# Calculating EPR where there are multiple BRUKLs

Where more than one BRUKL is produced forĀ a development, whichĀ is registered as a single assessment,Ā an area-weighted average should be used to calculate the number of creditsĀ toĀ be awarded. This does not apply where the āsimilar buildingsā approach is used.

Each of the energy performance outputs from the BRUKL (actual CO2/m2 notional CO2/m2 etc.) must be area-weighted to produce area weighted average values which are 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 BRUKL are available:

For building area A:

Notional building heating and cooling energy demand: 230 mJ/mĀ²

Actual building heating and cooling energy demand: 200 mJ/mĀ²

Notional building primary energy consumption: 300 kWh/mĀ²

Actual building primary energy consumption: 280 kWh/mĀ²

TER: 40 kg COā-eq/mĀ²

BER: 30 kg COā-eq/mĀ²

For building area B:

Notional building heating and cooling energy demand: 150 mJ/mĀ²

Actual building heating and cooling energy demand: 140 mJ/mĀ²

Notional building primary energy consumption: 200 kWh/mĀ²

Actual building primary energy consumption: 190 kWh/mĀ²

TER: 40 kg COā-eq/mĀ²

BER: 38 kg COā-eq/mĀ²

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/mĀ²

Actual building heating and cooling energy demand: 200*500/1000 + 140*500/1000 = 170 mJ/mĀ²

Notional building primary energy consumption: 300*500/1000 + 200*500/1000 = 250 kWh/mĀ²

Actual building primary energy consumption: 280*500/1000 + 190*500/1000 = 235 kWh/mĀ²

TER: 40*500/1000 + 40*500/1000 = 40 kg COā-eq/mĀ²

BER: 30*500/1000 + 38*500/1000 = 34 kg COā-eq/mĀ²

These area-weighted values are then used to calculate the overall EPRNC value.

`31/10/2018 KBCN clarified. Reference to EPRs and calculation example added`