NCC 2022 Volume One - Building Code of Australia Class 2 to 9 buildings
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B1
Part B1 Structural provisionsPart B1 Structural provisions
The magnitude of individual actions must be determined in accordance with the following:
Importance level | Building Types |
---|---|
1 | Buildings or structures presenting a low degree of hazard to life and other property in the case of failure. |
2 | Buildings or structures not included in Importance Level 1, 3 and 4. |
3 | Buildings or structures that are designed to contain a large number of people. |
4 | Buildings or structures that are essential to post-disaster recovery or associated with hazardous facilities. |
Importance Level | Annual probability of exceedance for non-cyclonic wind | Annual probability of exceedance for cyclonic wind other than Wind Region D north of the Tropic of Capricorn | Annual probability of exceedance for cyclonic wind in Wind Region D north of the Tropic of Capricorn | Annual probability of exceedance for snow | Annual probability of exceedance for earthquake |
---|---|---|---|---|---|
1 | 1:100 | 1:200 | 1:250 | 1:100 | 1:250 |
2 | 1:500 | 1:500 | 1:1000 | 1:150 | 1:500 |
3 | 1:1000 | 1:1000 | 1:2000 | 1:200 | 1:1000 |
4 | 1:2000 | 1:2000 | 1:5000 | 1:250 | 1:1500 |
B1D3(a)(iv) does not take effect until 1 October 2023.
B1D3(a)(iv) does not apply to a Class 7b building—
In Western Australia state variations apply to wind regions B and D, this includes wind region B2 as referenced in AS/NZS 1170.2.
The state variation for wind region B or B2 will ensure that designers consider the combination of peak external pressures and increased internal pressures in design of buildings and use a cyclonic (C) classification instead of non-cyclonic (N) classification. The definition of design wind speed is varied in WA Schedule 1 to identify that wind region B is a C classification in Western Australia. Other changes have also been made to reflect this.
In addition to a variation to clauses B1D3 and B1D4, a variation is made to the application of AS/NZS 1170.2 when used as either a primary referenced document or a secondary or subsequent referenced document. Refer to WA Schedule 2 and WA Part B2.
The state variation for wind region D applies only to those parts of region D located north of the Tropic of Capricorn. The 2021 edition of AS/NZS 1170.2 includes a reduction in design wind speeds for wind region D. The variation will retain similar design wind speeds for wind region D as the 2011 edition of AS/NZS 1170.2 previously referenced in the National Construction Code.
Importance Level | Annual probability of exceedance for non-cyclonic wind | Annual probability of exceedance for cyclonic wind other than Wind Region D north of the Tropic of Capricorn | Annual probability of exceedance for cyclonic wind in Wind Region D north of the Tropic of Capricorn | Annual probability of exceedance for snow | Annual probability of exceedance for earthquake |
---|---|---|---|---|---|
1 | 1:100 | 1:200 | 1:250 | 1:100 | 1:250 |
2 | 1:500 | 1:500 | 1:1000 | 1:150 | 1:500 |
3 | 1:1000 | 1:1000 | 1:2000 | 1:200 | 1:1000 |
4 | 1:2000 | 1:2000 | 1:5000 | 1:250 | 1:1500 |
The structural resistance of materials and forms of construction must be determined in accordance with the following, as appropriate:
Application | Lift shaft vision panels more than 65 000 mm2, door panels, and lift shafts | Lift shaft vision panels less than or equal to 65 000 mm2 |
---|---|---|
Laminated glass | 10 mm (0.76 mm interlayer) | 6 mm (0.76 mm interlayer) |
Toughened/ laminated glass | 10 mm (0.76 mm interlayer) | 6 mm (0.76 mm interlayer) |
Annealed glass with security polyester film coating | 10 mm | 6 mm |
Safety wire glass | Not applicable | Subject to fire test |
Polycarbonate sheet | 13 mm | 6 mm |