Operational carbon emissions calculation

Calculated carbon emissions are based on available data on energy consumption, water consumption, waste production, and fugitive gas emissions. All carbon emissions are displayed in CO₂ equivalents (kgCO₂ e or tCO₂ e) considering the Global Warming Potential of non-CO₂ greenhouse gases. The conversion of resource consumption data to carbon emissions is based on emission factors from different sources. For more information, see Emission factors.

All information on carbon emissions can be displayed using the location or market-based reporting approach affecting the emissions related to "green electricity" contracts and "green natural gas" contracts. The location-based approach applies the national average electricity emission factor (kgCO₂ e/kWh) as mandatory in all reporting standards. Currently, there is a default emission factor of zero for all green energy contracts when applying the market-based reporting approach and the applied emission factors for non-green contracts are the same as in the location-based approach.

Carbon emissions are calculated as follows:

Equation 6. 

G_{y,b,st,ghgn,r}=i_{st}\cdot O_{y,b,st}\cdot EF_{y,c,st',ghgn,r}

G_{y,b,st,ghgn,r} = Ghg emissions value for one year (y) in one building (b) for one resource subtype (st) and reporting type (r) of a particular emission factor scenario (ghgn)

r = reporting type (market-based or location-based)

st = resource consumption subtype (e.g., oil-based fuels)

i_st = Indicates if the emissions count positive or negative. For the subtype "Electricity self-generated and exported" i_st = -1 and therefore reducing the overall carbon emissions and for all other subtypes i_st = 1.

EF_{y,c,st',ghgn,r} = Emission factor associated with a given year (y) in a country (c) for one emission factor resource subtype (st') under a certain emission factor scenario (ghgn) sometimes associated with the reporting type (r)

O_y,b,st = Resource consumption for one year (y) in one building (b), and resource subtype (st)

If a building’s country exists in the country list of the emission factor table ( Emission factors ) the emission factor for the specific country is applied. If the building's country is not in the emissions factor table the global emission factor is applied to the calculation.

Carbon emissions for the different resource types are displayed under Sustainability | Resources and emissions. For more information, see Carbon emissions.

Electricity and heating

BuildingMinds takes the emission factors for electricity and heating directly from the CRREM Excel tool where available and applies the fixed ratio of heat and electricity emission factor in each country and year based on the UK 2018 ratio as it is done in the CRREM tool. Smaller adaptations to the latest actual developments have been done e.g. in Germany to better reflect the latest official figures as stated by public sources (German Umweltbundesamt). In this case, annual future changes of emission factors as found in the CRREM tool are applied to the latest available value from any other source, resulting in a similarly shaped decarbonization of future (grid) energy. At the moment, and in line with the CRREM tool, the same emission factors are applied for district cooling and district heating.

Find all emission factors in section Emission factors.

Emission factors for natural gas and heating oil are assumed constant over time and are based on the IPCC Emission Factor Database.

0.202 kgCO2e/kWh (IPCC Emission Factor Database, “Natural gas”)

0.266 kgCO2e/kWh (IPCC Emission Factor Database, ‘Gas/Diesel oil‘).

Water

BuildingMinds differentiates several categories of water supply and discharge. The sub-classification as either “water withdrawal” or “sustainable supply” is only for informational purposes and has no impact on the calculation of water-related carbon emissions. Emissions are calculated based on 2020 UK Government conversion factors for company reporting of greenhouse gas emissions sourced from the UK Department for Energy Security & Net Zero and the UK Department for Business, Energy & Industrial Strategy. The calculations differentiate water supply (0.344 kgCO₂ e/m³ ) and water disposal (0.708 kgCO₂ e/m³ ). The common usage of fresh water from municipal water supply contributes to both, water supply and water disposal, resulting in a total emission factor of 1.052 kgCO₂ e/m³ for this category. The same applies to water usage labeled as “unspecified” following a worst-case assumption. Groundwater, collected rainwater as well as reclaimed (“grey” or “black”) water only accounts for the 0.708 kgCO₂ e/m³ related to water disposal.

Waste

BuildingMinds uses the waste categories aligned with the terminology of the GRESB benchmarking. Emissions are calculated based on 2020 UK Government conversion factors for company reporting of greenhouse gas emissions sourced from the UK Department for Energy Security & Net Zero and the UK Department for Business, Energy & Industrial Strategy. At the moment, these factors are applied for all years of waste production. See the currently applied emission factors for the waste categories in the following table.

Fugitive emissions

BuildingMinds bases the conversion of certain amounts of non-CO₂ gas emissions into carbon equivalents on the global warming potential (GWP 100) indicated in the 5th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).