|Aspect||B-12 Robustness of data (LCA, service life) to model the life cycle of a building product|
||How representative is a production process for a product?|
related study objective
|☒ stand-alone LCA||☒ comparative assertion|
related study phase
|goal and scope definition||inventory analysis (LCI)||impact assessment (LCIA)||interpretation||reporting|
|new buildings||existing buildings||construction products||screening LCA||simplified LCA||complete LCA|
|Provisions||In line with harmonized standards or technical approvals.|
||LCA studies may be conducted on a specific manufacturer’s product, in which case the use phase for that specific product can be considered, and service life data be generated in line with the relevant parts of ISO 15686.Where an LCA for an average product is being developed, the use phase may be harder to define robustly, owing to the variation in the use scenarios and application in the building, as well as in the products. It may be relevant to determine different use phase scenarios based on performance criteria for the products, although if this is associated with different manufacturing impacts (±10% for key environmental indicators), the product types should not be considered as a single average group.EN 15804 requires that, where an EPD is produced from more than one product’s data, the variance from the mean data reported in the EPD should be described in the project report for the verifier. Variance could be reported using the coefficient of variation or the standard deviation.
Some EPD programmes may have specific rules limiting the variance from the mean LCIA results for EPD covering a range of products, meaning that results must be reported for smaller groups of products with similar performance.
For simplified and screening LCAs, generic service life data can be used. For complete LCA, the service life for the specific product should be considered. Generic service life data are provided in various sources, including e.g. the national databases of different countries. It is recommended that practitioners refer to the service life data used in the context of the respective LCA study.