The Hidden Cost of Apartment Ventilation
A bathroom exhaust outlet looks like a small detail on an apartment façade. But repeat it across multiple floors, alongside laundry outlets and nearby windows, and finding the right place for the air to go can become a much bigger design issue.
6 m
Grouping radius for nearby exhaust outlets under AS 1668.2:2024
1668.2
The current ventilation standard
2027
NSW adopts NCC 2025 on 1 May 2027
1Outlets are now assessed together
Under AS 1668.2:2024, nearby exhaust outlets within a 6 m radius are assessed together when determining their combined airflow. That airflow is then used to assess the required separation from openings and outdoor air intakes.
For apartments with exhaust grilles repeated across the façade or stacked between floors, checking each outlet on its own may no longer give the full picture
2Where floor space comes in
If the planned outlets cannot meet the separation requirements, they may need to be moved or the air routed elsewhere. That could mean extra ductwork or risers, adding cost and taking up space in the building.
3Timing matters
NSW is preparing to adopt NCC 2025 on 1 May 2027. For apartment projects still on the drawing board, checking the exhaust strategy early gives designers more room to resolve these issues before the façade and floor plans are locked in.
What this means in practical terms
Assess outlets together
Grilles repeated across the façade or stacked between floors are grouped within a 6 m radius when determining combined airflow.
Plan the exhaust route early
Where façade separation can’t be achieved, repositioning outlets or internal risers may be needed — affecting layouts and floor space.
Design while plans are flexible
With NCC 2025 arriving in NSW on 1 May 2027, early assessment helps avoid a difficult redesign later.
Designing apartments? Haron Robson now powered by BESTEC, can help identify ventilation constraints while there is still flexibility in the design.
