EPC rating

[lizzie]

Really a question for those that have completed their sign off....what EPC rating did you get?

 

I have had a misunderstanding on SAP info assessor has worked from so result is not based on correct data  (i.e. one thing was that he said I had all electric heating and DHW when I have mains gas UFH, DHW and whole house MVHR). As far as I can see  Air tight does not tally with test or spec but I dont really understand that and window spec different (worse) and a few other things.

 

Based on inaccurate info it came out at B rating. I was disappointed at B even though I know the whole thing is skewed in favour of renewables (which I dont have)  but still think I should do better if he inputs accurate SAP data. Even if the rating ends up no better he still needs to sort out correct SAP data for my property and reassess on that basis.

 

Be interested to know what sort of ratings other have achieved.

Edited April 6, 2018 by lizzie

[Jeremy Harris]

Assessors pretty much never visit the build to see how it was actually constructed and what was used, so rely almost always on the information given to them by the builder.  In the case of a self-builder, much of that information comes from you, perhaps aided by technical data from those who've worked on the house construction.

 

In my case I did the design SAP and submitted that to building control, and didn't bother to use an assessor (seemed a waste of money at that stage, as I'd designed the house and had all the data).  For the "as built" SAP, just edited my design SAP worksheet to correct for the changes we'd made during the build (different windows and doors, different heat pump, different hot water system and different make and model of MVHR system).  Sadly the government have decreed that only a paid consultant can actually submit and lodge an as-built SAP report, so I emailed my FSAP file to an assessor and paidn him £100 +VAT to do nothing more than put his name and assessor number on it and lodge it on the government database.  He probably earned well over £200 an hour for his work - more than I charge insurance companies as a expert witness..............

 

You do need to take a LOT of care to make sure whoever does the as-built SAP has ALL the right information.  Key things for us were things like the near-complete absence of any thermal bridges, the absolutely correct as-built U values for the floor, walls and roof (pretty key this - you need to work them out as the air gaps for things like the service void make a difference), the actual heat loss rate for any hot water storage tank, making sure the measured air permeability is used if you've had an air test and got a chit, rather than the default value that SAP uses, checking that the make and model of your MVHR is correct in the worksheet, as that then pulls the right data from Appendix Q, and making sure that the correct Uw values have been entered for all the glazing, not some random assumption (this happens a fair bit - I've seen generic figures for 3G or 2G being used, rather than the true values from your window supplier).

 

If you make sure all this data is available to the assessor, then you should get a reasonable accurate result (not that it means much if  you've built to a better standard than building regs, as SAP falls over a bit when you get to very well insulated and air tight houses, I found).

 

Our SAP EPC came out at A107 and the SAP EI came out at A107 too.  It was totally bonkers, and not worth the paper it was written on, as this scanned snippet from the bottom of our EPC  show:

 

 

As an example of how bonkers this system is, lets assume that solar water heating cost the mid-point of the above cost, £5,000.  It would save £65 a year according to SAP, so the return on investment, excluding regular maintenance and component replacement cost, would be 76.9 years.........................

 

As for the suggestion we fit a wind turbine, when any idiot can tell from our post code on the certificate itself that we are in the bottom of a steep valley, then I'm afraid words fail me.  It just illustrates the mentality of the lunatics that came up with this scheme, IMHO.

 

As a final little gem, here's the bit from the EI part of the certificate (note that our CO₂ emission figure is actually negative):

 

 

I just love the line that reads "You could reduce emissions by switching to renewable energy sources", when we're already a negative CO2 "emitter", and have exceeded the "zero carbon home" target which was scrapped, anway (A100 would be zero carbon, anything above 100 is a "negative carbon" home).