The solid-wall boundary effect on a building fire field model is discussed. In this model, the k - e model is used to predict the fire-induced flow (in primitive variables) and temperature field. The low Reynolds number model is proposed to substitute the traditional wall-function approach for describing solid-wall boundary effects. This is better because both the velocity and temperature distribution can be predicted within the buffer layer. Numerical experiments are performed on a physical model studying compartmental fire and an experiment on unconfined ceiling jet, both performed at the National Bureau of standards, U.S.A. For these simulations, better results arc achieved using this modified solid-wall boundary approach.