Through selling my mothers house I have had the amusement of seeing one of the new EPC certificates that every house must have when sold.
The results are "interesting". The inspector completely missed the fact that the house has a rather sophisticated zoned CH system controlled by more than one room thermostat (it does NONE/HW/UP/DOWN/BOTH).
It was described as partially double glazed and given 2 stars for that. In fact the only two windows that are not double glazed are in the kitchen and larder (where it serves to let heat escape intentionally).
The list of suggested improvements was in a very strange order (although a couple of them are correct this seems to be more by chance than anything else). Are EPCs sponsored by the companies selling home improvements? Or is it a case of poor training of inspectors?
Ranking them by the more sane measure of saving benefit to cost: annual saving cost Hot water tank insulation 24 24 Low energy lighting 30 25 Thermostatic radiator valves 35 350 Floor insulation 60 1000 Flat roof insulation 40 1000 New condensing boiler 65 3000 Solar water heating 40 4000 Double glazing throughout 50 6000 Solar PV on present FIT 260 8000
Of these I think the floor and flat roof insulation are good suggestions and replacing the double glazing which is near end of life would also be sensible. But the boiler is still quite new. I doubt that TRVs would give the benefit predicted since the zoning already shuts down the unoccupied parts of the house for most of the daytime.
The hot water tank is already very well insulated and the lights in the main parts of the house in regular use are already low energy lamps. Seldom used rooms still have original filament bulbs. The saving claimed is illusory (it is a classic 80/20 problem).
Solar water heating is a joke since the government subsidises you to dump the entire output of your solar PV system into the hot water immersion heater whilst still paying for "half" of the electricity.
A more practical problem is that the house has little or no suitable roof area for enough solar panels. The main roof area is north facing!
It also suggests why not get an exempted biomass boiler and contribute more smoke to air pollution in the city as a final parting shot. They also completely failed to notice that it still has an open fireplace (which could still be used if the chimney was swept first).