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. ... mehrThe 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.