Highly advanced computer models for the prediction of sound in rooms are now available. However, these tools are complex and require a skilled acoustician to use them effectively and hence there is a need for simpler models. A simple model needs to be accurate and quick to use, but most importantly should require a minimum amount of input data to construct the model. The resulting models are freely available to use and can be found at http://www.sbu.ac.uk/acogrp/steve.html.