Heat Pump EPC bad

northwest1965

I'm viewing a property this week with a heat pump. Why would the EPC be so bad??

What information do I need to obtain from the vendor?

It's an old cottage

Reed_Richards

When is the EPC dated?  Until a year or two ago EPCs rated heat pumps as electric heating and all electric heating was rated as poor because many forms of electric heating are very expensive to run compared to heating with gas or oil.  This blanket generalisation does not apply to heat pumps, nor to night storage heaters run with an Economy 7 tariff (or similar) for that matter.  But EPCs are created by someone who probably understands little about the fundamentals feeding data into a computer program which then pops out the EPC.  The program did not  take the efficiency of heat pumps into account so rated them as poor, an example of something I call "Artificial Stupidity".

I thought the EPC program had been changed to recognise the efficiency of a heat pump and give it the same rating as a gas boiler.  If that didn't happen it's scandalous but I think it more likely that you are looking at an EPC that is a few years old but not so old that it isn't regarded as current.  This could indicate that the property you are looking at has been on the market for several years without selling.

     

Exiled_Tyke

A quick 'google' brought up this: 



Looks like it's purely a cost issue and with less than great insulation the ASHP could be more expensive than gas.   If insulation can be beefed up and a decent TOU tariff found I'm sure you could get this working in a cost effective way 

Reed_Richards

I think the 'Google' AI comment is another example of AS, "Artificial Stupidity" because it doesn't know the rules have changed.  At least I sincerely hope the rules have changed, we were certainly told it was going to happen. 

paul991

Because Epc, s are not fit for the purpose and heat pumps are designed to be  run 24 /7 with all zones fully open. I would get the make model design spec and put it on here and let the forum comment on it.

Reed_Richards

A lot of misinformation surrounds heat pumps.  Heat pumps are NOT designed to be run 24/7 nor with all zones fully open.  That could be the way to run a heat pump most efficiently under certain circumstances, for example if you have Underfloor Heating throughout.  But the heat pump isn't going to be harmed if you choose to run it differently* and there are lots of other choices that will achieve similar levels of efficiency.  If you heat with radiators then you may well want to set-back the required temperature in your house overnight to something a bit cooler; many of us find that more comfortable.  It's still a topic of debate whether that is more or less efficient than running at the same temperature 24/7 which means that any difference is slight.

* Many heating systems don't like to be turned on and off very frequently, by which I mean every few minutes.  If your control system is causing that to happen (it's called "Short Cycling") I think it's likely to be more harmful to a gas or oil boiler than it is to a heat pump but in all cases you should try to ensure it doesn't happen.        

matelodave

As far as I understand it the EPC is based on the amount of heat energy the house requires to heat it together with the cost, but doesn't take into account where that heat comes from so doesn't take into account the efficiency or carbon emissions of the heat source.

Because electricity is 3-4 times more expensive than gas, a heat pump costs about the same to produce the same amount of heat as gas or oil even though it actually uses a third to a quarter the amount of electrical energy to do it.

In many cases changing from gas to a heat pump can actually make your EPC worse.

We have a reasonably well insulated bungalow but can still only manage a D rating on our EPC because we have a heatpump (however that's much better than the F it had with storage heating)

It's the perverse way that EPC's were devised without actually understanding the benefits of a heatpump

The_Green_Hornet

Reed_Richards said:

I think the 'Google' AI comment is another example of AS, "Artificial Stupidity" because it doesn't know the rules have changed.  At least I sincerely hope the rules have changed, we were certainly told it was going to happen. 

The new rules don't come into effect until 15th June with the introduction of RdSap 10.

EPC Changes June 2025: What You Need to Know

northwest1965

Reed_Richards said:

I think the 'Google' AI comment is another example of AS, "Artificial Stupidity" because it doesn't know the rules have changed.  At least I sincerely hope the rules have changed, we were certainly told it was going to happen. 

The EPC is dated February 2025.
Current owner bought property in October 2024, did the insulation/heat pump and now property is empty

matelodave

northwest1965 said:

Reed_Richards said:

I think the 'Google' AI comment is another example of AS, "Artificial Stupidity" because it doesn't know the rules have changed.  At least I sincerely hope the rules have changed, we were certainly told it was going to happen. 

The EPC is dated February 2025.
Current owner bought property in October 2024, did the insulation/heat pump and now property is empty

Therefore the EPC was produced under the existing rules which seem to go back around 20 years (my EPC was produced in 2012 so I could apply for the RHI (Renewable Heat Incentive payments)) .

The new rules don't come in effect for another week (15th June) so I guess that an EPC produced after that date will have a significantly different rating.

 IMO the EPC was only a wet finger in the air guess - I had several done over a couple of years when we sold my MIL's house, my Mums house, our house and got one after the heatpump was installed.

None of the assessors really knew what they were doing, they were just box ticking and putting a few measurements into a software program which spewed out an EPC. I guess that even the new one wont be much better as it still relies on someone filling in even more boxes into a program which produces the EPC.

Its supposed to be more representative and take into account the type of heating and its efficiency but as you can get an Assessors certificate as a correspondence course on line and buy the software on line, I dont' really think that its going to be a lot better. apparently the new rules require the use of a proper ruler to measure the size of each window rather than guessing 

Reed_Richards

The_Green_Hornet said:

Reed_Richards said:

I think the 'Google' AI comment is another example of AS, "Artificial Stupidity" because it doesn't know the rules have changed.  At least I sincerely hope the rules have changed, we were certainly told it was going to happen. 

The new rules don't come into effect until 15th June with the introduction of RdSap 10.

EPC Changes June 2025: What You Need to Know

There you go!  These changes for the EPC assessment of heat pumps were announced two years ago, if I remember correctly.  And here we are in 2025 and still they haven't quite come into operation.  Given that the way heat pumps were assessed was totally wrong, I really do think this is a scandal.  But maybe I can now get a better EPC than @Screwdriva (on the Green & Ethical board) with his super-efficient gas boiler.