Danish Sector Guide for Calculation of the Actual Energy Consumption

Energy calculations have for a long time been a controversial topic as building owners do not necessarily achieve the promised energy savings after a building upgrade, but is this due to incorrect calculations or rather the evidence of misunderstandings in the communication?

In Denmark, the innovation network for sustainable construction, InnoBYG started work on a Danish sector guide for the calculation of actual energy consumption in relation to upgrading of buildings. The focus was to make a common guide for energy calculations that can be used by consultants performing calculations. The guide should help to ensure more uniformity in calculations. Furthermore, the aim was to highlight the influence of uncertainties related to the calculation. This should ensure a transparent and comparable communication of the calculation assumptions, the result and the associated uncertainty of the energy calculation for building owners and developers.

This paper describes the process that leads to the sector guide and briefly explains the content in both the technical guide and the communication paper. Finally the paper discusses some of the known dilemmas related to the measured energy consumption compared with the estimated energy demand by calculation. The paper concludes that the result of an energy calculation should not be given as a single figure but rather as a spread between the best and worst case for the assumed conditions. Finally, a brief update on current actions is given related to the sector guide for calculation of actual energy consumption.

Keywords – Energy calculations, actual energy consumption, energy perfomance