This European Standard is part of a series of standards on the method for calculation of system energy requirements and system efficiencies of space heating systems and domestic hot water systems. This standard (EN 15316 4 1) specifies: - required inputs; - a calculation method; - resulting outputs; - a method to take into account the energy performance of heat generation devices based on fuel combustion; for space heating generation by combustion sub-systems (boilers, biomass), including control. This standard specifies methods for the calculation of: - thermal losses from the heating and the domestic hot water generation system; - recoverable thermal losses for space heating from the heating and the domestic hot water generation system; - auxiliary energy of the heating and the domestic hot water generation systems. This standard specifies the energy performance calculation of water based heat generation sub-systems including control based on combustion of fuels (\'boilers\'), operating with conventional fossil fuels as well as renewable fuels. This standard does not cover sizing or inspection of boilers. This standard is also applicable to heat generators for heating or for combined service as domestic hot water, ventilation, cooling and heating. Generators for domestic hot water only are taken into account into part M8-8. This European Standard is the general standard on generation by combustion sub-systems (boilers, biomass) and is also intended for generation for domestic hot water production and/or space heating. These values are input data for calculation of the overall energy use according to EN ISO 52000 1 and EN 15316 1. Table 1 shows the relative position of this standard within the set of EPB standards in the context of the modular structure as set out in EN ISO 52000 1. NOTE 1 In CEN ISO/TR 52000 2 the same table can be found, with, for each module, the numbers of the relevant EPB standards and accompanying technical reports that are published or in preparation. NOTE 2 The modules represent EPB standards, although one EPB standard may cover more than one module and one module may be covered by more than one EPB standard, for instance a simplified and a detailed method respectively. See also Clause 2 and Tables A.1 and B.1.