The transport emissions (A4) are calculated based on material masses for all data input rows. The default profiles vary based on the parameter selection and standards.
The generic calculation for A4 follows one of the below formulas:
A4 = material or product mass (a) x transport distance (b) x [carbon conversion factor outward (
if empty return trip from construction site is included:
A4 = material or product mass (a) x transport distance (b) x [carbon conversion factor outward (c1) + (empty running factor x carbon conversion factor return (c2))]
Emissions data for different transportation methods can be viewed in the data cards similarly to material resources and other data points in the One Click LCA database. Data cards are available in the 'Building materials' query for each tool that allows manual adjustments of transportation data.
When the transportation method dropdown menu is open, click on the green question mark to open the data card. You can find the data source under 'Datapoint background information' tab and the breakdown of environmental impacts under 'Environmental profile' tab.
All transportation data is declared per tonkm or tonmile; e.g. kilograms of CO2 equivalent per ton of material transported per kilometer or mile. Impacts of other than global warming potential are shown in tools where results are presented for multiple impact assessment categories (e.g. LEED, BREEAM).