Where more than one NCM output is produced for a development, which is registered as a single assessment, an area-weighted average should be used to calculate the number of credits to be awarded. This does not apply where the ‘similar buildings’ approach is used.
For for projects in England assessed under UKNC V6.0, please see KBCN1618
Projects assessed under UKNC V6.1 can upload multiple BRUKL.inp files for a single assessment and the platform will perform the calculation. See KBCN1618
Each energy performance output from the NCM output (actual CO2/m2 notional CO2/m2 etc.) must be area-weighted to produce area-weighted average values entered into the scoring and reporting tool. When applying this method, please include your area-weighting calculations and outputs as supporting evidence.
The following provides an example of an area-weighting calculation for two building areas A and B, each of 500m2, for which separate NCM outputs are available:
For building area A:
Notional building heating and cooling energy demand: 230 mJ/m²
Actual building heating and cooling energy demand: 200 mJ/m²
Notional building primary energy consumption: 300 kWh/m²
Actual building primary energy consumption: 280 kWh/m²
TER: 40 kg CO₂-eq/m²
BER: 30 kg CO₂-eq/m²
For building area B:
Notional building heating and cooling energy demand: 150 mJ/m²
Actual building heating and cooling energy demand: 140 mJ/m²
Notional building primary energy consumption: 200 kWh/m²
Actual building primary energy consumption: 190 kWh/m²
TER: 40 kg CO₂-eq/m²
BER: 38 kg CO₂-eq/m²
Area-weighted values for building areas A and B (of total floor area 1000m2):
Notional building heating and cooling energy demand: 230*500/1000 + 150*500/1000 = 190 mJ/m²
Actual building heating and cooling energy demand: 200*500/1000 + 140*500/1000 = 170 mJ/m²
Notional building primary energy consumption: 300*500/1000 + 200*500/1000 = 250 kWh/m²
Actual building primary energy consumption: 280*500/1000 + 190*500/1000 = 235 kWh/m²
TER: 40*500/1000 + 40*500/1000 = 40 kg CO₂-eq/m²
BER: 30*500/1000 + 38*500/1000 = 34 kg CO₂-eq/m²
These area-weighted values are then used to calculate the overall EPRNC value.
20 Sep 2023 - Minor corrections, applicability to INC V6 confirmed and cross-reference to UKNC V6 guidance added. 14 Jun 2023 - Note added to confirm this is integrated into the platform for UKNC V6.1 in all countries. 24 Aug 2022 - Note added to confirm this is N/A to UKNC V6 for projects in England 07 Feb 2022 - Reference to 'BRUKL' amended to 'NCM output' to clarify for non-UK assessments 31 Oct 2018 KBCN clarified. Reference to EPRs and calculation example added
