Stella has been successfully used to model water supply systems [1] including the representation of residential demand [2] in such systems (Stella is a product of ISEE Systems, Hanover, NH USA.) This paper documents the use of this modeling tool in simulating demand from several appliances common to commercial water users and applying this technique to commercial water auditing. The application of the model to the audits of six commercial organizations is presented. The model is being used for water management/conservation studies but also has potential for representing commercial water demand in more comprehensive supply system models.