While disciplines such as architecture, structural design or technical building equipment have already integrated their processes, data structures and tools well into Building Information Modeling (BIM), this has not yet been sufficiently achieved in environmental planning and landscape architecture. Problems that make integration difficult arise from differences in the scope and scale of the models needed for building construction on the one hand and environmental planning on the other: while building construction models focus mainly on the structure itself, environmental planning also considers natural objects such as habitats and protected areas within a larger radius of the structure. Data about such objects are typically maintained in GIS, so the integration of BIM and environmental planning is a matter of BIM-GIS integration. Based on a requirements analysis and an evaluation of existing standardized information models, this paper presents CityGML EnvPlan ADE, a new 3D information model for integrating BIM and environmental planning. As a proof of concept, the information model is tested in a real railroad construction project.