What are the planning permission rules for installing an air source heat pump?
Heat pumps, powered by increasingly green electricity, are central to decarbonising home heating.
The UK installed 69,000 heat pumps in 2022 – it needs to install 10 times that in 2028 to be on track to meet the government’s targets.
There are a number of ways to help speed up heat pump adoption. For example, bringing down the cost of installation and running costs. But even when homeowners are committed to making the switch to low-carbon heating, other obstacles, including planning regulations, can still prove challenging.
Why are heat pumps subject to planning regulations?
When installing an air source heat pump in a home, many factors need to be considered, including planning rules. Across Great Britain, residential air source heat pumps fall under permitted development rights. This means they can be installed without planning permission, as long as they meet certain conditions. These conditions vary depending on whether the home is in England, Wales or Scotland.
Where planning permission is required for installing a heat pump in the UK it will be to address risks related to the impact of sound, the visual aspect of the tech, and how it fits in the space. This is particularly the case in densely populated areas and conservation zones. It can also apply to listed buildings where permitted development rights do not apply.
In the UK, environmental health regulations apply broadly to all sound-generating equipment. This includes heating systems. These regulations give local authorities the power to investigate sound complaints.
How noisy is a street of heat pumps?
Research into sound complaints about heat pumps shows they are rarely a source of significant concern. A study of Freedom of Information (FOI) requests found that 124 councils reported no sound complaints between 2020 and 2023, while only 42 councils recorded a single complaint each.
A modelling study commissioned by Nesta and undertaken by Apex Acoustics investigated the impact of cumulative heat pumps on sound levels in dense residential areas. The report found that there was no audible increase in sound levels from multiple heat pumps. Essentially, having more than one heat pump running in the same street would not audibly increase sound levels.
The Aurora II - 10kW has a maxiumum sound pressure level of 52 dB(A) at the source. The maximum sound pressure at 1 meter is 43 dB(A) when in an open field (O) and 46 dB(A) when placed near a wall (M).
What is the MCS 020 sound limit?
MCS 020 is a UK technical standard under the Microgeneration Certification Scheme (MCS). It regulates sound levels from air source heat pump installations. It sets a maximum allowable sound level of 37 decibels at the nearest neighbouring window. It also provides guidelines for measuring and managing sound. To qualify as permitted development – and not require planning permission – heat pump installations must comply with MCS 020. Heat pump installers will check the planned location of a heat pump meets the sound limit before moving ahead with installation.
What are permitted development rights?
In many cases, a heat pump can be installed without needing planning permission, as part of permitted development rights. This is conditional on certain criteria being met.
Permitted development rights criteria include:
- compliance with the MCS 020 sound limit
- no other air source heat pumps or wind turbines present on the property
- the heat pump not being situated on a pitched roof
- the volume of the heat pump’s outdoor unit not exceeding 1.5 cubic metres (1 cubic metre in Wales). In Scotland there is a height limit of 3 metres.
- the heat pump not being installed on any wall above the level of the ground floor if that wall fronts a highway
- the property not being a listed building
- if the property is in a conservation area, that the heat pump is not installed on a wall or roof that fronts a highway.
What are permitted development rights?
In many cases, a heat pump can be installed without needing planning permission, as part of permitted development rights. This is conditional on certain criteria being met.
Permitted development rights criteria include:
- compliance with the MCS 020 noise limit
- no other air source heat pumps or wind turbines present on the property
- the heat pump not being situated on a pitched roof
- the volume of the heat pump’s outdoor unit not exceeding 1.5 cubic metres (1 cubic metre in Wales). In Scotland there is a height limit of 3 metres.
- the heat pump not being installed on any wall above the level of the ground floor if that wall fronts a highway
- the property not being a listed building
- if the property is in a conservation area, that the heat pump is not installed on a wall or roof that fronts a highway.
The Aurora II - 10kW has a maxiumum sound pressure level of 52 dB(A) at the source. The maximum sound pressure at 1 meter is 43 dB(A) when in an open field (O) and 46 dB(A) when placed near a wall (M).
What is the MCS 020 noise limit?
MCS 020 is a UK technical standard under the Microgeneration Certification Scheme (MCS). It regulates noise levels from air source heat pump installations. It sets a maximum allowable noise level of 37 decibels at the nearest neighbouring window. It also provides guidelines for measuring and managing noise. To qualify as permitted development – and not require planning permission – heat pump installations must comply with MCS 020. Heat pump installers will check the planned location of a heat pump meets the noise limit before moving ahead with installation.
Planning rules differ across Great Britain
Permitted development rights and planning rules differ across England, Wales and Scotland. This is because planning is devolved from Westminster to the Welsh and Scottish Governments.
Reform for planning restrictions
This poses challenges for consumers and installers operating across multiple regions. If heat pump planning rules were aligned, this could create a more cohesive and streamlined approach to the deployment of air source heat pumps. Read more about this in Delivering clean heat: a policy plan.
Explore the map to see planning rules for England, Wales and Scotland.
The planning obstacle
In the majority of cases, permitted development rights allow homeowners to install heat pumps without needing planning permission. However, planning requirements can still pose significant barriers for some households.
Our diagram below shows how complex the journey can be – adding time and costs to the installation.
Nesta has called for an alignment of air source heat pump permitted development rules across the UK. It has asked for the UK Government to work with the Scottish and Welsh Governments. The aim would be to align planning rules across England, Wales, and Scotland so they are less complex to navigate.
Where to go for further information and advice
For homes in England and Wales, more information is available on the Planning Portal.
Many homeowners can install air source heat pumps without requiring planning permission, but when they do need planning permission, the complex, costly and length process can be a barrier to heat pump adoption. Meanwhile, gas boilers are more damaging for the environment.
Arranging for a gas boiler to be installed is relatively straightforward, with a streamlined, quick process.
If a heat pump doesn’t require planning permission, that can again be relatively straightforward – although it is a lengthier and more complex process than getting a gas boiler.
For heat pump installations that require planning permission, the journey can become even more prolonged, painful and expensive. And that is if permission is granted.
Where permission is denied, this adds more obstacles to the installation process. Throughout the planning process there are barriers which could see homeowners not progressing with the installation.
The planning obstacle
In the majority of cases, permitted development rights allow homeowners to install heat pumps without needing planning permission. However, planning requirements can still pose significant barriers for some households.
Gas boilers
While more damaging for the environment, arranging for a gas boiler installation is relatively straightforward, streamlined and quick process.
Heat pumps
If a heat pump doesn’t require planning permission, this can be relatively straightforward – although it is a lengthier and more complex process than getting a gas boiler.
For heat pump installations that require planning permission, the journey can become even more prolonged, painful and expensive. And that is if permission is granted.
Where permission is denied, this adds more obstacles to the installation process. Throughout the planning process there are barriers which could see homeowners not progressing with the installation.
Nesta has called for an alignment of air source heat pump permitted development rules across the UK. It has asked for the UK government to work with the Scottish and Welsh governments. The aim would be to align planning rules across England, Wales, and Scotland so they are less complex to navigate.
Where to go for further information and advice
For homes in England and Wales, more information is available on the Planning Portal.
Conclusion
Even though many homes meet permitted development criteria, there is room to improve planning rules. This would enable even more homes to transition to low-carbon heating with ease. More work is needed to be done to explore if certain approved sound mitigation measures could help households to meet the sound limit. This would enable more homes to meet the limit and avoid going through planning.
If you're working in this area we'd be interested in speaking to you, so do get in touch below.
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