The June 2001 revision of the New Zealand Building Code ‘Approved Document C/AS1’ for fire safety (BIA 2001) introduced a new type of fire safety precaution (FSP). Termed a Type 5 alarm, this is applicable within accommodation and multi-unit residential buildings. Essentially, the Type 5 alarm allows localised warning and non-brigade connected alarms in guest suites. This is a departure from previous practice and increases the fire risk to occupants. The benefits are the reduction in unnecessary Fire Service call-out and the reduction in unnecessary total building evacuation. Qualitative arguments supported the new Type 5 alarm. This research develops a quantitative methodology to measure the increased risk. It concludes, that given the ability to measure the risk, decisions such as the introduction of the Type 5 alarm, which lower safety, should be supported by a formal and quantitative risk analysis.