Standards used in calculation

Together with the development of the directive, CEN has works with a package of EN standards which enable the implementation of the directives.

Energy use in buildings

For the calculation of overall energy use in buildings, CEN TR 15615 describes the setup of the standards.
  • EN 15603 defines the uses of energy that are taken into account and provides methods for assessing energy performance and energy ratings for new and existing buildings. 
  • EN 15217 sets out ways of expressing the energy performance in a certificate, and the ways of expressing the requirements of the energy performance.
  • EN 15459 provides a calculation method for the economics of heating systems involved in the energy demand and energy consumption of the building.

Thermal performance of the building envelope

For the calculation of thermal performance of building components, EN ISO 13789 is used to obtain the overall transmission heat loss coefficient.
The standards for U-values fall into two groups.
In the case of simplified methods, use:
  • EN ISO 6946 
  • EN ISO 13370
  • EN ISO 10077-1
  • EN 13947
In the case of detailed methods, use:
  • EN ISO 10211 
  • EN ISO 10077-2
Thermal bridges are covered in
  • EN ISO 10211 
  • EN ISO 14683
  • EN ISO 10456 is used to obtain the thermal values of building products.


For the calculation of ventilation and air infiltration
  • EN 15242 provides methods for the calculation of airflow rates. 
  • EN 13779 covers mechanically ventilated buildings, including those with air conditioning.
  • EN 15251 is used for indoor conditions.
  • EN ISO 15927 is used for climate data.

Domestic hot water

For the calculation of domestic hot water
  • EN 15316 is used, including both the specification of domestic hot water requirements and the calculation of the energy needed to provide it. 
  • EN 15241 is used for ventilation to determine the energy needed to supply and extract air, based on installed fan power and controls.
  • EN 15193 is used for lighting based on installed lighting power and annualised usage according to building type, occupancy and lighting controls.
  • EN 15232 is used for integrated building automation and controls.

Heating and cooling

For the calculation of heating and cooling
  • EN ISO 13790 defines two routes: simplified methods are based on monthly or hourly calculations and a simplified description of the building in terms of U-values. The inputs to these calculations are obtained using the standards below. 
  • For detailed numerical calculations, EN 15265 provides criteria together with tests for the validation of computer software. The choice of the applied calculation method is made at the national level.

Delivered energy

For the calculation of delivered energy for space heating
  • EN 15316 is used for losses and control aspects. 
  • EN 15377 is used for embedded systems.
  • The input to the calculation is the result of EN ISO 13790 using either a simplified method or a dynamic simulation.
  • EN 15243 is used for space cooling.

Monitoring and verification

For the monitoring and verification of energy performance, use the following standards.
  • EN 13829 Determination of air permeability of buildings - Fan pressurization method 
  • EN ISO 12569 Determination of air change in buildings - Tracer gas dilution method
  • EN 13187 Qualitative detection of thermal irregularities in building envelopes - Infrared method
  • EN 15378 Inspection of boilers and heating systems
  • EN 15239 Energy performance of buildings - Guidelines for the inspection of ventilation systems
  • EN 15240 Energy performance of buildings - Guidelines for the inspection of air conditioning systems