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AS 2021: aircraft noise intrusion, building siting and construction

AS 2021-2015 sets indoor noise targets and the glazing, wall and ceiling treatment for homes in 20 to 25 ANEF aircraft-noise zones; above 25 ANEF is unacceptable.

By Chalkline. Last updated 1 June 2026. Verified 1 June 2026.

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AS 2021-2015, Acoustics, Aircraft noise intrusion, Building siting and construction is the national standard that sets how close to an airport you can build a noise-sensitive use and how the building must be constructed to keep aircraft noise out. It is the standard a planning scheme calls up once a lot sits inside an ANEF contour.

Where it sits

AS 2021 is triggered by the airport noise overlay on a planning certificate or scheme map. The overlay carries an ANEF index value (20, 25, 30). The standard turns that value into a land-use decision and, where building is allowed, a construction specification. It works alongside the planning scheme, not instead of it: the scheme says whether you can build, AS 2021 says how.

What it requires

The standard has two halves.

  • Site acceptability by ANEF zone. Below 20 ANEF residential is acceptable with no special treatment. Between 20 and 25 ANEF it is conditionally acceptable, meaning permitted only if the building meets the standard’s acoustic construction requirements. Above 25 ANEF new residential is unacceptable, and most consent authorities refuse it. Less sensitive uses get more headroom: hotels, for example, stay conditionally acceptable up to about 30 ANEF.
  • Indoor design sound levels. For a conditionally acceptable site the building must hold habitable rooms to the standard’s indoor targets with windows shut, typically around 50 dB(A) in sleeping areas and 60 dB(A) in other habitable rooms. That drives the glazing, wall, roof and ceiling build-up, and the sealing of gaps.

What a builder does with it

Get an acoustic consultant’s report before the window schedule is locked, not after. The report sizes the glazing (often acoustic laminated units, not ordinary laminated safety glass), the wall and ceiling construction, and the door and seal details needed to hit the indoor target. Because the targets assume windows closed, a compliant house almost always needs mechanical ventilation so occupants are not forced to open windows for air. Treat all of this as a cost line at feasibility: it is real money and it is easy to miss on an otherwise routine Class 1a.

References

See also

Last updated: 2026-06-01. Verified: 2026-06-01. Quarterly review for currency.

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