The flammability of interior finish materials for many applications is regulated using the ISO 9705 large-scale room corner fire test. To aid designers in developing new materials, a fire growth model has been developed to predict material performance in the ISO 9705 test using small-scale test data from ASTM E1354 cone calorimeter. The fire growth model includes a flame spread model linked with a two zone compartment fire model, CFAST Version 3.1.2. At a user selected time interval, the flame spread model uses the gas temperature from CFAST to predict the heat release rate of the fire at that time interval, and then provides CFAST with a new heat release rate to predict conditions during the next time step. The flame spread model is an improved version of the flat wall flame spread model previously developed for the U.S. Navy. The model is capable of predicting flame spread in a variety of configurations including a flat wall, a corner with a ceiling, flat wall with a ceiling, unconfined ceiling, and parallel walls. The fire growth model was used to predict the heat release rate and smoke production rate measured in eight ISO 9705 room corner fire tests on composite materials used in marine applications.