An analytical mass transfer model for predicting emissions of Volatile Organic Compounds (VOCs) from multi-layered building materials and the instantaneous VOC material-phase distribution is developed. Different from the mass transfer models in the literature, it is able to describe the characteristics of VOC emissions from a wall with an arbitrary number of layers of different materials and with convective surfaces on both sides, and it does not neglect the mass transfer resistance through the gas-phase boundary layer. The model is validated with experimental data from the literature. The model provides a powerful tool for predicting VOC emissions from composite materials such as furniture and layered wall structures. Based upon the model and the dimensionless analysis, the applicable condition of Kumar and Little's double-layer model is discussed. (c) 2006 Elsevier Ltd. All rights reserved.