Traditionally the New Zealand Fire Service has been giving the advice to the New Zealand public that it is safer to sleep with their bedroom doors closed. The advice given is not backed up by any technical evidence that it is the best way to position your bedroom door when asleep. Sleeping with your bedroom door closed reduces smoke migration into the bedroom. With the increased use of simple, cheap smoke alarms in many residential houses, it is important to investigate if this is the safest way to position your door when asleep. The aim of this research is to determine whether it is safer to sleep with bedroom doors open or closed in the event of a fire by performing a probabilistic risk assessment. The recommendation made by this research can be used by Fire Services to give the best advice on whether it is safer to sleep with bedroom doors open or closed. The analysis is carried out using two methods. Firstly by evaluating the expected risk to life to occupants by using FiRECAM (Fire Risk Evaluation and Cost Assessment Model), which is being developed at the National Research Council of Canada. The second method used determines the probability of failure using an event tree method. Both analyses recommend that it is safer to sleep with bedroom doors closed while sleeping. Although they agree with each other there are many issues requiring further investigation in both analyses. The results of the analyses are only comparable in a relative sense and are not yet able to be compared in absolute terms.