EPC clearly wrong so can Assessor be made to change it once issued?

The simple answer is yes, you can challenge it. You have a commercial arrangement (contract) with the provider and they have a duty to get it right. The surveyor should be able to explain his rating and if there are errors he should amend them.

If the surveyor won't speak to you directly then you are well within rights to go to his firm and find get the answers you need.

Go to the company directly.

However, if recent assessor has reason to believe that previous assessor made errors, then he will be obliged to corrrect them.

That said, if you can show that new assessor has made errors, then the company should be able to forward the evidence to their assessor for him to correct.

Note that the method of assessment has been refined over time, such that a property rated today can have a lower energy rating than 10 years ago, even if no changes have been made.

Some people wrongly believe that this reduction in rating is due to an "aging degredation" being built into the system (eg. boilers get less efficient over time and windows get draftier).

On the other hand, the potential figure does increase over time due to technological developments (eg solar panels and heat pumps).

Sounds like a cow boy Assessor! Obviously incompetent and should challenged and ask for a complete refund and engage another competent assessor.

You should also have been there with him and asked him questions, regarding his ratings, it seems the ratings can vary widely between different Assessors.

Reply to the comment left by Mike at 16/10/2020 - 10:52
Mike, you obviously haven't got a clue how a DEA does a property assessment or how the assessment protocols have changed over the years. eg if there is no physical proof from the owner/visual about age or build of the property it must always be assessed as worse case scenario. Not enough information from original poster about EPC points to gain a full understanding of the situation.
The ONLY correct answer is to contact the assessor, number etc on the EPC and ask relevant questions. If he fails to respond, contact the accreditation firm he lodges with, again details on the EPC. 2sqm of floor area will not make any difference to the rating, unless your building is perfectly square in all rooms you will never get the same result.

A DEA has to make their assessment based on evidence of building build age and construction details, which for some types of buildings can be tricky, so not unusual for there to be some difference in SAP rating, particularly when reworking an assessment from circa 10 years ago. Hence importance of ensuring the assessor is provided with key construction details where the building is unique or twerky.

The Assessor has no more access to the assumptions used in the original assessment, other than the brief descriptions on the certificate. So it may be the original assessment made incorrect assumptions.

Since the EPC first introduced there have been changes in Conventions and calculation methods, so not unusual for renewed EPC to be lower than original issue.

That said, if the Assessor has not responded to clarify their assumptions and have the discussion then raise the issue with their company.

Reply to the comment left by Mike at 16/10/2020 - 10:52
You actually have no idea about the competence of the EPC surveyor. It may be that the first one was wrong! Things may have changed with the regulations and, perhaps with the property itself. The size issue if irrelevant.

As I said before, the OP can only get more information by asking the surveyor, or his company if he doesn't respond himself.

Reply to the comment left by at 16/10/2020 - 13:16yes I have lots of ideas, every industry from Judges to courts to prime ministers to you name it have cowboys in them , that includes rogue landlords, rogue tenants, the whole human race is not on competent level one. If an assessor cannot assess the age of a house without evidence, he should not be in the job.

Remember, even the police officers can be criminals, bad cops, so can be the Assessors bad assessors, incapable of assessing correctly.

Thanks all. Have contacted the company and they have stated it is the original assessor that need to be contacted and only they can amend a report if necessary. I have fired off an email to assessor with my concerns and asked for a prompt reply. The total irony is that as he has rated it an F , I can't get a grant for help with further measures to increase its energy efficiency! Doh!

Reply to the comment left by WP at 16/10/2020 - 13:53
Response fom company does not make sense. In the unlikely event that you could contact original assessor, what would you be asking?

BTW, how much were you charged for the new report?

Reply to the comment left by Ian Cognito at 16/10/2020 - 14:02
Here is my email....
Hello X
Thanks for conducting the report at the above address. I have though a few questions about this report, its findings and overall rating.
Bit of a shock to get a 'F' bearing in mind the last report so I have looked through to see why this is the case and have noted the following:-
1. The total floor area is marked up at 60 sqm, previous report 58 sqm. There have been no additions/extensions to this property since the previous EPC was produced.
2. The property type is listed as ground floor flat, previous report states Top floor flat. This has implications in regard to your recommendations. If you look at the attached photo of the plan at the top left, you can see the majority of the floorspace of the flat is actually above the underneath neighbouring flat. As part of the need to provide noise and fire protection measures between these flats, this would have included floor insulation when built.
The much less floorspace to the left of the front door is on the ground floor. This was an extension built in 1995 again where Building Regs required insulation standards to be met. It is therefore incorrect to suggest that no insulation is assumed in this property
3. The previous report stated 100 mm of loft insulation - Average. Your rating of the same very poor.
4, Previous report, Cavity wall, as built insulated - Good. Your report assumed no insulation - Poor. (NB The part of the building that has cavity walls was built in 1995 and was built according to Building Regs at the time which would have included insulation. I also attach a copy of the Planning drawing showing this - see bottom right of the plan)
5 Previous report Timber frame as built insulated - Good, your report assumed only partial insulation Average. It is either one or the other!
While I understand in separation the above concerns may be deemed minimal, but collectively they may well have ensured an incorrect rating for this property.
It is actually a bit ironic that the reason that a new EPC is being sought is precisely to enable me to determine what measures I can take to bring the efficiency rating up. Having been rated and F (and not E or above) now actually discounts me from applying for grants to make specific changes to this property to improve the environmental impact.
I know we are singing from the same environmental hymn sheet here - I used to be a Quality and Environmental Manager in a large engineering company so am, like you very keen to move towards the best energy efficient outcomes where possible.
In light of the above I'd be interested in your comments, though moreover amendments to the report to ensure proper consistency with reference to it. Clarity is key to ensure such certifications and their recommendations are to be held in such regard that effective action can actually be taken to assist in long term environmental improvements.