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

Reply to the comment left by WP at 28/10/2020 - 17:39
From that result, It looks as though the assessor had the age band of the extension wrong on the EPC.

Question for an EPC assessor (for commercial - shops).

I need a couple of EPCs doing for shops with flats above. My question is, is there simply a box to be ticked for "flat above", or is the quality of the insulation in the shop's ceiling/flat's floor taken into account?

They're Victorian terraces and will likely be marginal score-wise, and I'm wondering whether I'll have to chop into the ceiling or rip up laminate floor, sound-attenuating floorboards to show the assessor the insulation bales, which are now of course totally inaccessible.

Many Thanks

I can only speak for from the point of view of the dwellings. The EPC only needs limited information when there is an inhabited area below - either "Another dwelling below" (eg another flat) or "Above a partially heated space" (eg shops or offices). There is no provision for entering the insulation thickness etc into the EPC in these particular cases. I only do domestic EPC's so I don't know how the EPC's for the shops would be entered. Hope that helps.

Reply to the comment left by Gunga Din at 03/12/2020 - 13:47
Hi Gunga,

When we conduct a commercial EPC we look at the structure as a whole. So if part of the ceiling is, for example, a flat roof, that is calculated into the parameters. Saying that, the SBEM software we use, have preset cursors that are selected based on classification and age of the property. If this info cannot be obtained the worst case scenario is assumed.

If there is a flat above, we can choose to input the parameters of a separating floor, whether concrete or timber and if it is suspended tiles found is some office buildings.

There is a parameter that we can enter the u-values for that section, but these need to be provided/calculated prior to the inspection with the evidence to back the figures such as photos of the insulation and the receipts etc.

If there is a building regulations certificate to state it was done to current building regs, this can be entered for the ceiling showing it complies, but again evidence is required.

Hope this helps?

Thanks for those replies gachilleos and Simon Holloway. I'll gather the evidence and speak to the assessor.

Gunga Din

For me the EPC rating turned out to be a handicap in the sale of my property.
I installed 32 mm double glazing, consisting of an 8 mm toughened and an 8mm laminated sheet. The outside walls are 28 cm thick cavity walls, with the result that my flat stays at around 22 degrees all year round and exceptionally needs heating when the temperature goes around 19 degrees inside, outside under 6 degrees for an extended period.
I kept my old indirect geyser system because that provides warm water even if water, gas or electric supplies fail and that system can be fed by a heat pump if necessary, while a heat pump can not provide warm water for a shower directly.
Because the ECP rating calculation does only notice double glazing without making allowance for quality and because it gives me a lower rating for using an old boiler... which I hardly use, I now get a lower rating for very efficient condition.
Can I not get a real energy efficiency valuation somewhere?

Hi Jeff, recommend you talk with your assessor. It is allowed to overwrite the default U value for the glazing if you have the manufacturer's U data sheet. If the geyser is a secondary heating source for the water, then this should not even be considered. Trust the assessor gave credit for the cavity wall insulation, but please check as may have omitted if not evident.

I believe it is time for the industry to question the software and test its outputs against the real world. Here is another example of a property's rating being changed from C to D (making it un-rentable from 2025) even though nothing had changed to justify the rating change.
The property, a 83sqm, 3 bedroom 1950s semi-detached property with modern condesning gas combi boiler, all LED bulbs, filled cavity wall insulation and loft insulation was downgraded by the "new" software from its 2011 C rating to a D rating in 2022.
All can discuss the "assumptions" made by the software, but what they can't do is deny the real world energy use by the property.
This property was fully occupied during a 3 year period of March 2019 to March 2022 (here referred to as "the COVID years", so it would have been using more energy than a normal household). During that time it used 1051 cuft of gas, using an average calorific value this is 33,807 kWh of gas over 3 years. this makes it an average of 11267kWh/yr. If we add 220kwh for LED lighting (which is 20 bulbs on for 6 hours a day every day) and we add a significant 1000kwh for other electricity use related to heating and maintenance of a home (not including fridge, freezer, cooking, kettle, tv, internet and other non heating related phantom loads), we get a total use of 12,487kWh per year usage. This makes its Primary Energy use per year 150kWh/sqm. The EPC output shows "Primary Energy Use" as a stated number per year of kWh/sqm, so the calculation above can be compared with an EPC output.
The average real world Primary energy use for this property per year over a 3 year period was 150kwh/sqm.
2011 EPC for this property calculated it as 173kwh/sqm
2022 EPC calculated it as 235kwh/sqm
So the software was close in 2011, but the new software has added 57% extra energy use when compared with the "old" software. Is this due to erroneous inputs? or software assumptions?
Everyone should not just accept an EPC but should check its output with the real energy use of the property, and the industry should not just be saying "The Computer Says So", but be "stress testing" the outputs by comparing them with real world energy use (where possible). This way the "system" can be made more accurate and reduce the number of erroneous EPC category changes.

"If we add 220kwh for LED lighting (which is 20 bulbs on for 6 hours a day every day) and we add a significant 1000kwh for other electricity use related to heating and maintenance of a home (not including fridge, freezer, cooking, kettle, tv, internet and other non heating related phantom loads), we get a total use of 12,487kWh per year usage. This makes its Primary Energy use per year 150kWh/sqm. The EPC output shows "Primary Energy Use" as a stated number per year of kWh/sqm, so the calculation above can be compared with an EPC output".
I only noticed this today, Electric consumption seem way too high for a 3 bedroom property,
So if you take yearly consumption quoted above as 12487kWh, that averages 34.2kWh per day, far too high according to my opinion especially if the primary source of heating is condensing combi boiler.
I have a large 3 Bedroom property and my electric consumption used to be around 4500kWh last year and this year I have taken radical measure to bring it down to around 2200 kWh, and I am on target.
So the point is can we base EPC ratings on occupiers habits, how they use electricity or heating, some occupiers may be happy with 20c heat during winter some may want it at 25c, all of this can make a hell of a lot of difference, the higher is the heat setting higher is the heat loss,
Another thing I have been looking at is Internal Insulation v/s external, again according to my own opinion and experience, external insulation is not as effective as Internal insulation, since with an external insulation you would need a lot of heat energy to bake your walls, if walls remain cool then they will make the room go cold very quickly as they absorb heat, so if you only occupy your home for 12 hours a day and rest of the time you are out to work and commuting, you would tend to put heating on when you have come back home and switch off when you go out, this does not make the walls get to a steady temperature whereby they no longer feel cold and so do not require to steal the heat from the room you are trying to heat, in other words external wall insulation works best when the heating is on constantly and the walls have acquired a comfortable temperature such that when the room feels cold it only needs a bit of heating to top up,
So the whole thing about EPC is rubbish, it depends on a software written by men not aliens from outer space, and depends on inputs entered by incompetent and arrogant humans, so I rubbish all EPC reports if I were given a low rating I would fire that assessor as useless waste of space if he wants evidence for everything we do in our homes, often we do not bother to keep receipts or take photos, so if an assessor insists upon evidence fire him , don't pay him. You have got to be arrogant to deal with arrogant incompetent and unhelpful people, we have loads of them around. Look for a one who understands things.

You make a very good point, Mike, regarding the benefits of internal v external insulation.

Obviously, the comparison is "everything being equal" and, in reality, it is likely that internal space limilations will necessitate thinner insulation, in which case external MIGHT be the better option.