Gaps and Disadvantages The BLCA represents an important part of these evaluation methods. Lots of previous studies have allowed the BLCA tools to be reviewed (Zabalza Bribián et al., 2009, Nibel et al., 2005, Haapio and Viitaniemi, 2008a, Erlandsson and Borg, 2003b). Nevertheless, there are some gaps regarding the environmental indicators, easily understandable presentation of the BLCA results to its users, simplification, and adaptation to various purposes or applications (e.g. early design phases) (Zabalza Bribián et al., 2009, Todd et al., 2001b). LCA was mainly developed for designing low environmental impact products. As products, buildings are special since: They have a comparatively long life They undergo changes often (especially offices and commercial buildings) They often have multiple functions They contain many different components They are locally produced They are normally unique are not often many of the same kind) They cause local impacts They are integrated with the infrastructure, system boundaries are not clear, etc. This implies that making a full BLCA is not a straightforward process as it is for many other consumer products (Zabalza Bribián et al., 2009). Both retrospective and prospective BLCAs have methodological limitations. In a retrospective BLCA, for example, there seems to be no general, objective basis for the definition of subsystems or the choice of allocation methods. In these respects, the retrospective BLCA methodology relies on the establishment of standards when a detailed standardisation of the methodology is required. An example of such a convention for this type of BLCA is the product-specific rules (PSR) in the Swedish system for EPD (PSR, 2001, PSR, 2000, Ekvall et al., 2005). The need for conventions is emphasised by the fact that the PSRs for different types of products do not have the same conventions for calculating the average data for electricity production (Ekvall et al., 2005).
Gaps and Disadvantages The BLCA represents an important part of these evaluation methods. Lots of previous studies have allowed the BLCA tools to be reviewed (Zabalza Bribián et al., 2009, Nibel et al., 2005, Haapio and Viitaniemi, 2008a, Erlandsson and Borg, 2003b). Nevertheless, there are some gaps regarding the environmental indicators, easily understandable presentation of the BLCA results to its users, simplification, and adaptation to various purposes or applications (e.g. early design phases) (Zabalza Bribián et al., 2009, Todd et al., 2001b). LCA was mainly developed for designing low environmental impact products. As products, buildings are special since: They have a comparatively long life They undergo changes often (especially offices and commercial buildings) They often have multiple functions They contain many different components They are locally produced They are normally unique are not often many of the same kind) They cause local impacts They are integrated with the infrastructure, system boundaries are not clear, etc. This implies that making a full BLCA is not a straightforward process as it is for many other consumer products (Zabalza Bribián et al., 2009). Both retrospective and prospective BLCAs have methodological limitations. In a retrospective BLCA, for example, there seems to be no general, objective basis for the definition of subsystems or the choice of allocation methods. In these respects, the retrospective BLCA methodology relies on the establishment of standards when a detailed standardisation of the methodology is required. An example of such a convention for this type of BLCA is the product-specific rules (PSR) in the Swedish system for EPD (PSR, 2001, PSR, 2000, Ekvall et al., 2005). The need for conventions is emphasised by the fact that the PSRs for different types of products do not have the same conventions for calculating the average data for electricity production (Ekvall et al., 2005).
Thesis-Modified-14-09-13.docx