The module provides the possibility of designing internal gravity sanitary sewage systems. It includes graphic editing, selection of pipelines (pipe diameters, fittings), 2D and 3D drawing presentation, bill of materials. It takes into account sanitary appliances placed in rooms, which results in a complete model of the installation including sanitary equipment in rooms. In the course of project creation, a 3D model of the project is created, the preview of which can be used to control compliance with the expected state on an ongoing basis.  The model takes into account the designed gradients of pipe-runs. Visualisation of the model can take into account installations designed (or in progress of designing) in other modules of InstalSystem 5 package, in particular the ‘Tap water systems’ module.