The article presents how the Exodus method can be used to simulate heat transfer through opaque building components. The components are modelled as Linear Time Invariant systems described by their thermal impulse response functions. This method can be used to determine the temperature at any point inside the wall. Although the point can be selected arbitrarily, the research was focused on the inner surface of the wall. This temperature is particularly helpful in determining heat fluxes transferring external walls of the building in transient conditions. It can be also used to obtain the average radiation temperature in the heated rooms in order to estimate the variable thermal comfort conditions. The results of the Exodus method were verified by a comparison with the ones obtained from a more advanced simulation software Ansys CFX. The proposed method allowed for much faster calculations while preserving the results quality. (C) 2013 Elsevier B.V. All rights reserved.