Behind the NCC sits a library of Australian Standards that the Code calls up as Deemed-to-Satisfy — the ones that actually tell you how to frame, pour, waterproof and fix. This is the working register of the core residential standards, by topic. (Standards are copyright — referenced by number here, not reproduced; always work to the current edition.)
Timber framing and treatment
- AS 1684 Residential timber-framed construction (a four-part series; Part 2 non-cyclonic N1-N4, Part 3 cyclonic) is the NCC DtS for Class 1 and 10 timber framing — member sizing, span tables (rafters, joists, lintels by species, stress grade, wind class and roof pitch), bracing and tie-down load paths, and fixing. Reference the span tables for the member and wind class rather than guessing.
- AS 1604 series — timber treatment hazard classes: H2 for internal, above-ground framing protected from weather (internal framing in termite areas); H3 for above-ground framing exposed to weather (external wall framing under cladding, battens, veranda framing). Match the treatment class to the exposure — and the fixings to both.
Steel, concrete and masonry
- Steel framing: AS 3623 (domestic metal framing, up to 2 storeys), AS/NZS 4600 (cold-formed/light-gauge steel design), and the NASH Standard for residential and low-rise steel framing (an NCC-recognised acceptable construction standard for design, bracing and tie-down).
- Concrete: AS 3600 (concrete structures — strength, durability, cover, detailing) with AS 2870 the residential slabs-and-footings companion (see Reactive Soils & Footings).
- Masonry: AS 3700 (masonry structures — design, durability, control joints, reinforcement and tolerances for brick and block).
Waterproofing — the defect hot-spot
Waterproofing causes more defect claims than almost anything, so know these:
- AS 3740:2021 Waterproofing of domestic wet areas — internal wet areas (bathrooms, showers, laundries). Shower floors are fully waterproofed; shower walls to at least 1,800mm above the floor within the shower; all junctions (wall/floor, internal angles with bond-breakers) and penetrations (wastes, mixers) detailed watertight.
- AS/NZS 4858 — the wet-area membrane performance standard the membranes themselves comply with.
- AS 4654.1 and .2 — external above-ground waterproofing (balconies, terraces, roofs, planter boxes): UV-stable membranes, falls to drainage, edge terminations and (usually) flood testing before tiling.
- Certification: there is no single national certificate — the surveyor must be satisfied with the evidence: a statement from the licensed or accredited installer or manufacturer (installed to AS 3740 + AS/NZS 4858), product compliance certificates, and flood-test results.
Fixings, tie-down and corrosion
- AS 3566 sets fastener corrosion classes — Class 3 or higher externally, and stainless steel or hot-dip galvanised in coastal or severe environments (never mild steel).
- Tie-down runs the continuous load path per the AS 1684 schedule (or NASH for steel): truss/rafter to top plate (straps and hurricane ties), plate to stud to bottom plate, and bottom plate to footing hold-downs sized for uplift and lateral loads — critical in higher wind classes (see Bushfire BAL & Assessment for the cyclonic detail).
Roofing and wind
- AS 1562.1 — metal sheet roof and wall cladding (Colorbond/Zincalume — materials, design, installation).
- AS 2050 — installation of concrete and terracotta roof tiles.
- AS 4055 (housing wind classes N1-N6, C1-C4) and the broader AS/NZS 1170 series (structural design actions) set the wind loads the roof, frame and tie-down are designed to.
Quick-reference register
| Topic | Primary standard(s) |
|---|---|
| Timber framing | AS 1684 (Parts 1-4) |
| Timber treatment | AS 1604 series (H2/H3) |
| Steel framing | AS 3623, AS/NZS 4600, NASH |
| Concrete | AS 3600, AS 2870 |
| Masonry | AS 3700 |
| Internal wet-area waterproofing | AS 3740, AS/NZS 4858 |
| External waterproofing | AS 4654.1 & .2 |
| Roofing — metal / tiles | AS 1562.1 / AS 2050 |
| Wind loads | AS 4055, AS/NZS 1170 |
| Fixings & corrosion | AS 3566 |
Common mistakes
- Using the wrong timber treatment class for the exposure (H2 where H3 is needed).
- Waterproofing shower walls below the 1,800mm height, or skipping the flood test.
- Mild-steel fixings in a coastal environment (corrosion and failure).
- Treating an old edition as current — always check the edition the NCC calls up.
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