Wind region
Wind region is the geographic wind hazard zone (A, B1, B2, C, D) under AS/NZS 1170.2 and AS 4055. Determines whether a site is non-cyclonic or cyclonic.
Ask Chalkline about this →A wind region is the geographic zone assigned to a location in Australia under AS/NZS 1170.2:2021 and AS 4055:2021, indicating the baseline wind hazard for that area. The wind region is the starting point for determining a site’s wind classification: it establishes whether the classification will be non-cyclonic (N class) or cyclonic (C class), and sets the regional wind speed multiplier used in the classification tables.
Under AS 4055:2021 and AS/NZS 1170.2:2021, Australia is divided into five wind regions:
- Region A: normal hazard. Most of southern and eastern Australia, including all capital cities except Darwin. Typical N1 to N4 classifications.
- Region B1: intermediate hazard. South-east Queensland including Brisbane and the Gold Coast corridor. Typical N3 to N5.
- Region B2: intermediate hazard, higher. Northern NSW coast above Coffs Harbour, parts of the central QLD coast. Typical N3 to N5.
- Region C: cyclonic. Northern QLD coast, Darwin and the NT coast, WA north of Carnarvon. Typical C1 to C3.
- Region D: severe cyclonic. Pilbara coast of Western Australia. Typical C2 to C4.
Also known as: wind hazard region.
Category: Compliance & approvals.
Why it matters for builders: the wind region is the primary determinant of whether a build will have a cyclonic or non-cyclonic wind class and the cost level of the structural specification. Builders pricing work in Region C or D should factor in the significantly higher structural requirements for tie-downs, fixings, and cyclone-rated products before locking in a price.
Related
- AS 4055 wind loads for housing, the standard that maps wind regions and site factors into wind classifications for housing
See also
Last updated: 2026-05-08. Verified: 2026-05-08. Quarterly review for currency.