  The modular technology of development of the problem-oriented CAD expansions
is applied to a task of designing of profiles of outside networks of water
supply and water drain with realization in program system TechnoCAD GlassX. The
unity of structure of this profiles is revealed, the system model of the
drawings of profiles of networks is developed including the structured
parametric representation (properties of objects and their interdependence,
general settings and default settings) and operations with it, which
efficiently automate designing
