How to specify unit, mass and conversion factors for a building product
Purpose
Section titled “Purpose”Specify the declared unit and the mass correctly for a building product, and optionally let the building product be used in the building model in units other than the one the EPD is declared in.
Prerequisites
Section titled “Prerequisites”Declared unit and Mass per decl. unit are specified in step 2 (Details) of the wizard for a new building product of the type Building material. Conversion factors can only be added afterwards, on the building product’s detail page in edit mode.
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Choose Declared unit based on the EPD: kg, m, m², m³ or pcs. The emission data in step 3 (Emissions) must correspond to this unit.
If the EPD’s data is given in a unit other than these five, for example per 1000 kg, you have to convert the emission values to the chosen unit yourself before entering them in step 3. There is no separate field for that conversion.
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If the declared unit is not kg, enter Mass per decl. unit: the weight in kg per declared unit. Often read as mass or density in the EPD. A plasterboard with the unit m² can for example have a mass of 10 kg/m².
If you choose kg as the declared unit, the mass is automatically set to 1 and can be changed if the EPD is given per a kg figure other than 1.
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If the building product needs to be insertable into the building model with a unit other than the declared one, for example a building product declared per kg that should be inserted as m² in a construction, add a Conversion factor on the building product’s detail page: choose the desired unit, and specify how many of the declared unit one of the new unit corresponds to (for example “1 m² → 12 kg”). Without a conversion factor, the building product can only be used in the declared unit.
Result
Section titled “Result”The building product’s emissions are calculated correctly from the declared unit and the mass. If you have added conversion factors, the building product can also be selected in the extra units when it is inserted into a construction.