||This paper gives an overview and a description of different concepts for model checking. Model checking is defined as execution of predefined rules on a building information model, e.g. an IFC-file. Rules can be based on laws, regulations, codes, standards, advisory material or self defined requirements for generally or project specific use. The different concepts will be presented with a description and examples of use related to stages in the life cycle of the design process (ISO 22263:2008). The paper will discus mixed use of these concepts in basis of IDDS, integrated design and delivery (IDDS, 2010). Generally should model checking be use to support areas where the designer is not an expert – or other (repetitive) tasks human performance is error prone. An model who have passed all checks can at it’s best said to be “not bad”, and never to be the best designed building. Reasoned feedback is an important part of model checking.The following concepts will (so far) be presented: A) Validating model checking. The checking is performed against a set or rules, that all must be passed, or not activated, to pass the validation. Examples are checking against codes or standards. Following sub-types: Geometry based, information based and mixed systems will be explained. B) Asking model checking. This is rules applied on defined situations who ask for a choice between different alternatives. Examples are choose of venetian blinds and ventilation related to area of window. C) Self checking and adaptive model checkingExample of this is the adaptation of the diameter of the column in response to number of floors. D) Reversed model checkingExamples are checking a model and give feedback on which codes / standards, or parts of this that is relevant. Support for manual checkingReference:IDDS, 2010. Introduction to Integrated Design and Delivery Solutions, http://www.cibworld.nl/site/programme/priority_themes/integrated_design_solutions.html , (visited: 201-03-30).ISO 22263:2008. Organization of information about construction works -- Framework for management of project information. http://www.iso.org/iso/search.htm?qt=22263&sort=rel&type=simple&published=on (visited: 2010-03-30).