Accounting for Re-used Materials

This feature allows users to account for reclaimed materials in the projects. Assigning of reused materials is currently enabled for limited tools. This feature is planned to be added to relevant tools within the future updates.

How can I use this feature?

Materials can be marked as reused on the right side of the material row in the building materials input query. Select the 'Reused material' checkbox for the desired building materials or elements.

Some tools also offer the option to account for locally reused materials, which will discount initial A4 impacts too.

How does this affect my calculations?

• Material manufacturing (A1-A3) and material wastage-related installation (A5) impacts are left out for the materials marked as reused, as these life cycle stages are accounted for in the scope of the building the materials were reclaimed from.
• Transportation impacts are calculated regardless of whether the material is reused or new. If the reused materials are reclaimed on site, set the transportation distance to zero.
• If the reused materials have a service life less than the calculation period of the assessment, material replacements are calculated as usual. Material replacements are always considered for new materials.

Sources for re-used materials calculations

The current system we have implemented is our interpretation, based on best practices and industry knowledge, of how material re-used can be calculated and applied to any material. 

There are two certifications which have their own approach to how re-used materials are calculated.

• MPG (Milieu Prestatie Gebouwen) in the Netherlands calculates material re-use with a multiplier. In their case they calculate the total emissions with a 0.2 (20%) multiplier which is applied to the A1- A3, C3, C4 and D stages of the product. Sources behind this method are unknown.
• Futurebuilt in Norway calculates material re-use with a multiplier. In their case they calculate the total emissions with a 0.2 (20%) multiplier which is applied to the A1-A3 emissions of the product. Sources behind this method are unknown.