Despite advances in the understanding of fire over the past decades [Quintiere 2001] and despite the advances in computing capacity, our ability to predict the behaviour of fires in general and building fires in particular remains very limited. Fire continues to cause much damage to material property and many deaths and injuries – for example for in the UK in 2002 roughly 100,000 building fires were recorded, causing about 500 deaths and 13,000 non-fatal injuries [Office of the Deputy Prime Minister 2005], and creating material losses of about 1,500 Mio Pounds (2,200 Mio Euro), which is equivalent to 0.14 % of the gross domestic product [Wilmot 2005]. It is not just the biggest fires which need to be addressed if the number of casualties is to be greatly reduced: despite the number of fires over the past years in public buildings causing multiple deaths, the majority of fire deaths occur from incidents in residential properties each involving small numbers of casualties [Gebäudeversicherung des Kantons Bern 1992], [Office of the Deputy Prime Minister 2005]. If active and passive protection measures, and operational procedures and training for firefighters are to be improved, then the available knowledge on the behaviour of fires needs to be increased.