18. Energy savings calculations

Energy savings are calculated either before (ante) or after (post) implementation.

Before carrying out an energy-saving action, a calculation will be made to assess the operation's profitability and feasibility: the result will be based on an estimated calculation (ex ante).

This calculation is mandatory in the case of an energy audit or diagnosis, where each recommendation for improving energy performance and reducing energy consumption must be accompanied by an estimate of energy savings and profitability (Ademe specifications, AFNOR normative document BP X 30 120 and European standard NF EN 16247).

The estimate is based on the elements in the appraiser's possession, using a more or less precise method. It is accepted that the margin of error should not exceed 25%.

The accuracy of this...