1.When calculating cost-optimal levels of minimum energy performance requirements for buildings and building elements, Member States shall apply the comparative methodology framework laid down in Annex I to this Regulation. The framework prescribes calculation of cost-optimal levels for both macroeconomic and financial viewpoints, but leaves it up to the Member States to determine which of these calculations is to become the national benchmark against which national minimum energy performance requirements will be assessed.
2.For the purpose of the calculations, Member States shall:
(a)take as a starting year for the calculation the year in which the calculation is being performed;
(b)use the calculation period in Annex I to this Regulation;
(c)use the cost categories in Annex I to this Regulation;
(d)use for carbon costing as a minimum lower bound the projected ETS carbon prices as given in Annex II.
3.Member States shall complement the comparative methodology framework by determining for the purpose of the calculations:
(a)the estimated economic lifecycle of a building and/or building element;
(b)the discount rate;
(c)the costs for energy carriers, products, systems, maintenance cost, operational costs and labour costs;
(d)the primary energy factors;
(e)the energy price developments to be assumed for all energy carriers taking into account the information in Annex II to this Regulation.
4.Member States shall endeavour to calculate and adopt cost-optimal levels of minimum energy performance requirements in relation to those building categories where so far no specific minimum energy performance requirements exist.
5.Member States shall undertake an analysis to determine the sensitivity of the calculation outcomes to changes in the applied parameters, covering at least the impact of different energy price developments and the discount rates for the macroeconomic and financial calculations, ideally also other parameters which are expected to have a significant impact on the outcome of the calculations such as price developments for other than energy.