RICS WLCA Uncertainty Factor Tool
This tool is intended to assist with the whole life carbon assessment uncertainty factor calculation, based on the methodology detailed in the RICS Whole Life Carbon Assessment for the Built Environment Professional Standard (2nd edition).
Enter the required information into the yellow fields. When done, the results will appear/update in the green field. Care should be taken in selecting the ten products – see the RICS methodology for this.
| 1. Contingency factor | |||
| Enter the project stage to get the contingency factor. | |||
| Project stage | |||
| Result (%) | |||
| 2. Carbon data uncertainty factor | ||
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Enter details for the ten most impacting products:- 1. The percent of the building's embodied carbon emissions (A-C excl. B6-8) due to the product (total quantity installed). E.g. if the building's total emissions are 1,000,000kg CO2eq. (A-C excl. B6-8) and of that the total emissions due to the product are 10,000 kg CO2eq. then enter 1%. 2. Six carbon data quality scores, based on the EPD/LCA data used for the product and according to the RICS WLCA methodology. Note that some may have a max. score less than 10. |
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| Product | % of building emissions A-C excl. B6-8 (W) | Geography | Technology | Product Specificity | Temporal | Granularity | Verification | Score (S) | Weighted Score (Ws = S x W) | ||
| 1 | 0 | 0 | |||||||||
| 2 | 0 | 0 | |||||||||
| 3 | 0 | 0 | |||||||||
| 4 | 0 | 0 | |||||||||
| 5 | 0 | 0 | |||||||||
| 6 | 0 | 0 | |||||||||
| 7 | 0 | 0 | |||||||||
| 8 | 0 | 0 | |||||||||
| 9 | 0 | 0 | |||||||||
| 10 | 0 | 0 | |||||||||
| Weighted average score (sum of Ws / sum of W): | |||||||||||
| Result (%) |
| 3. Quantities uncertainty factor | ||
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Enter details for the ten most impacting products:- 1. The 'Quantities Uncertainty Levels Score' (QUL score), based on the type of quantity data used for the product. |
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| Product | QUL score | Score (S) | Weighted Score (Ws = S x W) | ||
| 1 | 0 | 0 | |||
| 2 | 0 | 0 | |||
| 3 | 0 | 0 | |||
| 4 | 0 | 0 | |||
| 5 | 0 | 0 | |||
| 6 | 0 | 0 | |||
| 7 | 0 | 0 | |||
| 8 | 0 | 0 | |||
| 9 | 0 | 0 | |||
| 10 | 0 | 0 | |||
| Weighted average score (sum of Ws / sum of W): | |||||
| Result (%) |
| WLCA uncertainty factor | ||
| Result (%) | ||
Note that the RICS methodology states that “the carbon data confidence scores/QUL scores for all key products are then averaged, weighted by their embodied carbon impact…”. The intention here isn’t totally clear and we can find no worked examples. Our interpretation is that a weighted average approach should be used – see the formulae in parentheses in the tables above.