This paper describes the prototype of a concept modelling software. It is used to figure out a good layout of chemical plants and estimates the amount of piping material (material take off, MTO) to be used. The conceived layout is a result of the extended basic engineering and is used as a basis for further detail engineering. The described software creates extended equipment models including equipment related piping and areas for maintenance. It creates simple steel structures with a mouse click or helps to customise more complicated ones. Next, layout modelling by rule based algorithms and force directed placement is employed to receive optimal equipment positions. A routing algorithm connects the equipment according to the "from-to-list" and a MTO can be generated. Finally, some evaluation criteria analyse the results and may show flaws in the layout that shall be solved by the engineer. Since only a minimum effort has to be invested, the software is also suitable to estimate a bid price for an advertised project. (C) 2003 Elsevier Ltd. All rights reserved.