Two suppliers can both write "AS 2047 compliant" on a quote. One has a NATA-accredited test report behind the words; the other has a sentence. AS 2047 is the Australian Standard for windows and external glazed doors in buildings, and a rating under it is earned by physically testing a representative specimen — not by description.
This article is the field guide to what that testing actually measures, so you can read a test report and know which numbers decide whether the window will survive your site's wind and rain.
What AS 2047 is — and what it is not
AS 2047:2014 sets out the requirements, materials, construction, installation and glazing for external windows, sliding and swinging glazed doors (including French and bi-fold doors), adjustable louvres, shopfronts, and window walls with one-piece framing.
It is a product standard for housing — "housing" meaning Class 1 buildings under the National Construction Code (NCC) — and its scope is bounded by AS 4055 (the wind-load standard it works alongside).
Two things it is not:
- It is not an energy rating. Thermal performance (U-value, solar heat gain) is covered separately by the WERS scheme run by the Australian Glass & Window Association (AGWA). A window can pass AS 2047 structurally and still be thermally poor.
- It is not an installation guarantee. The rating describes the standalone window or door unit, tested in a chamber. How it is fixed and flashed into the wall is a separate matter.
The test regime: six parts, five tests
AS 2047 calls up AS 4420 for its test methods. In the version AS 2047 references, AS 4420 is split into six parts — but only five of them are performance tests. Part 1 is general; the rating is built on Parts 2 through 6, each of which is one test.
The five tests, and what each one proves:
| # | Test | AS 4420 part | What it proves |
|---|---|---|---|
| 1 | Ultimate strength | AS 4420.6 | The window will not collapse under the site's worst wind |
| 2 | Deflection (span ratio) | AS 4420.2 | The frame bends within limits so seals and glass are not overloaded |
| 3 | Operating force | AS 4420.3 | Sashes and doors open and close without excessive force |
| 4 | Water penetration resistance | AS 4420.5 | Water is kept on the outside at the design test pressure |
| 5 | Air infiltration | AS 4420.4 | The window is tight enough to not leak draughts or energy |
Below is what each test does, with the pass thresholds written into the standard.
Test 1 — Ultimate strength (AS 4420.6)
The window assembly is loaded in both positive and negative pressure (wind pushes and sucks) to the Ultimate Limit State (ULS) pressure for its rating. The pressure is held for not less than 10 seconds.
Pass: the assembly must not collapse. This is the safety test — it answers "will it stay in the wall in a storm", not "will it look good".
Test 2 — Deflection / span ratio (AS 4420.2)
Load is applied in both directions at the Serviceability Limit State (SLS) pressure, and the deflection of every structural member (mullions, stiles, interlocks) is measured relative to its ends.
Pass thresholds in AS 2047:
- span/250 for windows and sliding doors
- span/100 for doors other than sliding
Why the difference: a hinged door carries its own weight and is pushed by people, so it is allowed to flex more; a window's seal and glass depend on the frame staying relatively stiff. A large span means a large allowable absolute deflection — which is exactly why a big sliding door needs a deeper, heavier section than a small fixed window, even at the same wind rating.
Test 3 — Operating force (AS 4420.3)
The sash or door is cycled and the force needed to open, close and latch it is measured. A unit that meets its strength and water ratings but needs a shoulder to close has still failed as a product. This test is often the one overlooked in cheap imports — and the one a homeowner notices immediately.
Test 4 — Water penetration resistance (AS 4420.5)
The window is sprayed uniformly and continuously over its exterior face at not less than 0.05 L/m²·s, while a static positive pressure — the Water Penetration Resistance (WPR) pressure for its rating — is held for 15 minutes.
Pass: no uncontrolled water reaches the inside face. Water that collects inside a drained flashing, gutter or sill is not a failure — drainage is the design working as intended. What fails is water crossing the plane of the glazing to the interior.
The WPR test is frequently the deciding test for a site: a window's overall rating is set by its lowest-performing element, and water is often that element.
Test 5 — Air infiltration (AS 4420.4)
Air leakage is measured at ±75 Pa for the "Low" level, and +75 Pa only for the "High" level.
AS 2047 air infiltration levels:
| Level | Pressure | Maximum air infiltration |
|---|---|---|
| Low | ±75 Pa | ≤ 1.0 L/s·m² |
| High | +75 Pa | ≤ 5.0 L/s·m² |
Air infiltration is a direct signal of both draughts (comfort) and energy loss (a leaky frame is a thermal hole, whatever the glass's U-value). It is also read as an early indicator of water-penetration risk: a window that leaks air will usually leak water too.
The rating: N1–N6 and C1–C4
AS 2047 classifies tested windows into ratings, each defined by three pressures — Serviceability (SLS), Ultimate (ULS), and Water Penetration (WPR). N ratings are for non-cyclonic regions, C for cyclonic regions. The rating applies to the lowest-performing element: pass strength and deflection but fail water at 150 Pa, and the unit is rated at the water limit, not the wind limit.
| Rating | SLS (±Pa) | ULS (±Pa) | WPR (+Pa) |
|---|---|---|---|
| N1 | 400 | 600 | 150 |
| N2 | 400 | 900 | 150 |
| N3 | 600 | 1400 | 150 |
| N4 | 800 | 2000 | 200 |
| N5 | 1200 | 3000 | 300 |
| N6 | 1600 | 4000 | 450 |
| C1 | 600 | 1800 | 150 |
| C2 | 800 | 2700 | 200 |
| C3 | 1200 | 4000 | 300 |
| C4 | 1600 | 5300 | 450 |
(Pressures as per AS 4055, rounded to the nearest 100 Pa. Corner ratings are higher — see below.)
Two details buyers miss: corner windows and exposure
Corner windows. AS 2047 treats a window differently when 25% or more of the width of a single panel or pane lies within 1200 mm of the building edge (a corner). Corner units are rated to a higher wind pressure, because the corner of a building sees locally amplified wind. If your project has a corner stack of glazing, specify it as a corner window — or you will under-specify it.
Exposed vs non-exposed site. The water test pressure depends on whether the site is "exposed" under the three conditions in AS 4055 (essentially: open, elevated, or coastal terrain that accelerates wind-driven rain). An exposed site demands the higher WPR figure. A window that passes at a sheltered inland site may not be rated for a headland.
What must be on the window, and on the report
AS 2047 (Clause 8.2) requires a durable label on every window assembly — not on the glazing — showing:
- the manufacturer's identification mark
- the serviceability limit state wind pressure
- the ultimate limit state wind pressure
- the water penetration resistance
And critically: the testing must be carried out by an ISO/IEC 17025-accredited laboratory — in Australia that means a NATA-accredited facility. A "test report" from an in-house factory lab, or a PDF with no accreditation number, is not the same thing.
The buyer's checklist
When a supplier quotes "AS 2047", ask for these, in this order:
- The NATA report — with the accreditation number and the exact specimen size tested.
- The rating (N1–N6 or C1–C4) and the three pressures (SLS / ULS / WPR).
- The air infiltration level — Low or High.
- Whether it is a corner or general rating for your actual unit.
- The maximum size tested — a rating only covers sizes up to what was physically tested (with the standard's extrapolation limits).
A rating you can't back up with the report is a marketing sentence. The report is the contract.
Where this fits in a Foshan buy
Australian compliance is one of the most common reasons an overseas buyer ends up with a problem shipment: a Foshan factory that has never tested to AS 2047 will quote to it anyway. Our drawing review and production monitoring specifically check that the section, the hardware, and the tested maximum size match the AS 2047 rating being claimed — because the number on the label is only worth as much as the report it points back to.