An increasing degree of digitalization in construction planning offers significant potential for building life cycle assessment (LCA) to reduce access barriers, as well as the assessment effort itself. To realize the widespread application of LCA tools and their potential to effectively minimize life cycle impacts, an open approach is required that allows for flexible application of comprehensive LCA studies and early integration in planning processes. The authors present an approach for LCA integration in all phases of digital planning which aims at a DGNB (Deutsche Gesellschaft für nachhaltiges Bauen) certification based on the open Building Information Modeling (BIM) standard Industry Foundation Classes (IFC). The approach takes into account varying levels of development and resulting data availability during integral planning phases, as well as resulting LCA application contexts. It goes beyond existing strategies and allows one to consider both BIM and LCA software through a workflow based on a single data format. The assessment framework is operationalized through standardized interface development and technical realization following the information delivery manual (IDM) process standardized for IFC interfaces. The Extensible Markup Language (XML) schema, as a specific implementation for certification, provides the target system for LCA data requirements and is generalized to a planning phase specific IDM base table. The technical realization based on respective model view definitions and distributed data suggests a pathway to the standardization of LCA-IFC integration based on an open approach. The overall approach exemplarily applies to the “LERNZENTRUM” at the Karlsruhe Institute of Technology (KIT) campus. We conclude that an open BIM approach for LCA integration in model-based planning is feasible, but requires several adjustments in IFC, LCA, and planning practice. Adding a lifecycle element to the IFC to connect BIM and LCA provides comprehensive feedback for informed decision making based on environmental impact.

Life cycle assessment (LCA) is the standard method for the quantification of environmental impacts within the construction sector, relying on available generic LCA databases. New developments, such as the increased influence of the building construction for LCA and the forthcoming of building information modeling (BIM), implicate new requirements on multiscale levels of development and complexity for LCA construction databases. At the example of the German “Ökobau.dat”, one of the leading LCA construction databases, this publication discusses whether the database is able to meet these requirements. The analysis shows the strengths of the Ökobau.dat with regard to standardization conformity (EN 15804, ILCD), data provision in machine-readable XML format, and the provision of an application programming interface. Shortcomings include incorrect linking of building life cycle inventory data with environmental information, incorrect documentation of functional units, missing generic datasets, the modeling of energy use data or the lack of a uniform structuring, or material classification. The authors propose solutions such as the provision of appropriate functional units, the implementation of a top-down approach to investigate the completeness of data based on existing nomenclatures or the extension with an appropriate material classification. This would allow for future viability and adaptability of Ökobau.dat for digital LCA.

Solving complex issues of energy-efficiency – at the building as well as urban level – requires a holistic, integrated approach. The energetic behavior of a system should not only be considered in individual processes or phases, such as operation. A holistic optimization should rather consider the explicit energy flows as well as the material fluxes including the associated gray energies over the entire system life cycle. The realization of such a holistic integral planning process implies an integrated planning-accompanying evaluation and optimization of the planned object. The early use of LCA tools and sustainable building assessment systems (SBA) provides an important basis for assessing planning decisions at a conceptual level for their impact on the entire lifecycle of a building and for ensuring good sustainability performance. In practice, however, it is currently evident that the non-standardized and inadequate connection of simulation and balancing tools (e.g. LCA) to BIM authoring tools and the resulting high time expenditure for data acquisition and LCA application counteracts with a targeted stronger penetration of the market. For realizing a consistent integral planning process – especially in early planning phases – an IFC-based interface is being developed for the connection of LCA tools to BIM models (data input) and the preparation and configuration of the LCA result data for the designated use in different SBA. In this contribution, from the interface specifications for different levels of granularity and concretization in the different planning phases that are developed by means of norm-based processes of model standardization in an underlying research project, parts regarding the early project stages will be presented.