The different CEN approaches for calculating the energy use for heating and cooling

The assessment of a building energy performance includes the energy use for heating, cooling, ventilation, humidification, dehumidification, hot water and lighting. The starting point is typically the determination of energy needs. This paper introduces several calculation procedures for calculating the building energy need for heating and cooling, applying the CEN standards to support the EPBD. The two basic types, differentiated by the time steps used in the calculation, are the quasi-steady-state and the dynamic method. In addition, interactions between buildings and the systems they contain can be accounted for either by the holistic or the simplified approach. Detailed descriptions and explanations are given in EN ISO 13790, concerning the energy need for heating and cooling, and in EN 15603, concerning overall energy use.