Land around Cairns Airport is covered by Australian Noise Exposure Forecast contours, and development inside them generally needs an aircraft noise assessment to AS 2021 as part of the development application. In a tropical climate the real design problem is the tension between the sealed, heavier construction that keeps aircraft noise out and the ventilation that keeps a building comfortable. We work through that trade-off with the design team.
When the site falls inside the ANEF contours and the planning scheme's airport environs provisions call for an assessment. Under AS 2021, houses, home units and flats are acceptable below ANEF 20, conditionally acceptable between ANEF 20 and 25, and unacceptable above ANEF 25. Other building types have their own thresholds.
Conditionally acceptable development has to show that the construction will achieve the indoor design sound levels in AS 2021.
AS 2021 Acoustics — Aircraft noise intrusion — Building siting and construction sets indoor design sound levels by building type and room — lower for sleeping areas than for living areas — and gives the method for working out how much noise reduction the building envelope must provide against the aircraft expected at the site.
A report setting out the site's ANEF zone, the design aircraft noise levels, the noise reduction each room type needs, and the roof and ceiling, wall, glazing and door constructions that achieve it, together with a ventilation approach that works with the windows closed. It is written to be lodged with the development application.
Most of the work is a desktop assessment from the drawings and the current endorsed ANEF, so it can usually be turned around within the design programme rather than holding it up.
A fixed fee based on the size of the building and the number of distinct room types.
Not while achieving the required noise reduction — AS 2021 assumes closed windows. That is why the ventilation strategy is part of the assessment: the building has to stay comfortable with them shut.
No. The ANEF describes cumulative exposure over a year. AS 2021 designs the construction against the noise of individual aircraft types expected at the site, which is what wakes people up.
The current endorsed ANEF for the airport, as reflected in the planning scheme. Airports revise their ANEF with their master plans, so it is worth confirming the version before design starts.