|Aspect||B-05 Products within complex systems|
||When does a product need to be considered within the context of a system (e.g. an energy storage or energy-generating 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||A product needs to be considered within the context of a system whenever it is part of the system that provides the overall product’s function, i.e. part of the object of assessment.The assessment of one individual product is not sufficient if the product’s function is given only within a more complex system. Then the entire system has to be assessed; the impacts of the product can be calculated from comparison with a reference scenario without the product’s function if this is possible, or else with an alternative state-of-the-art solution.|
||LCAs can be undertaken for products, collections of products grouped into components (such as a door, cladding system or heating system), collections of products grouped into building elements such as an external wall or roof, for prefabricated parts of buildings such as ‘bathroom pods’ or temporary accommodation, and for construction processes such as cleaning or demolition.EN 15804 has been written to allow EPDs for any of these products, components, elements or parts of building or construction processes to be compatible, because they are built up from ‘information modules’ for products and construction processes in a logical and consistent way.
An LCA dataset for a precast concrete panel could be built up from LCA datasets for cement, aggregate, reinforcement, concrete additives etc. An LCA dataset for a cladding system could be built up from LCA datasets for float glass and aluminium extrusion etc. The gate-to-grave sections of the LCA dataset can be developed with more certainty, as the use stage of the LCA dataset can be defined more specifically in a building. This is linked to the aspect G-06 (Distinction between the declared unit and the functional unit’).
The gate-to-grave modules of an EPD for a precast concrete floor panel can be much more specific, because its typical use can be envisaged much more clearly, and any defined scenario is more likely to be applicable.
The same principle applies for products and components that are part of a greater energy supply system. If their function can only be addressed adequately if the overall system’s function is assessed, then the entire system should be part of the object of assessment and be accounted for.