EPC for RHI with incomplete build

[oranjeboom]

Still considering my heating options (see here) and looking at the RHI on an ASHP, I see that I need to get a new EPC as the other one I have is more than 2yrs old and the rating at the end of the highly useful report? tells me it an ' E' (46). So I would need to get a new assessment done before I have the ASHP fitted (should I indeed go that route). If I do decide to go down the ASHP route, then I want to get that installed at the same time as all the rest of the plumbing systems and not have the mess/extra labour visits/costs to fit an ASHP after the house is 'complete'.

 

As of today, I have a shell of a house still. Would they still be able to undertake an assessment? Windows and doors in, so that'll be a tick for the 'doubled glazed' box on the assessor's sheet and I get a gold star for the panels on the roof. But I have no heating, the loft is bare (no insulation), old crappy CWI is mostly gone, so my efficiency rating would probably be closer to an F than an D! In terms of the RHI, that appears to be based on the total heat demand - but how is that assessed if I have no heating installed yet? Do I just inform the assessor that I will be fitting UVC/ST/Sunamp/re-instating the old oil boiler?

[A_L]

6 hours ago, oranjeboom said:

 

As of today, I have a shell of a house still. Would they still be able to undertake an assessment? Windows and doors in, so that'll be a tick for the 'doubled glazed' box on the assessor's sheet and I get a gold star for the panels on the roof. But I have no heating, the loft is bare (no insulation), old crappy CWI is mostly gone, so my efficiency rating would probably be closer to an F than an D! In terms of the RHI, that appears to be based on the total heat demand - but how is that assessed if I have no heating installed yet? Do I just inform the assessor that I will be fitting UVC/ST/Sunamp/re-instating the old oil boiler?

 

Since it is an existing house I think an assessment could be done on the basis of electric instantaneous heating.

 

However the heating system does not affect the total heat demand, which is dependent on the heat losses.   IIRC if the EPC has recommendations the heat demand figure for the RHI payment will be based on the heat demand with the recommendations implemented. If you have <= 150mm loft insulation then 270mm will be recommended and if no CWI this will be recommended, if <80mm jacket on DHW cylinder then improvement also recommended. There may be other relevant recommendations.

[Trw144]

I believe the 270mm loft insulation and cwi (if possible) is a requirement needed before they will accept your application.

[oranjeboom]

 

 

10 hours ago, A_L said:

Since it is an existing house I think an assessment could be done on the basis of electric instantaneous heating.

I'll phone a local EPC assessor today to see what they say.

 

10 hours ago, A_L said:

However the heating system does not affect the total heat demand, which is dependent on the heat losses.   IIRC if the EPC has recommendations the heat demand figure for the RHI payment will be based on the heat demand with the recommendations implemented. If you have <= 150mm loft insulation then 270mm will be recommended and if no CWI this will be recommended, if <80mm jacket on DHW cylinder then improvement also recommended. There may be other relevant recommendations.

https://renewable-heat-calculator.service.gov.uk - playing around with that, the heat demand also appears to be determined by what the heat source is. Coal gives a higher figure than electric gas or oil. So maybe I should state that I am getting some grotty coal furnace to do the space heating and get a higher KWh rating!!

 

2 hours ago, Trw144 said:

I believe the 270mm loft insulation and cwi (if possible) is a requirement needed before they will accept your application.

Yes, the guidelines state that you need to have loft/CWI if that is a recommendation ("If loft and/or cavity wall insulation is recommended in your EPC, you must install it and then get a new EPC. Your new EPC must reflect your newly insulated home": https://www.ofgem.gov.uk/system/files/docs/2017/10/essentialguideforapplicants_rpiia_4.1_october_2017.pdf) so I may as well sort out the loft roll before any assessment takes place and get some evidence that I will have EWI at some point (or forget to mention to the assessor that most of the CWI was taken out!).

[A_L]

54 minutes ago, oranjeboom said:

 

https://renewable-heat-calculator.service.gov.uk - playing around with that, the heat demand also appears to be determined by what the heat source is. Coal gives a higher figure than electric gas or oil. So maybe I should state that I am getting some grotty coal furnace to do the space heating and get a higher KWh rating!!

 

Yes, the guidelines state that you need to have loft/CWI if that is a recommendation ("If loft and/or cavity wall insulation is recommended in your EPC, you must install it and then get a new EPC. Your new EPC must reflect your newly insulated home": https://www.ofgem.gov.uk/system/files/docs/2017/10/essentialguideforapplicants_rpiia_4.1_october_2017.pdf) so I may as well sort out the loft roll before any assessment takes place and get some evidence that I will have EWI at some point (or forget to mention to the assessor that most of the CWI was taken out!).

 

The link does appear to make an allowance for the efficiency of converting input fuel to output heat but I am sure that the RHI payment is only based on the energy provided by e.g. the ASHP to heat  the house i.e. the previous system is disregarded. It may be that a coal house, with a chimney, is draughtier and thus is assessed as taking more to energy to heat.

 

Because you have a cavity wall the EPC will not have a EWI recommendation. Even if you had a solid wall and it recommended EWI this recommendation is disregarded for RHI purposes