You do not normally require planning permission to install a heat pump. You can usually do the work under something called ‘permitted development’. This allows you to make small alterations to your home. In some cases these rights are curtailed and you will have to make a formal planning application.
What are permitted development rights?
Permitted development rights are generally small developments that you can make to your property without having to go through the formal planning process. Permitted development in England is governed by The Town and Country Planning (General Permitted Development (England) Order 2015.
In Wales permitted development rights are governed by a previous law called the General Permitted Development Order.
Installing a heat pump under permitted development rights
Since 2011 you have been able to install a heat pump on your property under permitted development rights. This means that you do not have to apply for formal planning permission to install a heat pump. There are some caveats to this right however, which we will explore below.
The size of your external unit
To install your heat pump under permitted development rights the size of your external unit (including the housing) must not exceed 0.6 cubic meters (1 cubic units in Wales). In Scotland it must be no more than 3 meters tall (2 meters in Northern Ireland).
How many heat pumps you want to install
You can only install one heat pump under permitted development rights. And only if there is no existing wind turbine within the curtilage of your property. If you want to install more than one heat pump you will require planning permission.
The position of the heat pump
You must situate your heat pump at least 1m away from the boundaries of your property under permitted development. Homeowners may install the external unit on a flat roof, but it must be at least 1m from the external edge of that roof. You cannot install the external unit on a pitched roof under permitted development.
You should install your outside heat pump in a way that minimises the effect on the appearance of your house and the surrounding area. This generally involves place it out of the way at the side or at the back of your home that respects the amenity of the area. It should generally be at the level of the ground storey unless you’re installing it on a flat roof.
The type of heat pump
You can only install your heat pump under permitted development rights if it complies with the Microgeneration Certification Scheme Planning Standards (MCS 020) or equivalent. The MCS Foundation, which is the main trade body for heat pump installers in the UK, developed these set of standards. They govern things like noise levels and placement of the heat pump. If you’re really geeky you can read the mcs planning standards here.
Where permitted development rights do not apply
There are certain areas where permitted development rights are curtailed, or do not apply at all. Generally speaking these will include the following:
- Conservation areas
- Areas of Outstanding Natural Beauty
- National Parks
- the Broads
- sites near a scheduled monument
- World Heritage site
The laws around what is and isn’t permitted development in these areas is quite complicated. If your property is in any of the above we strongly advise you to ask your local planning authority whether ashp installation is allowed under permitted development. If it is not, you will need to make a formal planning application.
Article 4 direction
In addition, a local authority can remove permitted development rights by means of an article 4 direction. This is essentially an area where the local planning authority say that permitted development rights do not apply. It is often not a formal conservation area.
If you live in an article 4 area you may need formal planning permission to install a heat pump. Again we urge you to check with the local planning authorities.
Heat pump installation in a listed property
If you live in a listed building you will almost certainly require consent for a ground source, or air source heat pump installation. Listed building consent is quite complicated and you should consult with a heritage expert. There is more information on this at the Historic England site.
Installing a heat pump under planning permission
If you live in an area without automatic permitted development rights to install a heat pump, do not worry. You may still be able to do the installation. It is a bit more complicated, and will involve having to make a planning permission application to the local council, but it is not the end of the world. We would advise you to enlist the help of a planning consultant or architect. The good news is that local authorities do want to encourage zero-carbon technologies and, in our experience, do tend to look favourably on these kind of applications.