A simplified indoor air quality (IAQ) model has been applied to predict IAQ in an Australian house, using environmental chamber measurements of source strengths, house ventilation and room size. Total volatile organic compounds (TVOCs) was used as the model pollutant in this study. The validity of the IAQ model was initially assessed by comparing model predictions with measurements in the house over a period of time. The root mean square error between the measured and predicted values was 0.039. This model explains 57% of the potential for error.