Affordable home ownership is at its lowest for 30 years with house prices now eight times higher than the average salary.

The UK’s planning system has been seen as the culprit of this crisis, reducing housing supply and causing a huge shortage of homes for the growing population.

Academics from the University of Warwick analysed 18 million planning applications and have pinpointed new evidence on the UK’s planning system.

Their research shows that planning refusals aren’t the problem, and the attention they get is somewhat misguided. Over the past decade, refusal rates for new housing units were almost half the rate than the previous 10 years.

It is the bigger projects which have become more significant. Large projects of over 50 housing units now represent two thirds of newly permitted developments, with very large projects of over 500 units representing 38% of new developments. Twenty-five years ago, these very large developments only made up 8% of new housing.

These bigger developments are much less likely to be refused planning permission than smaller developments. The evidence shows that a single unit project is twice as likely to be refused planning as one with over 500 houses. However, these bigger projects face far more hurdles, delays, red tape and paperwork than smaller ones. Many of these hurdles set in only once permission is granted.

It takes an average of 4.5 years for the planning process to be completed for very large developments, and in some cases can take over 11 years. This suggests that the Labour government’s focus on building new towns to meet the 1.5 million home pledge may mean these new homes do not materialise very quickly.

The research identifies five possible reasons for delays from case study evidence.

1. Financial contributions to the local area: A developer responsible for a 7000-unit estate in Bedfordshire was required to contribute almost £80m for local infrastructure (schools, roads, community facilities and transit services) and unexpected costs.
2. Infrastructure delays: The new development of Northstowe in Cambridgeshire was left in limbo for around 4 years due to a delay in the Highways England-led expansion of the A14, which the new town was entirely dependent on.
3. Regulatory barriers: The Eastern Green development in Coventry was required to comply with seven environmental regulations including sustainable drainage systems and flood risk management.
4. Council led delays: In Ebbsfleet Valley, a new town near London, the planning process for 43,000 houses started in 1996. Delays to decision making and resubmissions has meant that work did not start until 11 years later in 2007. To date only 4000 of the 43,000 houses have been built.
5. Community opposition: The Eastern Green development received over 300 pages of local objections and 173 letters in opposition were filed. The first outline application was made in 2018 and the land remains undeveloped as of 2024.

Nikhil Datta, Assistant Professor in the Department of Economics at the University of Warwick and co-lead on the project said:

“Our research has shown that there are many often unrelated barriers which impact on the housing supply, and it is not simply planning refusal rates which are the problem. The UK government needs to consider this when setting and implementing policies. Not only is new housing hampered by the planning process itself, but regulatory barriers, infrastructure setbacks and community opposition all play a part. We will be investigating these factors further to quantify their relative importance.”

Amrita Kulka, Assistant Professor in the Department of Economics at the University of Warwick and co-lead on the project said:

“If the UK is to meet housing delivery targets within shorter timelines, addressing planning delays is essential. Our research highlights a shift since the early 2000s towards a greater reliance on large-scale developments for housing supply. Such developments take substantially longer to go through the planning system than projects of smaller sizes. To speed up housing delivery, the government should consider a mix of small and medium-sized developments, alongside urban extensions and new neighbourhoods.”

Neil Jefferson, Chief Executive, Home Builders Federation said:

“As this important research demonstrates, there are a number of significant barriers to successfully bringing forward large sites, within a realistic time frame. Policy makers need to create a framework within which sites of all sizes can come forward more efficiently if we are to meet communities’ housing needs and allow builders of all sizes to increase output.

“Whilst the new Government’s speedy interventions on planning are welcome, there is no silver bullet and further interventions on the supply and demand side will be required. Amidst a dearth of affordable mortgage lending more support for buyers is required to provide the necessary confidence in demand that allows industry to invest. Building the homes we need will deliver both the social change and economic growth the new Government needs but will take commitment across a range of policy areas.”

• Read the briefing: Five facts on the UK planning system
• The UK planning system - Technical Appendix

About the authors:

• Amrita Kulka is an Assistant Professor in the Department of Economics at the University of Warwick
• Nikhil Datta is an Assistant Professor in the Department of Economics at the University of Warwick and a fellow at the Centre for Economic Performance, LSE.
• Edoardo Badii is a PhD student in the Department of Economics at the University of Warwick.
• Johannes Brinkmann is a PhD student in the Department of Economics at the University of Warwick.