In the present research project, a practical process for the digitisation of existing structures is to be developed into a BIM model that provides the prerequisite for upgrading or conversion measures. The results will be made available on the basis of existing digital tools in a form compatible with “open BIM”. This will give SMEs from the construction industry easier access to the complex topic of digitisation of existing buildings. It is essential that the digital BIM model can be the basis for the applications of training measures as well as conversions or for recalculations. The results will be supported through relevant bodies, associations and publications on SMEs.