Energy savings according to the Energy Saving Ordinance (EnEV)
For the calculation of energy savings according to EnEV, standardised conditions are set. These are determined by the EnEV and the applicable standards (DIN V 18599-10, DIN V 4108-6, DIN V 4701-10). When comparing energy efficiency of different buildings, the “standard calculation” ensures that the same conditions are applied.
The results of the "standard calculation" can differ considerably from the real con-sumption values. The actual conditions differ from the standard conditions - for residential buildings, e.g., regarding:
- interior temperatures,
- exterior temperatures,
- ventilation, and
- consumption of domestic hot water.
If in case of an existing building input values for the calculation (such the exact U-value of the existing structure) are unknown, to a certain extent replacement assumptions may be used. Official bulletins are issued for this purpose. Calculating energy demand according to EnEV is carried out by specialised engineers or architects. These professionals use special calculation software and - as an additional feature - are also able to perform a realistic estimation of energy consumption and savings potential.