BIM for Building LCA - Enhancing Nordic Sustainable Construction Through Digitalisation

This BIM4LCA report provides a generic description of the BIM to LCA process, which can support calculating and reporting normative LCA in building construction projects. The project developed generic guidelines for reliable BIM-based material inventory (bill of materials), specifications for information needed for modelled building components, data transfer from BIM tools to LCA tools, and iterative design and analysis workflow between BIM and LCA tools. The guidelines target the architects, structural engineers, heating, ventilation, and air conditioning (HVAC) and electrical designers who create the BIM models and the LCA analysts who extract information from the models. The starting point for the guidelines has been that they require as small changes as possible to the current BIM modellers’ workflow. Locations for data in the models are recommended so the LCA analyst will receive material quantity information from the model, as designed by the architects and other designers, with reliable outcomes. Also, the level of detail in different stages of construction projects is recognised, and best practices for amending that information are recommended.

The BIM4LCA project produced two examples of buildings and their BIM models,
which can be used by practitioners architects, structural engineers, HVAC and
electrical designers and LCA analysts to learn how to do the modelling to support
BIM-based building LCA in practice. The buildings are designed according to the
Finnish Construction Act and building codes. The design principles have emphasised the life-cycle properties of buildings, e.g. in terms of multi-purpose usability, adaptability and access to natural light. The report provides links to the native architectural, structural, HVAC and electrical BIM models and their Industry Foundation Classes (IFCs) files, including their BIM specification documents and related material and product information. These files are provided for free with a Creative Commons license.

The project also created seven educational videos that support practitioners in
learning BIM-based building LCA. The videos explain how BIM model authors should do the modelling to support the LCA specialists in BIM-based quantity take-off and mapping of the result to the LCA calculation software . The videos are on the YouTube channel of the Nordic Sustainable Construction programme.

The BIM4LCA project suggests BIM data requirements and best practices for
modelling and data processing that can enhance the usability and accuracy of BIM data for LCA purposes. The project also recommends that Nordic authorities set BIM requirements for BIM modellers if a climate declaration is required and support information harmonisation in the construction sector. The project proposes a future vision of automated BIM-based LCA that can provide instant feedback and optimal solutions for low-carbon building design.

The results have been co-created by a consortium of VTT Technical Research Centre of Finland, Granlund, Gravicon and Insinööritoimisto Kallinen, and the Nordic partners: Sberesearch, Rangi Maja OÜ, Bengt Dahlgren Stockholm AB, Gravicon DK and Asplan Viak AS. The draft results have been communicated to the advisory board of the Nordic Sustainable Construction programme, and their comments and requests for changes have been considered. The draft BIM-based building LCA process was communicated to a broader public audience in a “BIM-Based Building LCA” webinar organised on the 12 th of December 2023, and the oral and written comments from the audience have been considered when finalising this report. The BIM4LCA working group has also participated and presented results in internal meetings with the sister tasks of the Nordic Sustainable Construction programme.