EPC is based on cost of energy use for the dwelling - environmental concerns do not enter into the calculation.  The energy prices used in the calculation do not favour ASHP since the electricity price > 3x natural gas price.  Your EPC was calculated with RdSAP 9.94, the old standard.  SAP 10.2 was approved last year but RdSAP 10.2 is not ready as far as I know.  But even 10.2 has energy prices with electricity price > 3x natural gas price (it's actually got worse lol).  The authorities realise that SAP is inconsistent with their green aspirations and does not embody green metrics (read review here).  SAP 11 is being worked on and may address that but that's expected late 2024.

I think EPC is correct there - that ASHPs do not significantly reduce energy costs of the house with the current fuel costs.  The reason comes down to the failure to account for externalities of fossil fuel use.  I expect they will fudge the SAP calculation eventually to come to the "green" answer but the occupants pay energy bills with cash rather than warm green feelings.  Whereas in my view, the honest approach is to build into fossil fuel costs, the full measure of their externalities but that won't go down well with Joe Public.  Energy - cheap, green, dispatchable, choose any two.

@ronin92 thanks 😊 very much fir thr insights!

@andris EPCs can be a load of rubbish, my EPC when I was heating by oil rated my main heating and hot water was 'average' with a boiler that was 80% efficient at best and a thermal store that, by modern insulation standards, was poor:

But after I converted to ASHP with main heating around 300-350% efficient and hot water 200-250% efficient, with a very efficient well insulated unvented hot water cylinder, both are now rated as 'poor':

How can a system that uses massively less energy per annum, much of it renewable and some micro-generated by solar PV, not be rated better than a fossil fuel fired boiler spewing out tonnes of CO2 per year. EPCs and the SAP method behind them are a load of complete bollox if you ask me!

@allyfish, it’s just another broken part of the system. They (whoever they are) were supposed to amend the ‘values’ for heat pumps which were scored much lower than boilers to address this kind of EPC score anomaly (if you can call it that). I guess it still hasn’t been done then, which is crazy because as you’ve said the heat pumps are much more efficient and EPC scores aren’t reflecting this.

@allyfish could not agree more!

@allyfish, I agree

Attached EPC extract compares my own house with a neighbour's. It's laughable that the gov't wants to encourage the use of heat pumps but that the energy rating system puts them at a disadvantage compared with gas or oil boilers. What's worse is that the EPC then contradicts itself and states that heat pumps may help reduce energy bills. Either they do or they don't - which one is it?

This is also relevant to the residential letting market. Currently the minimum EPC rating allowed for a rental property is D. This is soon to be raised to C, which will make a huge number of properties unlettable. My property has a D rating and would no doubt have achieved C, if it were not for the heat pump. This is nuts. You can't recommend people not to install heat pumps if they want to improve energy efficiency. But it's not a route to improving the EPC rating.

Mike

@mike-patrick Just so nuts. 

Here is another one for you. Technically we qualify for free solar becuse we receive certain benefits. They came out had a look and said we'll becuse your house is very well insulated and very afficent u qualify for a 2kw pv. I said what ? Why don't you look at my consumption I use 10000kw a year i have no gas. A 2kw system will do nothing to help. He said sorry we are not supposed to look at the consumption but the house or whatever made no sense. That's when I decided  go for at least the 5k interest free loan for 10 years and I got myself a 8.4kw pv array.

Posted by: @mike-patrick

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@allyfish, I agree

Attached EPC extract compares my own house with a neighbour's. It's laughable that the gov't wants to encourage the use of heat pumps but that the energy rating system puts them at a disadvantage compared with gas or oil boilers. What's worse is that the EPC then contradicts itself and states that heat pumps may help reduce energy bills. Either they do or they don't - which one is it?

This is also relevant to the residential letting market. Currently the minimum EPC rating allowed for a rental property is D. This is soon to be raised to C, which will make a huge number of properties unlettable. My property has a D rating and would no doubt have achieved C, if it were not for the heat pump. This is nuts. You can't recommend people not to install heat pumps if they want to improve energy efficiency. But it's not a route to improving the EPC rating.

 

Mike

-- Attachment is not available --

That's weird. My property's heating is described in exactly the same way as yours but rated as "good". In fact it's the combination of ASHP and solar PV that helped bring the EPC up from a previous "D" to a current "B" and in spitting distance of an "A".

Just seems to demonstrate the lack of fitness for purpose of the EPC scheme rather than anything else. Pity other financial considerations hang off the back of it....

@majordennisbloodnok My EPC says that if I were to  install solar PV as well I would scrape a C rating.

Mike

@andris To rub salt into the wound my neighbour's house is C rated compared to my D but his is not so well insulated and he doesn't have double glazing.

Mike

@mike-patrick 🙈