Green Star FAQs
Why were normalisation factors introduced in Green Star Buildings v1 for the Life Cycle Impacts credit?
This FAQ was updated on 04/07/2025 to include updated guidance on EN 15804+A2.
Normalisation was introduced in Green Star Buildings for the Life Cycle Impacts credit following extensive consultation with our Expert Reference Panels and Advisory Groups. Normalisation scales the impact category results according to the global availability of that resource or magnitude of environmental impact. As a credit that intends to help project teams make informed decisions based on the whole-of-life impact of a building, the normalisation factors assist in scaling the importance of the impact categories and improves the meaningfulness of a project team's decision within the global context.
The normalisation factors were calculated by our technical consultant using scientific methods and units that are used by EN 15804+A1 compliant Environmental Product Declarations (EPDs). Normalisation factors for EN 15804+A1 and EN 15804+A2 are outlined below, and can also be found in the Life Cycle Impacts Calculator available on the resources portal.
| EN 15804+A1 | |||
| Impact category | Units | Normalisation factor | Weighting factor |
| Climate change | kg CO2 equivalent | 6.96E+03 | 25% |
| Net use of fresh water | m3 | 2.67E+02 | 25% |
| Stratospheric ozone depletion potential | kg CFC 11 equivalent | 4.75E-02 | 0% |
| Acidification potential of land and water | kg SO2 equivalent | 3.87E+01 | 10% |
| Eutrophication potential | kg PO4 equivalent | 1.37E+01 | 10% |
| Photochemical ozone creation potential | kg C2H4 equivalent | 3.44E+00 | 10% |
| Mineral depletion (Abiotic Depletion Potential) | kg Sb equivalent | 6.27E-02 | 10% |
| Fossil fuel depletion (Abiotic Depletion Potential) | MJ net calorific value | 1.47E+06 | 10% |
| EN 15804+A2 | |||
| Indicator - Impact category / Resource Use | Units | Normalisation factor | Weighting factor |
| Climate change - total | kg CO2 equivalent | 7.60E+03 | 25.00% |
| Stratospheric ozone depletion potential | kg CFC 11 equivalent | 5.18E-02 | 0.00% |
| Acidification potential of land and water | mol H+ equivalent | 5.55E+01 | 3.33% |
| Eutrophication, marine | kg N equivalent | 1.95E+01 | 3.33% |
| Eutrophication, freshwater | kg P equivalent | 1.61E+00 | 3.33% |
| Eutrophication, terrestrial | mol N equivalent | 1.77E+02 | 10.00% |
| Photochemical ozone creation potential | kg NMVOC equivalent | 3.77E+01 | 10.00% |
| Resource use, minerals and metals | kg Sb equivalent | 6.36E-02 | 10.00% |
| Resource use, fossils | MJ net calorific value | 2.06E+06 | 10.00% |
| Net use of fresh water | m3 | 2.67E+02 | 25.00% |
This FAQ is related to the following Rating Tools, Categories or Credits:
- Green Star Buildings v1 / Positive / 26 Life Cycle Impacts
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