This report describes the current operating environment of building life-cycle assessment (LCA) and Building Information Modelling (BIM) in the Nordic countries and Estonia. It reports the findings on current building LCA and BIM practices and constraints and enablers for harmonising building LCA. It also provides an understanding of the enablers and hindrances for BIM-based building LCA in the Nordic countries and Estonia. This work sets the basis for further project work that provides guidance for BIM-based building LCA and material declaration.
The results reported have been produced by systematically collecting data via interviews and analysing information on BIM practices and normative LCA methods to define needs and constraints for further development activities in the project.
The Nordic countries have developed country-specific normative carbon footprint assessment methods based on EN15978 and EU Level(s) methods. There are still significant differences between the local methods concerning methodology aspects, such as system boundaries, life cycle scenarios, and reporting requirements, which, to some extent, prevent the harmonisation of building LCA reporting in the Nordics. Denmark, Norway and Sweden already have obligatory (i.e., normative) LCA calculations for new buildings, whereas Estonia, Finland, and Iceland plan to start requiring it soon.
As a whole, BIM can help low-carbon building design by supporting the comparison of alternative design choices in the initial phases of design by different design disciplines and thus supporting the finding of optimal solutions. BIM-based building LCA is here defined as a process where BIM provides adequate information on quantities to enable the formulation of a list of materials/products. This information is then linked with emission data. However, currently, inaccuracy in quantity take-off is an issue. The information content and identification of objects and materials in BIMs are not standardised, and therefore, project-specific knowledge is required in interpreting model data.
Integration with BIM software is another current challenge. BIM tools are widely used in the architecture and construction industry, but their seamless integration with LCA tools is still a work in progress. The lack of efficient interoperability between BIM and LCA software can result in increased time and effort, as practitioners may need to input data manually or make assumptions.