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Do Grant heat pumps need planning permission?
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Do Grant heat pumps need planning permission?
Thanks to their compact size and design, the Aerona³ heat pump gives installers, specifiers and their customers one less thing to worry about when working to meet the permitted development requirements.

When making any significant changes to a property, it is important to know whether or not planning permission is required. Here, Kevin Ellis, Grant UK’s Renewables Sales Manager, explains why most Grant heat pump installations do not need planning permission and while this blog is primarily aimed for installers and specifiers, the content will also be of interest to homeowners.

The installation of an air source heat pump is considered permitted development if certain conditions are met. In Section G of the Town and Country Planning (General Permitted Development) (Amendment) (England) Order 2011, there are a set of criteria that must be fulfilled and while the list may appear long, many properties will meet these conditions. Attention therefore then turns to the heat pump unit itself and whether that complies with permitted development.

Location, siting and listed properties
With air source heat pumps being external units, it goes without saying that much thought and care should be taken when deciding where to position the unit. Not only should the heat pump be sited so as to maximise its performance but other factors need to be considered, some of which may determine whether or not an installation falls within permitted development. There are instances whereby planning permission will be needed and these include:

  • If a heat pump is being installed at a listed building or on a site designated as a scheduled monument
  • If a heat pump is being installed within 1m of the boundary of the curtilage of a dwelling house or block of flats
  • If a heat pump is being installed on a flat roof within 1m of the external edge of the roof or on a pitched roof.

There are other conditions, including those which specifically relate to properties within conservation areas or World Heritage Sites, so there are certain circumstances whereby planning permission will be required. It is also worth noting that if more than one air source heat pump is being installed, or a heat pump and a wind turbine are being installed on the same building, planning permission is needed.

However, for a typical home looking to reduce its carbon footprint, the above conditions will not be relevant so permitted development remains open as long as the heat pump and the installation itself comply to key conditions.

Heat pump volume
One of the conditions that must be met to comply with permitted development relates to the size of a heat pump’s outdoor compressor unit. The volume of the outdoor compressor unit, including housing, must not exceed 0.6 cubic metres – if it is larger, planning permission will need to be obtained and for some heat pump makes and models, their volume exceeds this limit so are not eligible for permitted development. The good news is that all of Grant’s air source heat pumps meet this requirement - their units are less than 0.6 cubic metres so this particular requirement for permitted development is automatically satisfied.

MCS Standards
The heat pump installation must also comply with MCS Planning Standards - Microgeneration Installation Standard MCS 020 - a copy of which can be downloaded here. Part of this installation standard relates to sound levels, specifically the sound level calculated at an assessment position adjacent to the nearest doors or windows of the neighbouring building. If a sound level of 42dB(A) or less is calculated, the installation will meet this condition for permitted development. The method for making this sound assessment is detailed in the MCS 020 Standard and forms part of MCS installation practices so, for those installations completed through our G-Cert Scheme, Grant UK can help installers with this calculation.

In summary
The installation of a Grant air source heat pump falls within permitted development subject to specific site conditions being met. Thanks to their compact size and design, the Aerona³ heat pump gives installers, specifiers and their customers one less thing to worry about when working to meet the permitted development requirements. To review all the requirements needed to work within the realms of permitted development, it is always recommended to check with the Local Authority Planning Department.

Kevin Ellis
Renewable Sales Manager at Grant UK