Since the Regulations implementation in 2014, they were amended in 2020. The most significant change relates to how a heat supplier must achieve compliance with the regulations. These amendments introduced building classes, which now means that heat suppliers must define the class of each building on their network. There are three building classes stated within the Regulations, which are: Viable, Open and Exempt. The purpose of these building classes is that dependent upon which class a building falls into will determine if a heat supplier needs to install customer meters. Building classes also determine whether a cost-effective/technical feasibility analysis is required regarding the installation of customer meters within Open class buildings. In order for heat suppliers to have enough time to comply with these amendments, the Government introduced transitional arrangements, which came into force on the 27th of November 2020 and ended on the 1st of September 2022. These transitional arrangements have now ended; therefore, all heat suppliers should comply with the new changes introduced within the 2020 amendments.