Multi-Dwelling Ventilation

Individual dwellings in a multi-dwelling development

For individual dwellings in a multi-dwelling development, BASIX recognises the following types of ventilation system:

• no mechanical ventilation – that is, natural ventilation
• individual fan, not ducted
• individual fan, ducted to façade or roof
• central ducted
• individual fan into central ducting plus Variable Speed Drive (VSD)
• motorised damper into central duct plus VSD.

Similar to single dwelling developments, BASIX recognises the following controls:

• interlocked to light – ventilation fan switch on/off is interlocked to the light switch
• continuous – ventilation fan operates continuously (24 hours per day)
• manual switch on/off
• manual on/timed off.

Common areas in multi-dwelling developments

For common areas in multi-dwelling developments, BASIX recognizes the following types of ventilation:

• no mechanical ventilation - that is, natural ventilation
• ventilation supply only (mechanical supply only)
• ventilation (supply and exhaust) (both mechanical supply and mechanical exhaust)
• air conditioning system
• mechanical ventilation with heat recovery (MVHR) system

Note that MVHR systems are not available as ventilation systems for carparks.

NCC requirements

All ventilation systems must be designed in accordance with the National Construction Code (NCC), which in turn requires compliance with Australian Standards 1668.1 and 1668.2 for mechanical ventilation systems.

BASIX calculations are based on AS1668.2 minimum airflow requirements and generally assume fan efficiency higher than the NCC minimum.