The EPC is based on averages and ignores actual occupancy and usage. I also produces an average house rating - band D in England and Wales. My EPC has rted our uninsulated, partially heated solid walled Victorian villa as G1/G18. It tells me that of I complete all of the energy performance measures recommended I can achieve E47/E52. Since this is below average I lose out on FIT payments. What is worse the measures recommended include one which would be illegal in our conservation area and potentially harmful to the house, wind power. The measures do not include Biomass GSH or ASH. Is the methodology at fault or the assessor? Surely if I move to renewables instead of installing the upgraded LPG boiler my rating could be higher than that stated.