Installing an Air Source Heat Pump in a Listed Building
We all love the fact that the UK is such an historic nation – but that can cause us a few problems when it comes to updating certain homes.
If you live in an old, listed or historically interesting building you probably already know you can’t just start knocking walls down and re-doing the windows.
Well, the same applies to the heating you want to use.
If you want to upgrade your heating system from an old fossil fuel boiler to a modern air or ground source heat pump, you may run into some problems.
You maybe think ‘Why would I put an air source heat pump in an old building, they don’t work, do they?’ But that all depends on your building.
There’s an 11th century church in Leicester that fitted an air source heat pump a few years ago and it’s been very practical.
Read about it here - St Egelwin the Martyr Church.
Or, carry on reading this blog to find out all about installing an air source heat pump in a listed building.
How Do Air Source Heat Pumps Work?
Simply put, ASHPs work like a backwards fridge.
They take air from the outside and use it raise the temperature of a low boiling point refrigerant liquid.
Once the liquid is at a slightly warmer temperature that it’s natural state, it is put under pressure and forced through valves.
This heats it up even more, to the point it can be used to heat water in a tank.
That water is distributed into your heating system, either in the radiators or for your hot water needs like the bathroom and kitchen.
We look into it in more depth here.
Getting Permission for your Air Source Heat Pump
The average home in the UK doesn’t need any planning permission to fit an air source heat pump – they probably don't for a ground source one either.
But, if you home is listed, in an area of outstanding beauty or somewhere that has certain restrictions, then you are going to have to get the council involved – which is never an easy ask.
This can add untold delays to the process, which is not ideal if your fossil fuel boiler has just gone pop.
The truth is, most ASHP installations will get the go ahead from the planning dept if the work done isn’t too destructive and the look of the actual building isn’t affected.
The most visual part of an air source heat pump is the outdoor fan unit – so make sure your put that somewhere out of the way.
Anything you do must comply with conditions listed on the UK Planning Portal website. Wildlife is another consideration you will have to investigate.
Bats, birds, water voles, great crested newts and other protected species are all likely to affect a planning application.
On top of that complying with Building Regulations, and guidance set out in the Approved Documents, will be a priority for any home improvements.
Things to consider when installing an ASHP
The good thing about installing an air source heat pumps is there are no ground works to consider.
Obviously ground and water source heat pumps are a different matter.
So, all you need to bear in mind for AHPS is the visual impact of the outdoor condenser, or fan, unit.
You can’t hide these away in a box or shelter though, as they need to have unrestricted air flow around them and, to be honest, they are not the prettiest of things.
Some manufacturers will offer colour changes to the units to make them blend in, but this will incur extra cost.
Some people will put them in plant rooms or outhouses, which isn’t ideal but can be a work around.
Remember, the compressor/fan part of the ASHP system does make a noise.
It’s usually under 40 dB but it is something you need to be aware of.
Heating Systems
Another consideration you may need to bear in mind is the way you are distributing the heat from ASHP.
A lot of the time, the existing radiators and towel rails you have in your home will be adequate for your needs but, occasionally, you mat need to swap out some radiators for bigger ones.
Not a problem unless your radiators are part of the listed building’s look.
If you can’t change the radiators, you may, bizarrely, be able to fit underfloor heating.
Although this is obviously a much more intrusive and destructive way to retrofit a heating system, once it has been done, it will be hidden so your home will look exactly as it should.
Things to look out for when fitting an ASHP on a listed building
To give you an idea of what is expected of you if you fit an air source heat pump with the permitted development rights – or in a ‘normal’ home – we’ve compiled this list:
• Bear in mind it’s only permitted development if there are no wind turbines on or within the curtilage of the property.
• You may only fit one air source heat pump on or within the curtilage of any building with is attached to another building – unless it’s flats.
• You can fit two air source heat pumps on or within the curtilage of a detached dwelling.
• The external fan must be limited to 1.5 cubic meters on or within the curtilage of a dwellinghouse, or 0.6 cubic meters on or within a block of flats.
• If you are in a World Heritage Site, or a conservation area, your heat pump must not be visible from the road.
• If you don’t live in a World Heritage Site, or a conservation area, your heat pump can be visible from the road but must be installed on the ground floor storey and not above.
• If, for some reason, you’ve fitted the fan on a flat roof, it must be set back at least 1m from the edge of the roof; it cannot be installed on a pitched roof.
The curtilage is an area of land around a house and forming one enclosure with it.
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