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Curtain wall

A curtain wall is a non-loadbearing glazed facade hung off slab edges on commercial buildings. Covers stick vs unitised, AS 1288, and NCC non-combustibility.

By Chalkline. Last updated 11 June 2026. Verified 11 June 2026.

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A curtain wall is a non-loadbearing facade hung off the structural slab edges or columns of a building. It carries no floor or roof load; its job is to keep weather out, resist wind, and transfer those loads back to the structure at each floor. On commercial buildings (Class 5 to 9) it almost always means a glazed aluminium framing system.

Stick vs unitised

Stick-built systems are assembled on site rail by rail: mullions and transoms fixed to the slab edge, then glass or spandrel panels glazed in. Suits complex geometry or small areas.

Unitised systems arrive as factory-assembled storey-height panels, craned into place and interlocked. Faster programme and tighter QC; the standard choice above three or four storeys.

What it must do

  • Weatherproofing: air and water resistance tested to AS/NZS 4284:2008 (verified 2026-06-11, Standards Australia)
  • Wind transfer: loads transfer to slab edge at each anchor; facade engineer specifies capacity and slab-edge tolerance
  • Glazing: glass panels sized under AS 1288:2021 (verified 2026-06-11)
  • Thermal: SHGC and U-value of the assembly feed Section J energy compliance

Non-combustibility

NCC 2022 Volume One C2D10 requires that external walls of Type A and Type B buildings, including facade covering, framing, and insulation, be non-combustible (verified 2026-06-11, ABCB). Gaskets, sealants, and thermal break materials are permitted concessions under C2D10(4). This came into sharp focus after the Lacrosse fire (Melbourne, 2014) and the broader ACP cladding-crisis investigations.

For the builder

Slab-edge tolerances drive everything: anchor locations and bracket-adjustment range must be confirmed from structural drawings before the facade contractor arrives. A facade engineer and specialist glazing contractor are required; curtain wall falls outside residential glazier scope.

Also known as: curtain wall facade, glazed curtain wall.

See also

Last updated: 2026-06-11. Verified: 2026-06-11. Quarterly review for NCC Volume One C2D10 and AS/NZS 4284 currency.

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