When conducting an LCA study, the practitioner is constantly confronted with figures: some are needed to specify a modelling parameter; others are needed as cross-references, or benchmarks for comparison purposes. Such numbers always depend on the context of a study, and are generally not globally valid, which is why this guidance does not specify the use of predefined default values.
For numerous studies, however, average or default values may be helpful, and have the potential to significantly reduce the effort for data collection, especially if the relevant figures are required, yet are not critical for the study outcome. Also, to gain confidence in one’s study, the practitioner may use such values for cross-reference. For such purposes, a non-comprehensive collection of various default values is provided in this Annex. This collection of values does not claim to be ultimately right, and the practitioner has to decide by himself or herself whether the given values are applicable to the study’s context, and whether utilizing these values will be beneficial for the study.
Default Parameters for Building LCA