This project was a pilot of a larger upcoming project, where the aim is to produce a national interoperable data model for every valid zoning and city plan in Finland. The project is part of the development of the Finnish Environment Institute’s Built Environment Information System and the harmonization of national land use planning information. The aim of this presentation is to present the overall workflow of the project and the transition from proprietary data towards an open source national database with common spatial and descriptive information. Currently the data used in municipal decision making processes in Finland consists of proprietary data that is lacking spatial information or is outdated. The transformation of the zoning and city plans from two different data providers created a lot of topological errors and unmatched geometries. QGIS was a key tool for fixing these errors - the digitizing and geometry repair tools were used in solving these issues. This pilot project was implemented in Southern Savonia, Finland. In the region, zoning has been executed for approximately 80 % of the whole land area. The focus of the project was to investigate the compatibility of the base data and how to automate the processes of merging, fixing, updating and comparing the data. The data was in vector format and was provided by the National Land Survey of Finland and municipalities of Southern Savonia. The automation processes were built with a python script and the quality control was made with manual digitization. The official documentation of the zoning and city plans were included in the borderline vector data. The final product was uploaded to a GitHub repository. The project also managed to produce a timeline for the upcoming nationwide project and the distribution between automated and manual workload in similar projects.