A method of operating a heating system including heating arrangements in at least two accommodation units of a building, said method comprising the steps of: supplying fluid energy medium (10, 31) to the heating system by a fluid energy medium supplier, detecting a representation of energy consumed in the building from the delivered fluid energy medium with a main meter as detected main meter values, and transmitting the detected main meter values to a central data storage, detecting a further representation of energy consumed in the building from the delivered fluid energy medium with at least one additional main meter as detected additional main meter values (AMMV) and transmitting the detected additional main meter values to at least one backend computer system, receiving detected main meter values from the central data storage in said backend computer system for allocation and/or correlation of the detected additional main meter values (AMMV) or derived representations of said detected additional main meter values, detecting a representation of energy consumed in each of said accommodation units from the delivered fluid energy medium with heat cost allocators or heat meters as detected allocation values and transmitting the detected allocation values to said backend computer system and/or central data storage, establishing main meter heat consumption values (MMHCV) for said accommodation units based on said detected allocation values and said detected main meter values, establishing additional main meter heat consumption values (AMMHCV) for said accommodation units based on said detected allocation values and said detected additional main meter values (AMMV) and reporting said main and additional heat consumption values (27, 28) to said accommodation units where the reporting frequency f rep,additional of said additional main meter heat consumption values (AMMHCV) is different from the reporting frequency f rep,main of said main meter heat consumption values (MMHCV). supplying fluid energy medium (10, 31) to the heating system by a fluid energy medium supplier, detecting a representation of energy consumed in the building from the delivered fluid energy medium with a main meter as detected main meter values, and transmitting the detected main meter values to a central data storage, detecting a further representation of energy consumed in the building from the delivered fluid energy medium with at least one additional main meter as detected additional main meter values (AMMV) and transmitting the detected additional main meter values to at least one backend computer system, receiving detected main meter values from the central data storage in said backend computer system for allocation and/or correlation of the detected additional main meter values (AMMV) or derived representations of said detected additional main meter values, detecting a representation of energy consumed in each of said accommodation units from the delivered fluid energy medium with heat cost allocators or heat meters as detected allocation values and transmitting the detected allocation values to said backend computer system and/or central data storage, establishing main meter heat consumption values (MMHCV) for said accommodation units based on said detected allocation values and said detected main meter values, establishing additional main meter heat consumption values (AMMHCV) for said accommodation units based on said detected allocation values and said detected additional main meter values (AMMV) and reporting said main and additional heat consumption values (27, 28) to said accommodation units where the reporting frequency f rep,additional of said additional main meter heat consumption values (AMMHCV) is different from the reporting frequency f rep,main of said main meter heat consumption values (MMHCV).