Guide · Wind rating & glazing check
How the wind rating and glazing check works
Every time you draw a window or door, Alumetric can look at it and answer three questions for you.
The idea in one minute
A careful friend looking over your shoulder
It knows the supplier's rule book and the building rules. You draw a window, it reads it, and it tells you: "this is fine", "this is too big for this wind" or "I need one more number from you" — and how to fix it.
Wind
Every building site has a wind rating, for example N3. A windier site needs a stronger window. The check compares your window with what the supplier says it can take.
Glass
A big pane of thin glass can bend and break in strong wind. The check makes sure the glass is thick or strong enough for its size.
Safety
Where a person could walk or fall into the glass — doors, low windows, bathrooms — the rules ask for safety glass (toughened or laminated).
What the checker needs
Four things go in, an answer comes out
The checker is only as good as the facts you give it. Watch each one light up, go into the checker, and come out as an answer.
What it checks — six simple groups
Wind rating
Does the project have a wind rating at all? Without one, the wind checks can't run.
Frame & sash limits
Is the sash or frame within the supplier's biggest allowed size for this wind?
Mullions, transoms & interlocks
Can the bars between the panes hold the wind over their length?
Glass (wind)
Is each pane strong enough for its size at this wind?
Safety glass
Doors, low glass, bathrooms: is it safety glass where it must be?
Water
Does the window keep rain out at this site? (Only when the supplier gives water figures.)
Wind rating · click a class
What does "N3" actually mean?
In Australia every house site gets a wind class: N1 to N6 in normal areas (N1 is the calmest) and C1 to C4 in cyclone areas in the north. You never work it out yourself — it is written on the builder's or engineer's plans.
ULS — in the biggest storm expected it must not break or blow in.
Wind pushing on glass is measured in pascals (Pa): 1000 Pa is about 100 kg pressing on every square metre. Alumetric already knows the pressures for every class — you only pick the class.
Step by step · watch the pointer
Set it up in 6 steps
Each step plays a short animation of the Alumetric screen. The pointer clicks for you and the matching instruction lights up. Steps 1, 2 and 4 take about a minute each.
Step 1 — Turn the check on
You do this once for your whole company.
- Click Settings — the gear at the bottom left.
- Scroll to Wind rating & glazing compliance.
- Switch on Enable wind rating & glazing compliance.
- Leave the choices as they are. For Australia they are already right: Pa, AS 4055, Australia — NCC 2022.
- Click Save compliance settings.
Step 2 — Give the project its wind rating and sill height
You do this once per job, in the project's Wind rating part.
- Open the project — on Home, ⋯ Edit (or New Project for a new job).
- Switch Not set to Rated.
- Scheme: AS 4055 is already chosen.
- Rating: pick the class from the plans — for example N3.
- Source: where you read it, for example "Engineer's report". It prints on the Glazing Certificate.
- Window sill height: the usual height of the window bottoms above the floor, for example 900. Doors don't need it.
- Save.
Step 3 — Look at the supplier's engineering data
This is the supplier's rule book: how big a sash can be at each wind class and how much wind a mullion can hold. It comes from their technical manual. If it is already loaded, you only need to look.
- Click Admin at the bottom left.
- Double-click your supplier's company.
- Open Engineering.
- Pick the Section and the Option — the window system.
- Read the two lists: Member loading tables (mullions, transoms, interlocks) and Unit limits (biggest sizes per wind class).
Step 4 — Check your glass
Three columns matter for every glass you sell.
- Open Tables › Glass.
- Kind — Annealed (ordinary), Toughened, Laminated, IGU (double glazed)…
- Safety grade — GradeA for toughened and laminated, None for ordinary glass.
- Make-up (mm) — the layers: 6, 6.38, or 4/12/4 for double glazing (4 mm glass, 12 mm gap, 4 mm glass).
- Save.
Step 5 — Draw a window and read the check
- Draw the window as usual and click Generate. The check runs by itself.
- Look at the shield button in the top toolbar. Its small mark is the answer: ✓ ! ? … ✕
- Click the shield. The Wind & glazing compliance panel opens on the right.
- If a Getting started box shows, click Open on each line until it disappears — it lists what is still missing.
- Read the verdict at the top, then the rows below it.
Step 6 — Fix problems, then print
- A red row offers fix buttons: change the glass, add a mullion or a transom…
- Italic hints, like "Choose another system", only tell you what to do — you do it yourself.
- Click a fix. Alumetric changes the window and checks it again.
- Add the window to the cart. Its card shows the verdict — click the verdict to open the window again.
- Print: the quotation shows a Wind rating line per item, the Glazing Certificate can list every window, and Window Labels prints a label per window.
| Limit | Applies at | Limits |
|---|---|---|
| Standard | AS4055 N1–N2 | H ≤ 2400 · W ≤ 1800 · ≤ 3.00 m² |
| Standard | AS4055 N3–N4 | H ≤ 1800 · W ≤ 1600 · ≤ 2.20 m² |
| Heavy-duty sash | AS4055 C1–C2 | Requires: Heavy sash |
| Name | Kind | Safety grade | Make-up (mm) | Wind capacity |
|---|---|---|---|---|
| 4mm Clear Float | Annealed | None | 4 | … |
| 5mm Clear Toughened | Toughened | GradeA | 5 | … |
| 6.38mm Clear Laminate | Laminated | GradeA | 6.38 | … |
| Low-E Double Glazed | IGU | None | … |
Try it yourself
Play with the checker
Change the window, the glass, the wind class or the sill height and watch the answer change. The fix buttons work too — click one.
The site
The window
What's on file
Reading the answer
What each verdict means — and what to do
The verdict sits on the shield button, at the top of the panel and on each cart card. There are only six.
Compliant
Everything that could be checked passed.
Compliant (indicative)
It passed, but at least one figure was calculated by Alumetric because there was no supplier chart for it.
Review
It passed, but something deserves a look — for example a full-height pane needs a manifestation band (a strip so people see the glass).
Needs input
Alumetric needs one more fact from you — usually the sill height.
Not rated
Nothing could be checked: the project has no wind rating, or the system has no supplier data.
Not compliant
Something is too weak, too big, or the wrong glass.
And "2 unchecked"?
Unchecked never makes a window fail. It only means "I couldn't check this part". Add the supplier's data in Admin › Engineering and the number goes away.
Safety glass · move the slider
Why the sill height matters
Glass that starts low down can be walked into, so it must be safety glass. The sill height is how high the bottom of the window is above the inside floor. Alumetric draws the window, not the wall, so it can't measure this — you tell it once per project.
• Doors — always safety glass.
• Glass starting below 500 mm — safety glass (small panes of thicker ordinary glass can be allowed).
• Bathrooms, ensuites and showers — safety glass below 2000 mm.
• A pane right next to a door — safety glass.
• A big full-height pane that looks like an open doorway — safety glass and a manifestation band.
A tour of the panel
The panel, piece by piece
Click a number, or a line on the right, to see which part of the panel it is.
Common questions
Questions people ask
Do I have to use it?
No. It is off until you turn it on in Settings. While it is off, nothing about it shows, not even the shield button on the Production page, and Alumetric works as before.
Will it stop me saving or quoting a window?
Never. It only gives advice. You can save, quote and print a window that fails. You decide.
Why does every window say "Needs input"?
It doesn't know the sill height. Open the project and fill in Window sill height once — for example 900. Every window of the job uses it. Doors don't need it; they stand on the floor.
Why does it say "Not rated"?
One of two reasons, and the panel tells you which: the project has no wind rating (button: "Set the project's wind rating"), or the window system has no supplier data (button: "Open Admin › Engineering"). Fill it in once and every window of that system is checked.
What does "indicative" mean?
There was no supplier chart for that part, so Alumetric calculated an estimate itself. It is a good guide for quoting, but confirm with the supplier before you build.
I changed the project's wind rating. Do I redo every window?
No. The cart checks every saved window again by itself. You can also click Re-check wind rating at the top of the cart.
One window is in a bathroom, or near a corner of the building. What do I do?
Open the panel, then This item. Type the room, for example "Bathroom", or set Wet area to Yes. "Corner window" and "Exposed site" appear there when the wind scheme uses them.
Where does the supplier data come from?
From your supplier's technical manual: tables of sizes and wind pressures. You can enter it in Admin › Engineering, bring it from another computer with Import, or send the manual to Alumetric and we'll help set it up.
Is this a certificate?
No. It is an advisory check based on the data entered. The supplier and the engineer certify. The Glazing Certificate you print is your own statement, helped by these checks.
Little dictionary
The words, in plain English
Your five-minute checklist
Tick them off as you go.
- Settings — turn on Wind rating & glazing compliance, then Save.
- Project — Wind rating: Rated, AS 4055, the class from the plans (for example N3).
- Project — Window sill height (for example 900).
- Production — Generate a window and open the shield. If it says "No engineering data", click Open Admin › Engineering.
- Tables › Glass — double-glazed units have a make-up (for example 4/12/4).
- Done. The shield shows ✓ and the Getting started box has gone.
Need a hand setting it up?
Send us your supplier's technical manual or ask a question — we're happy to help.
The wind rating and glazing check is advisory. It relies on the data and settings entered — supplier tables, glass data, the wind rating and the built-in settings — and does not replace the supplier's or an engineer's certification, or the codes that apply where you build. Supplier, system and customer names on this page are examples.
The safety-glass rules described here are based on the National Construction Code 2022. The National Construction Code 2022 was provided by the Australian Building Codes Board under the CC BY 4.0 licence.