The Building Code of Australia in Part E2 Smoke Hazard Management in clause E2.2 General requirements stipulates compliance with Table E2.2a General Provisions which requires any fire-isolated stairway to be provided with stairwell pressurisation – an automatic air pressurisation system. The BCA requires a stairwell pressurisation system to ensure the occupants of a building in a fire emergency have sufficient time to evacuate the building before the stairwell becomes untenable. A stairwell pressurisation system will be nominated by the building surveyor/ building certifier in the essential safety measures determination/ schedule.
Building Code of Australia
A stairwell pressurisation system must be installed in accordance with AS/NZS 1668.1:1998 The use of ventilation and air-conditioning in buildings – Fire and smoke control in multi-compartment buildings and the building permit. When installed, the stairwell pressurisation system will be in Normal Mode and Fire Mode (if needed). In the event of a fire detection system detecting a fire in the buildings, the stairwell pressurisation system will automatically change to fire mode and start the system.
The following illustration depicts stairwell pressurisation relief in Class 2 or 3 buildings.