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Queensland Cyclone Tie-Downs: Which Wind Regions Count

Which Queensland wind regions the NCC treats as cyclone areas, which timber framing standard each one uses, and why tie-downs must run in one chain from roof to footings.

Clause NCC22 H1D6 Clause NCC22 QLD H1D6 Clause NCC22 Sch1 Table 4 Clause QLD Building Act 1975 Clause QLD HRP Eligibility Clause ABCB NCC25 Adoption

The requirement

The NCC treats only Region C and Region D as cyclone areas. In Queensland that is the coastal band running from Cape York south to about Bundaberg. Homes there frame to AS 1684.3. The rest of the state uses AS 1684.2 or AS 1684.4. Read your block off the wind map.

Which edition you are working to. Queensland still builds to NCC 2022. NCC 2025 came out on 1 May 2026. But Queensland does not pick it up until 1 May 2027. So the clause numbers below are NCC 2022 numbers. The code bites here through the Building Act 1975, which names it in section 12.

How the regions split. The NCC lists the wind classes in Schedule 1, Table 4. Region A and Region B get the N classes, N1 up to N6. Region C and Region D get the C classes, C1 up to C4. The C stands for cyclone winds. So a site is a cyclone job only if it lands in Region C or Region D.

You may hear that Region B counts as a cyclone area. That is a Western Australia change to the code. Queensland has no such change. Here, all of Region B stays on the N side.

Where the band sits. On the NCC wind map the Region C band runs down the coast from Cape York to about 25 degrees south, near Bundaberg. It also wraps the Gulf of Carpentaria west to the Territory border. Cairns, Townsville and Rockhampton sit inside it. Brisbane and Toowoomba sit in Region B.

Mackay is not named on that map. It sits on the coast inside the band, so we read it as Region C. Treat that as our reading, not a printed fact. Check the map or ask an engineer for the site.

Do not step it out from the beach. The map lines are smoothed curves set in from a smoothed coastline. They are not measured off the real shore. The state does use a 50 km line, but only to hand out grant money under the Household Resilience Program. That is a funding rule, not a way to class a site.

Working out the wind. The Housing Provisions ask you to work wind actions to AS/NZS 1170.2 or AS 4055. That is clause 2.2.3(c). AS 4055 is the short path. But the house must fit the size limits in AS 4055 clause 1.2. That gate sits in Volume Two, at H1D6(6)(f) and H1D8(1)(b)(ii). The NCC prints the limits free in the notes under H1D8.

  • Eaves no higher than 6.0 m above the ground next to them.
  • Roof top no higher than 8.5 m, chimneys aside.
  • Width no more than 16.0 m, verandas in, eaves out.
  • Length no more than five times the width.
  • Roof pitch no steeper than 35 degrees.

A house outside those limits needs AS/NZS 1170.2 and an engineer.

One thing does not change at the region line. A house is Importance Level 2 either side of it. That means a 1 in 500 design event for both. What changes is the wind speed and the C class work that goes with it.

Framing. Clause H1D6(4) splits timber framing two ways. Cyclone areas take AS 1684.3. Other areas take AS 1684.2 or AS 1684.4. Queensland deletes that clause and puts in QLD H1D6(4). The split stays the same. But the state adds one rule. Your structural timber must be a species listed for that use in Book 2 of Construction timbers in Queensland.

The tie-down chain

The code’s own notes on cyclone areas spell out the job. The building has to pass wind forces down to the ground. It must not lift, and it must not slide off its footings. Three things do that work.

  • An anchorage chain, tying the roof through the walls to the footings.
  • Bracing, to stop the frame folding over sideways.
  • Continuity, so each part locks into the part next to it.

The notes put it plainly. Every connector has to carry the uplift, because the building is only as strong as its weakest link. The notes stop there. What follows is our own picture of that chain on a real job.

  • Sheets tied to the battens.
  • Battens tied to the rafters or trusses.
  • Trusses tied to the top plate.
  • Walls tied down to the floor frame.
  • Floor frame tied to the footings or the slab.

We print no strap, bolt or nail counts here. Those sit in AS 1684.3, which you have to buy. AS 1684.3 also has a stated limit on which wind classes it covers. We could not confirm that limit. Read it in AS 1684.3:2021 direct, or get an engineer on it.

Never copy a tie-down detail off a Brisbane job. It was built for an N class site.

Sources

  • ABCB Housing Provisions Standard 2022 (1 May 2023), clause 2.2.3 and Figure 2.2.3 — clause 2.2.3(c)(ii) requires wind actions for Class 1 housing to be determined in accordance with AS/NZS 1170.2 or AS 4055, except where varied by WA Part 2.3. Clause 2.2.3 carries no AS 4055 geometric limit; that limit is imposed in Volume Two (see the H1D6 source below). The note to Figure 2.2.3 states that coastal region boundaries are smooth lines set in from a smoothed coastline by 50, 100, 150 and 200 km, and that islands within 50 km of the coast take the same region as the adjacent coast. The map shows the Region C band running down the Queensland coast from Cape York to roughly latitude 25°S near Bundaberg, and around the Gulf of Carpentaria to the Northern Territory border, with Cairns, Townsville and Rockhampton inside it and Brisbane and Toowoomba in Region B. See ncc.abcb.gov.au.
  • ABCB Housing Provisions Standard 2022, Explanatory Information to clause 2.2.3, “Construction in cyclonic areas” — describes the intent as transferring wind forces to the ground so the building neither collapses, lifts, nor slides off its footings, by way of an anchorage system connecting roof to footings, a bracing system, and continuity between interlocked structural elements; and notes under “Anchorage” that each connector must carry the uplift force because resistance is governed by the weakest link. This is guidance, not a requirement. See ncc.abcb.gov.au.
  • NCC 2022 Schedule 1 Definitions, Table 4 “Wind classes” — pairs Regions A and B with the non-cyclonic classes N1–N6 and Regions C and D with the cyclonic classes C1–C4, with “N” denoting non-cyclonic and “C” cyclonic winds. Only Western Australia varies this to treat Region B as cyclonic; Queensland makes no equivalent variation. Clause 2.2.3 and Table 2.2.3b place Class 1 buildings at Importance Level 2, where the annual probability of exceedance is 1:500 for both cyclonic and non-cyclonic wind. See ncc.abcb.gov.au.
  • NCC 2022 Volume Two (1 May 2023), clause H1D6(4) and the Queensland variation QLD H1D6(4) — satisfies Performance Requirement H1P1 through AS 1684.2 or AS 1684.4 in non-cyclonic areas and AS 1684.3 in cyclonic areas. Queensland deletes H1D6(4) and substitutes QLD H1D6(4), keeping the same split and adding a requirement that structural timber be a species scheduled for the appropriate use in Schedules A, B or C of Book 2 of the December 2017 version of “Construction timbers in Queensland” (Qld Department of Agriculture, Fisheries and Forestry, as the instrument itself names it in QLD H1D6(4)(g)). The same Part limits AS 4055 to “buildings within geometric limits set out in clause 1.2 of AS 4055” at H1D6(6)(f) and H1D8(1)(b)(ii); the Explanatory information under H1D8 reproduces those limits free of charge as eaves underside not exceeding 6.0 m above adjacent ground, highest point of the roof (excluding chimneys) not exceeding 8.5 m, building width including verandas but excluding eaves not exceeding 16.0 m, length not exceeding five times width, and roof pitch not exceeding 35 degrees. See ncc.abcb.gov.au.
  • Building Act 1975 (Qld), s 12 (reprint current as at 1 February 2026) — defines the Building Code of Australia as the National Construction Code, volumes 1 and 2 including the Queensland Appendixes, published by the Australian Building Codes Board. This is the mechanism by which the NCC binds building work in Queensland. See legislation.qld.gov.au.
  • ABCB, NCC 2025 state and territory adoption information — NCC 2025 was released nationally on 1 May 2026, but Queensland’s adoption date is 1 May 2027, a 12-month deferral. NCC 2022 with the ABCB Housing Provisions Standard 2022 therefore remains the operative edition in Queensland. See ncc.abcb.gov.au.
  • Queensland Government, Household Resilience Program — eligibility for funding — describes the program area as up to 50 km from the coast, north from Bundaberg to Cape York and west to the Queensland/Northern Territory border, being part of “Cyclone Region C”. Bundaberg Regional Council localities are inside; the Fraser Coast Regional Council area is outside. This is grant eligibility guidance, not a site classification method. See qld.gov.au.
  • NCC 2022 Schedule of referenced documents — lists AS 4055:2021, AS/NZS 1170.2:2021, AS 1684.2:2021, AS 1684.3:2021 and AS 1684.4:2010 (incorporating Amendment 1), with no amendment annotation against the 2021 editions. See ncc.abcb.gov.au.
  • Not verified here: the wind classes AS 1684.3:2021 actually covers (its clause 1.4.2 scope limit is paywalled at Standards Australia); any tie-down, strap, bolt, connector, nail or spacing figure from AS 1684.2 or AS 1684.3; how C1–C4 is selected for a site; whether any 2024 amendments to the 2021 standards are picked up by the edition in force here; and whether NCC 2025 keeps the same framing split. Confirm each in the purchased standard, on ncc.abcb.gov.au, or with an engineer. Mackay’s region is our reading of the map, not a labelled point on it.

Related building rules

Content adapted from the National Construction Code 2022, provided by the Australian Building Codes Board under the CC BY 4.0 licence.

Frequently asked questions

Is Cairns in a cyclone wind region?
Yes. Cairns sits inside wind Region C on the NCC wind map. Townsville and Rockhampton do too. Region C is one of the two regions the NCC treats as a cyclone area. Homes there frame to AS 1684.3. Always read the map for the exact block.
Is Brisbane a cyclone area under the NCC?
No. Brisbane sits in wind Region B, and so does Toowoomba. The NCC treats Region B as a non-cyclone area everywhere except Western Australia. So a Brisbane house takes an N wind class and frames to AS 1684.2 or AS 1684.4.
Do I use AS 1684.2 or AS 1684.3 in Queensland?
It depends on the wind region. In a cyclone area you frame to AS 1684.3. Everywhere else you use AS 1684.2, or AS 1684.4 for the simple version. The split sits in clause H1D6(4), which Queensland rewrites as QLD H1D6(4) with the same two branches.
What building code edition applies in Queensland right now?
NCC 2022. Queensland has set 1 May 2027 as its start date for NCC 2025, a year after the national release. So every clause number you quote today is an NCC 2022 number. The Building Act 1975 is what makes the code bite in this state.
How far inland does the cyclone region go in Queensland?
There is no set distance you can measure on site. The NCC draws the region lines as smoothed curves set in from a smoothed coastline. So read your block off the wind map at Figure 2.2.3, or ask an engineer. Do not step it out from the beach.