Digital building diagnostics – a digital transformation project. Due to traditional analogue working methods and heterogeneous forms of documentation, the potential of building diagnostics for assessing existing buildings has not yet been fully exploited. As part of the two-year research project Digital Building Diagnostics, digital methods and tools were developed to improve the process steps of data collection, data evaluation and data linking with Building Information Models (BIM). This resulted in a capture tool for digital data capture and structured data storage, an evaluation tool for partially automated data preparation and evaluation, and a visualization tool for displaying investigation results in BIM. On one hand, the tools developed improve working methods by relieving specialist engineers of repetitive, time-consuming work steps. On the other hand, they reduce the susceptibility to errors and increase the quality of the structural diagnostic examination results. Overall, the project results contribute to connecting building diagnostics to the omnipresent digitalization in the construction industry.