Airlocks for sanitary compartments - when are they required?

The question is often asked if it is required to install an airlock between a kitchen and a sanitary facility.

If a WC or a bathroom containing a toilet pan opens directly on to a kitchen, the issue can be contaminated air entering the kitchen. An airlock is designed to provide a buffer zone between the two rooms to prevent this occurring.

The Building Code of Australia (BCA) Volume 2 requires that a sanitary compartment or a room containing a toilet must not open directly into a kitchen or pantry unless an airlock is provided by a hallway or other room. This is required even if the sanitary compartment has an openable window, but there is another way to comply with this provision.

If the sanitary compartment is fitted with mechanical exhaust ventilation then the room can abut a kitchen or pantry, but the exhaust fan must be ventilated directly to the outside of the building by way of ducts, or into a roof space where the roof has adequate ventilation.

A roof that is considered to be adequately ventilated is a tiled roof without sarking that will provide air-flow between the tiles. If the roof has sarking or if it is a metal roof then ventilation would need to be provided via vented eaves or roof vents or a combination of both to comply.

The figure below from BCA Volume 2 shows a situation where a sanitary compartment can open directly onto a kitchen.

The above is intended to provide general information in summary form. The contents do not constitute specific advice and should not be relied upon as such. Formal specific advice should be sought by members with respect to particular matters before taking action.  ABN 99 004 631 752