An analysis of UK planning permission applications and outcomes by the research and innovation foundation Nesta suggests that from 2015 to 2026, households across Great Britain have spent up to £8 million on heat pump planning permission applications, despite an overwhelming majority being approved.

Roughly a third of households installing a heat pump are affected by planning rules, which usually delay the process by weeks and occasionally months.

As part of its work assessing what barriers consumers face when making the switch, Nesta built a custom in-house AI tool to access nearly 20,000 online planning permission applications in England, Wales and Scotland and analysed their outcomes.

The data suggests that roughly £3-4 million has been spent on residential planning applications for heat pumps, with a further £2-4 million spent on specialist sound assessments over the last ten years. But the overwhelming majority of these applications are approved (over 80%) including for listed buildings or those in protected areas, which do not automatically qualify for permitted development rights (PDR).

The government has announced a summer consultation to explore changes to permitted development rights to make it easier for households to install a heat pump. Nesta suggests that extending permitted development rights to Grade II listed buildings would help thousands of applications clear through the system more quickly and at a lower cost. In addition, developing a cheaper alternative to the expensive BS4142 sound tests could be a way to lower costs for heat pump applicants. For example, installers in France use a web app developed by the French Heat Pump Association to predict sound levels at no extra cost.

Katy King, director of Nesta’s sustainable future mission, says:

“A significant proportion of people who want to get a heat pump are being forced to spend their valuable money and time on lengthy planning processes. Most applications are approved, so this raises questions about whether some people have wasted time and money having to go through the process and whether it can be streamlined to only require applications where they are absolutely necessary. The government could extend permitted development rights, revisit the need for in person sound assessments and waive application costs so that people aren’t put off unnecessarily when making the switch from fossil fuel heating. This would save consumers time and money, while ultimately accelerating UK home decarbonisation.”

One heat pump owner, Fay, had to submit planning permission for her installation. She said:

“The application process was tedious and when submitting my application, I didn’t know how long it would take to go through, so that was a worry. If I hadn’t been able to do it myself then I probably wouldn’t have bothered getting a heat pump as the additional cost of engaging someone to do the application for me would have put me off. It should be easier for people to install them.”

For the 11,550 residential planning applications where the heat pump was a factor in the decision of the planning application being rejected, sound was the most common reason (43%), followed by a lack of design information (36%) and appearance (36%). The least common reasons were highways (3%), ecology (3%) and boundary rules (7%). A quarter of refused applications included a public objection.

More than 2,000 applications included a specific mention of a BS4142 sound assessment, the UK’s standard measurement to assess the impact of sound on nearby areas. Almost all (91%) applications with a passed sound assessment are approved, while about 35% of applications are approved, 33% are refused and 28% are withdrawn when the test is originally failed. These tests cost between £1,000 and £2,000, adding an estimated £2-4 million on professional sound assessments between 2015-2026.

Applications for buildings with some form of special designation were also approved most of the time (80%). Of those that were refused, 25% were in conservation areas and 2% were in an Area of Outstanding Natural Beauty (2%). A smaller share of refusals are in Article 4 designation areas (2%), World Heritage sites (0.5%) or National Parks (0.3%). Of the 2,106 applications for buildings with some form of listed status, 80% of applications were approved.