.