Four issues on the goal and scope definition of a BIM-based LCA study for existing buildings

Life Cycle Assessment is a standardised method for assessing the environmental impacts of products and services. With the European standard EN 15643 and the related EN 15978 regarding the environmental sustainability of buildings, LCA is also used in the construction field to assess the environmental impact of the buildings. In the literature, while simplifications of this methodology caused by the complexity of buildings are under research, especially in the early design stage, BIM-based LCA methodologies have emerged to support the simplification process and to gain applications automatism. Nevertheless, LCA's key aspects that guarantee the comparability and reliability of the applications are often underrated. This research investigates the issues in defining those key aspects with a review that combines technical standards, literature founding and international guidelines, giving also suggestions on what to consider when defining those aspects for the existing buildings’ refurbishment.