Defra has said that it will add a climate correction factor (CCF) to the R1 energy-from-waste (EfW) accreditation formula on 31 July.
It said there will be no effect on EfWs in England and Wales because the EU legislation aims at levelling the playing field for countries in warmer climates.
The department received three responses to a consultation on the change, which ran in January.
Two of these raised concern that the data required to determine whether a plant was eligible for CCF would not exist at many sites.
It was suggested that further consideration had to be given to this, and perhaps the nearest official recording weather data station used, until there was 20 years of robust data at the actual site.
Defra said the data may be available commercially but, if not, the regulator could accept information from the nearest recording weather data station.
Facilities looking to import waste need R1 accreditation to be classified as an energy recovery facility but the UK does not currently import refuse-derived fuel.