The goal of Building Information Modeling (BIM) is the integral and comprehensive digital modeling of all properties regarding a building, its planning and construction process as well as maintenance and use. This is combined with the overarching objective within BIM to integrate and support all involved experts aiming towards an improved collaboration. Currently the necessary data often only exists in a very fragmented and uncoordinated way throughout different subsections, as well as planning and construction phases. A lack of organized information management is especially noticeable in finalized built objectives during questions of conversion and refurbishment. BIM tries to mediate between the different views of its users and allows for a coordinated accumulation of data, as well as synchronously keeping the planning status up to date. However, in most cases essential information is missing or not used throughout the complete lifecycle of the building. Consequently, there are clear gaps between the different phases of planning, construction and maintenance. Within this paper, we give an evaluation of applicable methods for data collection and modeling of the actual inventory of components with regard to position, geometry and semantics (e.g. material) for the purpose of a comprehensive and BIM-compliant as-built documentation. This allows the analysis of missing interfaces and data. Considered from a process automation viewpoint, we identify missing BIM data e.g. for assembly processes within construction in order to create a BIM-aided planning process that continues into actual fabrication and construction. Based on this, we discuss possibilities for the implementation of user requirements in order to develop a comprehensive semi-automated decision support tool for BIM users. Primary goal is to provide concepts for the integration of construction processes as well as options for conversion planning and construction of buildings. These targets imply a continuous updating of the BIM models (including the semantic parameters) from a continuous 'as-built' acquisition and modeling of the construction progress. While BIM primarily is being discussed as a cooperative working methodology in the new planning of buildings, we also consider the required information for future conversion and refurbishment of the building and the required level of development, in order to complete the lifecycle approach of BIM.