# Commission Delegated Regulation (EU) No 244/2012 of 16 January 2012 supplementing Directive 2010/31/EU of the European Parliament and of the Council on the energy performance of buildings by establishing a comparative methodology framework for calculating cost-optimal levels of minimum energy performance requirements for buildings and building elements (Text with EEA relevance), Division (2): Global costs for buildings and building elements shall be calculated by summing the different types of costs and applying to these the discount rate by means of a discount factor so as to express them in terms of value in the starting year, plus the discounted residual value as follows:

Extent: E+W+S+N.I.

C g τ = C I + Σ j Σ i =1 τ C a,i j × R d i – V f,τ j where:
τ means the calculation period
Cg(τ) means global cost (referred to starting year τ 0) over the calculation period
CI means initial investment costs for measure or set of measures j
Ca,I (j) means annual cost during year i for measure or set of measures j
Vf,τ (j) means residual value of measure or set of measures j at the end of the calculation period (discounted to the starting year τ 0).
Rd (i) means discount factor for year i based on discount rate r to be calculated
as:
R d p = l l + r /100 p where p means the number of years from the starting period and r means the real discount rate.

---
Source: https://www.legislation.gov.uk/eur/2012/244/annex/I/division/4/division/4.3/division/2 (the official version)
Page: https://openlegislation.uk/eu-regulation-2012-244/annex-I/division-4/division-4.3/division-2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.