Rules for siting heat pumps and heat pump planning permission

Planning for heat pumps: an introduction

In most cases heat pumps for residential property don't require formal planning permission as they are considered a permitted development. However, permitted development itself has some caveats that must be observed and planning permission will be required if your property is a listed building, in a conservation area or world heritage site.  

It is also important to be aware of the clearance requirements that different kinds of heat pumps typically stipulate to ensure safety, efficient operation and the avoidance of any noise nuisance.

Permitted development rights for air source heat pumps

Permitted development rights are designed to make heat pump installations on domestic premises safe and avoid visual and noise nuisances for surrounding properties. Heat pump installations fall under Class G permitted development guidelines.

Provided your property is not subject to any special planning permission such as listed building consent and is not in a world heritage site or designated conservation area then you can install a single heat pump on or within the curtliage so long as the installation of the heat pump complies with MCS planning standards. 

The MCS planning standards stipulate that air source heat pump installations should meet the following criteria:

• Have a noise level at or below 42 decibels
• In England and Scotland the external unit must be installed at least one metre from the property boundary, whilst in Wales it must be more than 3 metres, whilst in Northern Ireland the heat pump must be 30 metres or more from he nearest house. 
• Be for heating purposes only
• Installation on a pitched roof is not permitted development. If installed on a flat roof all parts of the air source heat pump must be at least one metre from the external edge of that roof.
• The air source heat pump unit must not be installed on a wall if that wall fronts a highway and any part of that wall is above the level of the ground storey.
• The installation can only be within 1 metre of a maximum of 3 reflective surfaces including the ground, walls, windows etc. For example, an air source heat pump unit installed within a small light well where it was less than a metre from the walls or windows on three sides and within a metre of the ground would not meet mcs planning standards. 
• There are also some limitations on the size of the external compressor unit. The limits and dimensions vary dependent whether you are in England, Scotland Wales or Northern Ireland, so you should check the current rules dependent on your location. 

Note that permitted development covers only a heat pump OR a wind turbine on a property. If you want to install a heat pump but already have an existing wind turbine, you will need planning permission. 

It is also worth noting that there is, at the time of writing, consultation ongoing on the relaxation of several of these rules including the 1 metre boundary rule and the sizes of an external unit, so it is worth confirming the latest status of guidance from your local authority before proceeding with your installation. 

Permitted development rights for ground source heat pumps

As they are usually installed indoors a ground source unit installed with the curtilage of a house or block of flats is usually exempt from any specific restrictions on permitted development. However there are some restrictions that apply:

• As for air source heat pumps, only one pump can be installed under permitted developments rights.
• When no longer needed for microgeneration pumps should be removed as soon as reasonably practicable and the land should, as far as reasonably practicable, be restored to its condition before the development took place, or to the condition agreed in writing between the local planning authority and the developer.
• The total area of excavation for ground works must not exceed 0.5 hectares.

Air source heat pump planning permission

Even if your property meets the criteria for permitted development if a property is listed, in a site designated as a scheduled monument or is subject to other special measures to preserve its historic interest or environs, you may still require planning permission.

As of July 2024 new guidance from English heritage has been issued that makes this less likely, though you should always confirm this with your local planning authority before proceeding. The Energy Efficiency and Retrofit in Historic Buildings guidance now states only that:

"Listed building consent is normally required for the installation of heat pumps which are fixed to a building"

As this guidance is new and relatively untried at the time of writing you are still strongly advised to confirm any requirements for planning permission with your local authority conservation officers. There may still be a preference that the external unit of an air source heat pump be installed in such a way as to minimise impact on the external appearance of the property and different local authorities may interpret the new guidance in different ways.

It is also worth taking note other elements of your heating system than the boiler may also be subject to protections. There may be very rare exceptions where the existing heating system, or components of it, has architectural or historic significance (for example, original cast-iron radiators).

Most installers will be happy to assist with obtaining planning permission. 

Ground source heat pump planning permission

Although indoor units are themselves usually exempt from planning permission, any disturbance to the landscape in a world heritage site, conservation area or within the curtilage of a listed property caused by earthworks for ground loops or boreholes, or the erection of any outbuildings for the accommodation of plant may require planning permission. 

Informing your electricity network operator about your air or ground source installation

You or your installer must inform your local District Network Operator (DNO) if you intend to install a heat pump.

Your DNO, which is a different body to your electricity supplier, will confirm whether there is sufficient electrical capacity in your area to allow for the heat pump to work without interfering with the electricity supply to your neighbours. 

This is usually a formality, and is a requirement of an MCS (Microgeneration Certification Scheme)  approved installation if you are receiving a government grant,  but is worth doing before the installation as you can be forced to remove your heat pump if you install a heat pump system without notifying your DNO in advance. 

Additional consents required for an open source water source heat pump

If you plan to extract water from the sea, a river or stream, canal or ground water for use in an open loop water source heat pump, you must have a license for extraction and discharge. 

Installations must have an extraction license from the Environment Agency and/ or Canal and Rivers Trust for any extraction above 20 metres cubed per day.