The current practice for information sharing with building information modelling (BIM) is a distributed data sharing based on conversions. Conversions are problematic due to data loss, redundancy, and conflicting information. A single data schema used by all applications is a requisite for a conversion-free data collaboration. In the study, a software development kit (SDK) was developed, which implements required features and guarantees compatibility between BIM programs. Three independent applications 3DTrussme, Leonardo, and Viewer were developed using SDK. A cloud service for handling the shared model was implemented. In the experiments, Leonardo was used for modelling walls, 3DTrussme for truss design, and Viewer for model viewing. All three applications were using the same shared model on the cloud. In the experiments, the information exchange occurred without conversions and all data was saved only once on the cloud database. Without conversions and duplicates less conflicts and redundancies occurred, which lead to better data integrity and integration. Using SDK, there was no technical barrier for applications to join the single shared model ecosystem, but a drawback was that existing BIM programs are not compatible without remarkable changes. The performance was acceptable on the test run, but in real use, the size of the model and the number of applications and users, will be much larger. However, a conversion-free single shared model approach can be a possible trend to the development of the next generation BIM as well as a potential alternative for current data sharing methods using distributed files, conversions, and linked data.