Published validation tests developed within majorresearch projects have been an invaluable aid to programdevelopers to check on their programs. This paper sets out howselected ASHRAE Standard 140-2004 and European CENstandards validation tests have been incorporated into theESP-r simulation program so that they can be easily run byusers and also discusses some of the issues associated withcompliance checking. Embedding the tests within a simulationprogram allows program developers to check routinelywhether updates to the simulation program have led to significantchanges in predictions and to run sensitivity tests to checkon the impact of alternative algorithms. Importantly, it alsoallows other users to undertake the tests to check that theirinstallation is correct and to give them, and their clients, confidencein results. This paper also argues that validation testsshould characterize some of the significant heat transferprocesses (particularly internal surface convection) in greaterdetail in order to reduce the acceptance bands for programpredictions. This approach is preferred to one in which validationtests are overly prescriptive (e.g., specifying fixed internalconvection coefficients), as these do not reflect howprograms are used in practice.