This paper reports the results of a study to test two novel procedures to model dynamic thermal conditions of an enclosure within Computational Fluid Dynamics (CFD). The main area of investigation is the performance of the procedures in simulating the varying thermal response of the building fabric, the effects of external thermal load changes and the consequential effect on the air inside the enclosure. The dynamic thermal modelling procedures proposed utilise a transient time-varying grid schedule and Freeze-Flow techniques.