The VIRTERF prototype combines recent developments in computer vision and reverse engineering with specific needs of professionals working in the field of architectural conservation. The development of the software is explained as based on requirements of possible end-users. Image based modelling techniques using automatic correspondence analysis, reverse engineering modelling and a layer-like annotation technique in a CAD environment are developed that tailor the needs of those professionals in terms of precision, of the nature of the documentation. The prototype programme has been tested on a number of case studies and those applications have revealed its strong and weak points.