In our previous research, we worked on on-line form recognition by exploiting semantic constraints between fields using Bayesian networks. The semantic constraints allowed us to check the co-existence of fields filled up by hand by users. In this paper, we propose to test the use of architectural constraints for a design problem related to the modelling of shower areas. The proposed method exploits the physical dependencies between different parts of a space shower. The tests are performed on a database composed of 500 forms representing 5 models. The first results reach a recognition rate of 96.7%.