Unique requirements for Smoke Alarms in Class 1B Buildings

The Technical Team often receive enquiries regarding the rules and standards for smoke alarm installation.

While most members have a reasonable understanding of the requirements for domestic housing and rental properties, there is often confusion regarding Class 1B buildings. These are buildings that are being used for more transient purposes, such as boarding hourses and Air BnB and Stayz properties.


The requirement for smoke alarms in these premises is quite different.

In Class 1B buildings there must be interconnected smoke alarms installed in every bedroom, every corridor or hallway associated with a bedroom, or if there is no corridor of hallway, in an area between the bedrooms and the remainder of the building and each other storey.

There must be a system of lighting installed to assist evacuation or occupants in the event of a fire and it must be activated by the smoke alarms and consist of a light incorporated within the smoke alarm or the lighting located in the corridor, hallway or area served by the smoke alarms.

Please refer to the following diagram:

More information can be found in the section 9.5.3 of the NCC 2022.