Green Building Forum - EPC system changes Wed, 23 Sep 2026 17:58:11 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302798#Comment_302798 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302798#Comment_302798 Wed, 09 Aug 2023 15:33:46 +0100 WillInAberdeen
Instead of the current A-G bands based on £/m² costs of heating, the new EPCs will show:

- heat loss on A-G scale (irrespective of how that heat is supplied or collected)
- cost on A-G scale
- heating system classification IE "zero emissions" or "not zero emissions"

Buried deeper in the EPC will be:

- CO2 emissions A-G scale
- external energy purchased in kWh per m² (including for lighting, hot water etc)



The gas boiler people are angry because gas heated houses currently have good EPCs because gas is cheap, their EPCs will suddenly get several bands worse when they become based on heat loss.

The heat pump and PV and passivhaus people are angry because the "heat loss" metric doesn't reward renewable heat or passive gains, compared to fossil heat.

The EPC validity will be for five years instead of ten. More details about the house will be published online than currently, to enable searches.

Still using rdSAP data from 2012. Maybe moving up to SAP11 when that comes out.

Rental properties still require EPC band D by 2025 and band C by 2028.


https://www.gov.scot/publications/energy-performance-certificate-epc-reform-consultation/documents/]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302799#Comment_302799 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302799#Comment_302799 Wed, 09 Aug 2023 16:45:47 +0100 djh Posted By: WillInAberdeenThe heat pump and PV and passivhaus people are angry because the "heat loss" metric doesn't reward renewable heat or passive gains, compared to fossil heat.Do you have some links for those statements please? After a quick read of some of the consultation document those concerns appear to be misplaced, so I'd like to understand them more and perhaps comment to those who are angry unless I am convinced I have misunderstood the consultation.

Specifically as to 'the heat pump' people's stated concerns, the 'heat loss' metric doesn't say anything about the type of heating and so can't reward a particular type of heating or penalise one either. That reward will come out in the cost and/or the 'net-zero' compliant metrics, I think.

As to the PH people, I don't understand their concern at all, since the 'heat loss' is stated in terms of the heat supplied - "The energy required to be supplied by the heating system to achieve standardised internal conditions" - and this is affected by passive gains. (as long as it is calculated by some method such as PHPP which accounts for them, or is measured directly in the real house). Indeed it is very close to the primary metric used by PHPP, so I don't understand why they would be upset.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302800#Comment_302800 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302800#Comment_302800 Wed, 09 Aug 2023 20:07:32 +0100 WillInAberdeen
They have decided EPCs will still be calculated with rdSAP, so rarely using full SAP, and they decided not to allow PHPP.

rdSAP treats a PH as having the same U values and airtightness as typical buildings built the same date. It doesn't evaluate detailed solar gains etc like PHPP does so assumes that heat is drawn from the CH (or fan heaters, if the CH isn't that big). So the PH will get a not-very-brilliant EPC, seems a missed opportunity.

rdSAP is still part of SAP 2012 so uses carbon and cost figures from way back then. Those strongly favoured gas, and not electricity.

As proposed, fitting an ASHP or solar onto an existing gas-heated house will make exactly no difference at all to the EPC band. So hard to see how that will encourage take up, despite the intention of tightening EPC requirements in order to drive down residential energy demand. In contrast to the legislation for new builds, in which ASHP and solar are both credited.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302801#Comment_302801 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302801#Comment_302801 Wed, 09 Aug 2023 20:18:07 +0100 djh
And no, I am not thinking about Building Standards regs.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302867#Comment_302867 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302867#Comment_302867 Thu, 17 Aug 2023 20:50:53 +0100 djh
For anybody else interested in the subject here's another view from an organization called Common Weal that I'd never heard of: https://commonweal.scot/policies/energy-performance-certificates-an-alternative-approach/

And yes, personally I'm strongly critical of rdSAP, although I think I do understand its attractions to policymakers. EPCs are required for new builds as well, though fortunately SAP is used instead of rdSAP, for what little comfort that is.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302872#Comment_302872 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302872#Comment_302872 Thu, 17 Aug 2023 22:56:17 +0100 WillInAberdeen
Would also be good to keep on the substantive topic for at least the first few posts.

Here's a flavour of public discussion which is not always on point:

https://www.heraldscotland.com/news/23670366.gas-boilers-set-penalised-energy-efficiency-overhaul/

https://www.edinburghnews.scotsman.com/news/opinion/columnists/patrick-harvies-heat-pump-plans-are-nothing-more-than-hot-air-susan-dalgety-4235754


A more considered view is from the CCC who recommended that EPCs be based firstly on 'energy use' and then on 'fabric space heating', 'heating system type' and 'cost'. The first would recognise improvements such as heat pumps and PV that reduce energy use from public supplies, the second would reflect 'inspectable' insulation such as in lofts (although insulation buried in walls and floors is not inspectable for rdSAP).
https://www.theccc.org.uk/publication/letter-reform-of-domestic-epc-rating-metrics-to-patrick-harvie-msp/

For reasons unclear, the recent Scot gov proposal includes only the last three measures, so will not recognise heat pumps or PV as ways to meet the EPC C energy target. This is a change from recent policy, such as newbuild standards and retrofit grant schemes.

On this basis, BRE found that 65% of the housing stock are physically capable of meeting EPC C if they have inspectable wall, underfloor and roof insulation added, the rest will not (so will not be let-able and later not saleable).They didn't say how the insulation under slab floors is going to be inspected!

Virtually no homes will get to EPC B under rdSAP 2012, only newbuilds on their first 5-year EPC (for which full SAP can be used). So PHs will drop to EPC C after that time.
https://www.gov.scot/publications/bre-client-report-development-work-relating-potential-new-metric-scottish-energy-performance-certificates/

Worth also understanding the political context in Scotland where the SNP do not quite have a parliamentary majority and govern together with the Greens. The Greens have used this influence to launch very ambitious/idealistic reforms (DRS and others) which the SNP subsequently backed away from when the impracticalities became clear, blaming their junior partners and/or England. Maybe the same here.

ETA: the 'commonweal' proposal is to use last year's energy bills to award the EPC - the practical problems with this have been well discussed.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302873#Comment_302873 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302873#Comment_302873 Thu, 17 Aug 2023 23:08:30 +0100 WillInAberdeen EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302884#Comment_302884 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302884#Comment_302884 Sat, 19 Aug 2023 12:33:31 +0100 djh
I'm not sure what you think the 'substantive topic' is or what your opinion or goal is.

Having a proper fabric efficiency measure as a primary measure sounds sensible to me. Then having separate measures for heating system type and for renewable energy generation etc also sounds sensible.

There are lots of details that I could comment on but shan't at this stage. The biggest practical problem may be the need for twice as many EPC assessors if they shift to 5 year validity, as well as retraining them all to the new system.

Posted By: WillInAberdeenVirtually no homes will get to EPC B under rdSAP 2012, only newbuilds on their first 5-year EPC (for which full SAP can be used). So PHs will drop to EPC C after that time.
My PH got EPC C when assessed under SAP when it was built. (SAP *must* be used for a newbuild) So there's no question of it 'dropping' to C :cry: Typically higher rated houses seem to have a lot of renewables. I'm not sure there's much value in that.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302894#Comment_302894 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302894#Comment_302894 Mon, 21 Aug 2023 07:02:34 +0100 borpin Posted By: djhMy PH got EPC C when assessed under SAP when it was built.Wow. My non PH certified house was B (86) and 60 kWh/m². I always find this figure misleading as I use more IT related power than most. However, with just 2 of us in the house, my rolling use is currently 57 kWh/m².

Posted By: WillInAberdeenVirtually no homes will get to EPC B under rdSAP 2012, only newbuilds on their first 5-year EPC (for which full SAP can be used). So PHs will drop to EPC C after that time.
Does this mean if reassessed, my EPC rating is likely to drop even though nothing has changed!

Posted By: WillInAberdeenBRE found that 65% of the housing stock are physically capable of meeting EPC C
35% of housing stock not saleable - wow! Only option is to demolish them. That asset you thought you had and paid a mortgage on for 30 years is now pretty much worthless. Hand back the keys now.

What a barking system.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302900#Comment_302900 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302900#Comment_302900 Mon, 21 Aug 2023 11:00:57 +0100 WillInAberdeen
"EPC rating is likely to drop even though nothing has changed!" "What a barking system" - yes indeed. This proposal is still open for consultations, link in the OP.

Seems to me that an off-grid renewable-powered property with zero emissions and zero energy bills, should get EPC A, and other properties should get proportionately worse. But under this proposal, that property could get a poor EPC, based on its year of build in rdSAP.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302909#Comment_302909 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302909#Comment_302909 Mon, 21 Aug 2023 22:24:14 +0100 chrisinbrighton EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302912#Comment_302912 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302912#Comment_302912 Tue, 22 Aug 2023 00:17:47 +0100 Artiglio
Already happens.

I built a block of 4 small flats in 2004 with the intention of renting , the first EPC came in at B’s all round , 10 years later they were all assessed as being very average C’s, with the varying news on energy efficiency and possible changes to the assessment i decided to lock in the C’s for 10 years in view of them all having had new gas boilers , uprated heating controls and ensured Led lights everywhere. So had the epc’s done again this year , 5 years early.
Now all good C’s not far from B’s but no practical/economic way to make the jump.

Hopefully in ten years there’ll be a coherent and stable set of rules and regs , along with a mature well supported industry revolving around what is eventually deemed the correct path to follow. Though it looks as though the proposals around energy efficiency standards in the rented sector have been kicked well into long and fast growing grass. If gas is to be less advantageous under any new assessment procedure huge swathes of the current private rented sector will be made unviable as a business or totally unaffordable to tenants if the work is to have any sensible payback period. Being unable or unwilling to meet any new standard must surely be grounds for gaining possession of a property to enable it to be sold, the mess the private rented sector is getting into as overall stock is being reduced has likely woken a few in the corridors of power to the consequences of endless meddling.
Fortunately scotland has decided to test the water first.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302913#Comment_302913 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302913#Comment_302913 Tue, 22 Aug 2023 09:43:29 +0100 Dominic Cooney Posted By: borpinWow. My non PH certified house was B (86) and 60 kWh/m².

Wow indeed, our non-PH certified barn conversion was also B (82) with 81kWh/sqm per annum for space heating and 2,000kWh per annum for hot water. (GSHP for both)
Total area 78 square metres
apparently 2.5kW of PV would get me to an A (94)
Total conversion cost £85,000 including the GSHP, we already owned the building.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302916#Comment_302916 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302916#Comment_302916 Tue, 22 Aug 2023 10:31:48 +0100 WillInAberdeen apparently 2.5kW of PV would get me to an A (94)"

That sounds excellent to me, but the proposed Scottish system will not give credit for the GSHP or PV, or for renewable hot water.

The threshold for EPC C will be set at 71kWh/m² of space heating in rdSAP irrespective of the heat source (ref BRE link above), so Dominic's house would be downgraded from present EPC B, to a D or worse under the new system.


>>>>>"Is it likely that there will be exemptions for loads of properties...such as listed buildings,conservation areas"

No exemptions in these proposed regs, about how EPCs are allocated in Scotland.

There will be separate regs this winter for the "it must be EPC C to be rented or sold" bit. Presumably there will have to be exemptions as only 65% of housing can technically be upgraded to EPC C without giving credit for heat pumps or PV, and there will also be non-technical reasons such as LB/CA. The minister has been putting a positive spin, that this means "the majority" of properties can/will comply.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302926#Comment_302926 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302926#Comment_302926 Tue, 22 Aug 2023 16:07:03 +0100 Dominic Cooney ]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302930#Comment_302930 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302930#Comment_302930 Tue, 22 Aug 2023 19:37:04 +0100 revor In 2021 our 1st full year used 3266 kWh of propane gas
and about 4000kWh of logs difficult to quantify as do not know the weight.
Used 3099 kwh of electricity" the total load " but only 811 came from grid rest was solar.
Hot water do not have a clue as most came from solar thermal and some from the heating propane.
In total we used 10365 kWh House is 340 sqM so 30.5 kWh/sqM.
Costing distorted by the subsidies last year but we only "paid" for the propane and grid electricity, logs came of our land as fallen branches and we got a good price for our export of electricity which totalled 3324.6 kWh at variable rate. So with that and fuel payment worked out well we were net surplus £.
Where would be on the EPC scale goodness knows hope and it would be good, though it would be an academic point.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302931#Comment_302931 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302931#Comment_302931 Tue, 22 Aug 2023 20:08:31 +0100 Artiglio
Had a tenant move out today , been there for 3 months shy of 18 years. Meters unchanged in that time.Small 33m2 one bed top floor flat in a small block built to regs in 2004. Gas for heating ,hot water via combi boiler, boiler replaced with condensing type 4 years ago, gas hob electric oven .East Kent Coast.

EPCs. 2008. 82B
2018. 72C
2023. 76C

Total gas use 4331 M3
Total electricity use 25172 kwh

Tenant was benefit dependant and had a frill free lifestyle, did have a washing machine throughout the tenancy.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302935#Comment_302935 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302935#Comment_302935 Tue, 22 Aug 2023 20:40:37 +0100 djh Posted By: ArtiglioTotal gas use 4331 M3
Total electricity use 25172 kwh
I presume that was over the 18 years. The gas converts to 139269 kWh I think. So a total of 9136 kWh/year and 277 kWh/m²/a which seems rather high with a decent EPC but maybe small properties use more proportionately?]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302936#Comment_302936 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302936#Comment_302936 Tue, 22 Aug 2023 21:58:13 +0100 Artiglio EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302937#Comment_302937 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302937#Comment_302937 Tue, 22 Aug 2023 22:53:53 +0100 WillInAberdeen
EPCs reward those properties with efficient shapes (such as flats with few external walls), unlike newbuild SAP calcs for Building Standards/Regs.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302940#Comment_302940 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302940#Comment_302940 Wed, 23 Aug 2023 08:42:08 +0100 Artiglio
My view over the years is that the epc is a reasonable predictor of use but it all becomes meaningless when the actions and behaviours of the occupants comes into play, when you’ll get huge variances in energy use. As i’ve mentioned before a decent public education programme in respect of energy use would probably be the most effective energy efficiency intervention available and certainly the most cost effective.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302945#Comment_302945 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302945#Comment_302945 Wed, 23 Aug 2023 10:13:38 +0100 Peter_in_Hungary Posted By: ArtiglioI’ve another longterm tenant in a mid floor 2 bed flat, i’ve asked if they have any details on energy use i could look at, they said yes but will be amazed if they actually pass anything on,
Don't you keep tabs on the utility bills to see that they are paid. Over here debts run up to utility companies can and are attached to the property so a land lord can suddenly get a nasty surprise.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302948#Comment_302948 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302948#Comment_302948 Wed, 23 Aug 2023 11:55:43 +0100 djh Posted By: ArtiglioI think you’ll find the m3 to kwh conversion factor is around 11.2 so total would be 48,507 , so roughly 83 kwh/ m2/year. Which is a bit less than the epc estimate.Apologies, you're quite right. I used the wrong setting on the converter :shamed:]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302950#Comment_302950 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302950#Comment_302950 Wed, 23 Aug 2023 14:33:11 +0100 Artiglio All gets complicated with prepayment meters especially if the previous tenant has run up a debt and walked away. That can get really difficult mainly because you just can’t talk to a human and all the data protection rules. In my pther block the number of debt collection letters that arrive is incredible and some refer to tenants that left 15 years ago. I’ve a tenant that left 2 years ago and obviosly owes money to hmrc, about 5 letters a week come for that person. I used to put “no longer at this address , return to sender” and stick them back in post, but it’s a pointless exercise that does nothing. Now they just get binned.
You always know when a departing tenant has left a trail of debt, they have terrible trouble remembering their new address, so i just ask them to put “ forwarding address declined” on the check out form and sign next to it. Then if any entity gets the hump i email a copy to them along with the date they left.
The tenant that has just left, took me for £1300, made no effort to clean anything , now has the gold medal for the filthiest toilet i’ve been left with ( a gallon of acid so far and its still a bubbling cauldron of filth), had left by the yime i arrived for the checkout and no forwarding address, so there’ll be a few outstanding bills for them. But being benefit dependant and no assets they can pretty much do as they wish , the evil wicked landlord would be expected to bear the loss by the courts so a waste of time and money chasing them. But it’s the last benefit tenant i’ll ever take on. The change in attitudes in the 25 years i’ve been renting is quite staggering.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302975#Comment_302975 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=302975#Comment_302975 Fri, 25 Aug 2023 11:14:23 +0100 CWatters Posted By: Artiglio
I built a block of 4 small flats in 2004 with the intention of renting , the first EPC came in at B’s all round , 10 years later they were all assessed as being very average C’s, with the varying news on energy efficiency and possible changes to the assessment i decided to lock in the C’s for 10 years in view of them all having had new gas boilers , uprated heating controls and ensured Led lights everywhere. So had the epc’s done again this year , 5 years early.
Now all good C’s not far from B’s but no practical/economic way to make the jump.

Had an EPC done on a flat last year. Built around 1980 I think. Old Electric Storage heaters, no gas. Was surprised to get a B.]]> EPC system changes https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=303043#Comment_303043 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17921&Focus=303043#Comment_303043 Wed, 30 Aug 2023 15:11:07 +0100 WillInAberdeen https://think.ing.com/articles/review-of-the-energy-performance-of-buildings-directive-major-renovations-ahead

In the EU, it looks like all EPCs will be re-graded, so that they use the same scale in all member states.

The new scale will be from A for a zero-energy building, through to G for the worst 15% of buildings. There may be an A+ for buildings that export energy.

Unlike in Scotland, it will be based on Primary energy use rather than on fabric heat losses. So adding a heat pump should improve the EPC in the EU. There are drawbacks to measuring 'primary' rather than actual energy use or CO2 though.

There will be targets that housing has to improve to EPC E and then D by certain dates, and to add solar.

They will introduce a lifecycle GWP measure to discourage high-carbon construction materials.]]>