This report describes the current operating environment of building life-cycle assessment (LCA) and Building Information Modelling (BIM) in the Nordic countries and Estonia. Also, findings on constraints and enablers for harmonising building LCA are discussed. The report explains the current enablers and hindrances for BIM-based building LCA in the Nordic countries and Estonia. The findings set the basis for further project work that guides BIM-based LCA and material declaration.
Nordic harmonisation of building LCA would allow the comparison of building LCA calculations between the Nordic countries and allow the Nordics to take an important role in harmonising building LCA around Europe. Harmonisation also helps the Nordic authorities better understand the impact, significance, and potential of buildings regarding the overall carbon emissions, and it thus helps the similar efforts of the Nordic authorities to prepare new regulations for limit values. The Nordic countries are among the most active users of BIM in Europe, and it is a field continuously developing with the digitalisation of the world. Harmonising the methods for BIM-based LCA calculations will benefit the Nordic construction sector, but this will not happen without facing some challenges.
The main benefit of using BIM in building LCA is that one can effectively get quantity information from a specific model, combine it with the emission data and, therefore, quickly evaluate the environmental performance of the chosen solution, together with other criteria for decision making.
In order to harmonise BIM-based LCA calculations, both LCA methods and BIM modelling have to be evaluated and further aligned. BIM can provide information on the materials and geometry depending on the level of detail in the model when the calculation is made. It is important to ensure that elements in the model are classified in a harmonised way. Although standards exist, these are not always adopted by the various actors within the construction industry. The models of the various design disciplines – structural, architectural, HVAC – should also be harmonised, especially as duplicate elements exist between the models.
Not all information needed for an LCA calculation of a building is available in a BIM. Additional information is required for calculating the carbon footprint in modules, such as the operational energy use, the transports and processes at the end of life. Some of the general values used for these purposes are based on the area of the building or, in some countries, gross area or heated area, which might be available in the model or acquired from elsewhere. There is a need to define, identify and harmonise the common building area concepts.
Thus far, national calculation guidelines and the national emission databases have enabled comparing building LCA results within each country. In the future, BIM could partly help automate building LCA calculation and reporting. However, data security needs to be taken into account, especially if uploading BIM in cloud-based BIM and LCA services. At least public owners have policies to secure data management and block leaks from unwanted actors. Data ownership is also an ongoing debate. IFC resolves some data-sharing issues as designers’ native authoring software-specific tools or additions are not included in the IFC file. However, the violation of design solution IPRs needs to be controlled in BIM-based LCA processes.