EPC Rating Not Right?

TractorFactor

Hi

Had our house surveyed for EPC.

They've listed it as an end of terrace but it's a semi detached.

They've also listed:

Cavity wall, as built, no insulation (assumed) as "poor" but the previous EPC certificate showed this as "Cavity wall, as built, insulated (assumed)" with Good as the rating.

The "Roof Pitched, 75mm loft insulation" was Good but now it's dropped to Average.

A previous EPC man came to the house a year ago and drilled a hole in the wall to test as he was offering free cavity wall fill.  He said where he had drilled was wool insulation, which was standard for around the time the house was built.

He told my partner that he couldn't put that the whole house was insulated as the EPC people (?) would require paperwork to show this was fact.  Is that right?  Surely a previous rating can still be kept?

"Roof Pitched, 75mm loft insulation" was Good but now it's dropped to Average.
"Roof Pitched, insulated (assumed)" was Good but now it's dropped to Pitched, no insulation (assumed) with a rating of Very Poor.

The second one will likely be the extension that was built before we bought.
It would have been built from 2005 - 2015 sort of time.

Window - Fully Double Glazed was Good but that's now dropped to Average

No changes to the windows.  In fact we replaced a blown window pane.  They're not in bad shape (granted not brand new but I wouldn't say bad).

I guess standards have moved on (particularly with loft insulation) so perhaps some of the ratings may have dropped a bit but is there something I can do to challenge this?

user1977

Why have you had a second EPC done after only a year?

FreeBear

Thermal performance of doors & windows have changed over time - 2022 saw a requirement of 1.4W/m²K for replacement doors & windows (1.2W/m²K for new builds). So any doors or windows fitted more than two years ago could well drop from a good to average.

Same goes for loft insulation, but with just 75mm, I'd have expected a poor or even very poor rating. Current requirement is for a minimum of 270mm. Would also have expected the extension loft to be insulated when built as it was a Building Regulation requirement at the time.

If you are reasonably fit, shoving more insulation in to the loft space is not difficult, and the stuff is pretty cheap. A low hanging fruit that you can do yourself and bump up your EPC rating by a couple of points.

TractorFactor

user1977 said:

Why have you had a second EPC done after only a year?

I haven't.
The man who came a year or so ago was offering free insulation to another house in the area so said he could check what we had.

theartfullodger

I would expect most EPCs to be incorrect.  And if you get someone else to do another EPC you'll get another answer.  

GDB2222

The prices for EPCs are so low that I can't see how the inspectors make a living at all, really. There's no money in the job to really inspect the property carefully, so it's all based on assumptions.

EssexHebridean

There is a route to challenge - if I remember rightly you go back to the people who did it first, then if they didn’t respond there is an escalation process via the accreditation scheme. It should be noted on your EPC document. 

bobster2

theartfullodger said:

I would expect most EPCs to be incorrect.  And if you get someone else to do another EPC you'll get another answer.  

Absolutely.

I've seen an estate of what were identically houses - all get different ratings. Not just because of differences in upgradeable things (e.g. boilers, loft insulation) but because key parts of house were described differently - e.g. the same walls being described as either cavity wall, timber frame, or system built and them described as having no insulation, partial insulation or limited insulation.

Bilivino

Hi TractorFactor,

The description of the property being incorrect: 'end of terrace' instead of 'semi-detatched' is a very basic mistake on the part of the assessor. Both of those property types will have the same number of party walls and external walls so it might not make much of a difference to the rating (I've not modelled it to know for sure), and that distinction might just be there for reporting/data collection purposes, but you'd expect such a basic thing to be recorded correctly, and if there were other mistakes it would not look good at all re the assessor.

With the part about your cavity wall, I think I can help with what's going on there. Let's take the two descriptions:

1) "Cavity wall, as built, no insulation (assumed)" - from the more recent EPC
2) "Cavity wall, as built, insulated (assumed)" - from the previous EPC

In short, and asuming these descriptions related to the same building part, I think what is causing this difference in description is down to the construction dateband that the assessor has assigned to that building part in the first EPC compared to that assigned in the second EPC. I'll explain this as we go along...

In the first one, the assessor has deemed that the wall is a cavity wall. This may be by viewing the external elevation(s) of the property, noticing stetcher brick bond and noting the thickness of the wall and possibly supporting their view by looking at any bare gable end wall in the loft.

Then, they have looked at those elevations to see whether there is any evidence of retrofitted Cavity Wall Insulation. This would typically be in the form of a series of 20mm diameter drill holes in some of the mortar lines which have then been capped with mortar.

In this case it would appear that they have not found any of those, and had also not been provided with (or accepted) any documentary evidence to indicate the cavity walls have had insulation installed.

Following the rules they have then recorded the Insulation Status of the wall as 'As Built'. This means it is as it was when it was originally constructed. This is indicated by the presence of the words 'As built' in the descrition.

The next part, where it says 'no insulation (assumed)', that is derived by the EPC software (/methodology) automatically due to the 'As Built' insulation status of the wall. The system refers to the dateband that the assessor has assigned to this part of the property. If you are really interested to research further, there is a table of Wall U-Values, I think it's in the SAP 2012 appendix S document on the BRE (Building Research Establishment) website (I might not have that quite right though), and that shows how those U values changed over the years. These are effectively the worst case U-Values for walls as required by building regulations at the time over the years (albeit delayed by one year). There is a year at which the EPC software assumes that a cavity wall has insulation fittted in order to meet the ever tighter U-value requirement of the building regs and that seems to work out at 1983. So for the 1st description where it says 'no insulation (assumed)' which is from your recent EPC, I would suggest that the assessor appears to have assigned a dateband to this building part prior to 1983.

With the second description of your cavity wall, from the earlier EPC, I would suggest that exactly the same procedure and findings have been followed by the assessor at that time, but they have assigned a dateband to that building part which is from 1983 onwards instead.

I've come across this before, more than once.

I wonder, and there's no need for you to tell us the year, but I wonder whether you know a fairly accurate date of construction of your property?

Because you mention previous intrusive inspection finding cavity wall insulation, and I'm asuming both assessors were correct in not finding evidence of cavity fill holes in your wall, if I was a betting man I'd guess it might be 1983 onwards.

If it is indeed after 1983 then I would suggest the recent EPC has had the wrong dateband assigned. If this is the case then even on its own, and more so when combined with the mistake with the property type (semi/end terrace) there's clearly enough informaton to approach the energy assessor to ask for that to be corrected (might be worth helping them by supplying any information you have about the date of construction, so they can add that as evidence to support this choice). There is information about how to do this on the EPC itself. The first approach should be to contact the assessor direct and then if you are still not happy you can approach the accreditation scheme that they are sigened up to, which is also detailed on the latter part of the EPC (Elmhurst/ECMK/Quidos etc.).

Alternatively, if the year of construction of your properrty is actually prior to 1983, then it may well be that the newer EPC is 'correct' in the status of the wall (in the absence of visual or documentary evidence of CWI), and the previous EPC had the 'mistake' with the dateband.

A question for you: and apologies I've run out of time tonight so haven't re-read your orginal post, but is that the only Wall entry in the Features tables from the EPCs, or is there another? (one for the main building, and one for the extension you also mention in your post). I've been assuming this cavity wall description is from the main part of your building, but you do mention an extension built between 2006 and 2015 in your original post, and if that was also a cavity wall then you'd certainly expect that to be 'insulated (assumed)' due to the recent construction date. If they were of different insulation statuses, you'd expect entries for both walls to be present in the Features table.

When I get more time, I'll look at your original post again and see if I can say something about your other observations.

Hope that helps,

All the best,

Bilivino

Bilivino

From further research I've learned there are three datebands regarding the assumption of insulation in 'As Built' cavity walls:

Prior to 1976 - assumption for 'As Built' is no insulation

1976-1982 - assumption for 'As Built' is partial insulation

1938 onards - assumptin for 'As Built' is insulated

FreeBear

Bilivino said:

From further research I've learned there are three datebands regarding the assumption of insulation in 'As Built' cavity walls:

Prior to 1976 - assumption for 'As Built' is no insulation

1976-1982 - assumption for 'As Built' is partial insulation

1938 onards - assumptin for 'As Built' is insulated

1938 cavity walls will most certainly NOT have any insulation as built.

1976-1982 might have insulation, but it is not guaranteed - My 1976 extension didn't have anything in the cavity, nor in the flat roof.