Standard door and window sizes in Australia

The door leaf and window sizes Australian homes are actually built to, why 870mm has quietly replaced 820mm as the sensible default, and the clear-width rule that catches people out.

Doors and windows are ordered from a schedule, and the schedule comes off the plan. Get the sizes wrong on the plan and you either pay for custom units or lose the room to a doorway that doesn't work.

Here are the sizes to draw with, and the one rule that changes the answer from what most older guides say.

The clear width rule, first

This is the thing that catches people.

A door's nominal size is the leaf: an "820 door" is a leaf 820mm wide. A door's clear width is the actual gap you can pass through once the leaf is open, and that's smaller, because you lose the door stop, the hardware, and the thickness of the open leaf itself. An 820 leaf gives roughly 770mm clear.

Since 1 October 2023, the Livable Housing Design Standard has applied to new Class 1a dwellings, and it asks for 820mm clear at the entry-level doorways it covers. An 820 leaf does not deliver 820 clear. The next standard Australian size up that does is 870.

The practical upshot: draw internal doors at 870, not 820, unless you have a specific reason not to. That's the default Draftie uses, for exactly this reason.

Requirements vary by dwelling class, state adoption and which doorways are in scope, so treat this as the reason to check rather than as your certification advice. Your building certifier is the authority on your project.

Internal door sizes

Australian door leaves come in standard widths, all normally 2040mm high:

Height: 2040mm is standard. 2340mm and 2400mm leaves are available and increasingly common where ceilings are 2700mm: a 2040 door under a 2700 ceiling can look stumpy.

Other internal types:

• Cavity slider: same leaf widths, but the wall needs to be a cavity unit roughly twice the door width long, and you can't put a power point or a stud-fixed shelf in that wall. Plan the wall, not just the door.
• Sliding door (surface): the leaf runs on the face of the wall; cheap, and it needs the same clear wall length beside the opening.
• Bifold: for robes and linen; two or four leaves.
• Cased opening, no door at all. A 1200mm cased opening between kitchen and living is common and costs nothing but the lining.

Entry doors

Wider and heavier than internal doors:

• Width: 870mm or 920mm are common; 1020mm and 1200mm for a feature entry.
• Height: 2040mm standard, 2340mm for a taller entry, and full-height 2400mm on higher-ceiling builds.
• Double entry / with sidelight: a 920 leaf plus a 400–500 sidelight, or a pair of 820s.

The entry door is one of the doorways the Livable Housing standard is most concerned with, so the clear-width point applies here first.

External sliding and stacker doors

Where the living area meets the alfresco. These are ordered as units, not leaves:

• 2-panel slider: around 1800mm wide overall, the sensible minimum, and only one panel actually opens, so the clear opening is about half.
• 3-panel: around 2400–2700mm.
• 4-panel: around 3000–3600mm. This is the common "open the living room to the deck" size.
• Stacker (3 or 4 panels stacking one side): 2700–3600mm, with a much larger clear opening than a slider of the same width.
• Bifold: 2400mm up, opening almost the full width, the largest clear opening for a given size, and the most expensive.

Height: 2100mm is the common sliding-door height; 2400mm where the ceiling allows it.

The number to care about is the clear opening, not the overall width. A 3600mm four-panel slider opens about 1800mm. A 3600mm stacker opens about 2700mm. Same hole, very different door.

Garage doors

• Single: 2400–2700mm wide, 2100–2400mm high.
• Double: 4800–5500mm wide, 2100–2400mm high. 4800 is the common project-home figure.

Height matters more than people expect: a 2100mm door will not admit a roof-racked 4WD or a caravan.

Remember the garage opening is not the garage. A single garage wants about 3600 × 6000mm clear internally, and a double about 5500 × 6000mm, to take cars plus open doors plus the bikes that end up along one wall.

Window sizes

Windows are made to order in most of Australia, so "standard" means common, not only available. Sizes are quoted width × height, in millimetres.

Common heights: 600, 900, 1200, 1500, 1800, 2100. Common widths: 600, 900, 1200, 1500, 1800, 2400.

Typical combinations by room:

Sill height is the dimension a plan doesn't show, and the one that decides whether a window works. 900mm clears a bedside table and a bench; 600mm suits a living room; a bathroom wants it high enough for privacy.

Two constraints worth knowing:

• Fall protection. Where a bedroom window's opening is high enough above the outside ground, the NCC restricts how far it can open or requires a barrier. This affects upper-floor windows especially: check it rather than assuming.
• Ventilation and light. Habitable rooms need openable window area for ventilation and glazed area for light under the NCC, expressed as a proportion of floor area. A big room with one small window can fail.

Getting them onto the plan correctly

What the schedule needs from your drawing, per opening: type, nominal width, height, sill height for windows, which way it swings or slides, and the room it serves.

Draftie's defaults are the sizes above: 870 internal doors, 2040 high, 1800 windows at a 900 sill, a 4800 garage door, and each opening's width, height, sill and swing are editable per opening, so the plan you export carries the schedule rather than implying one.

FAQ

What is the standard door size in Australia?

An internal door leaf is traditionally 820mm wide and 2040mm high. 870mm is now the better default, because the Livable Housing Design Standard asks for 820mm clear at the doorways it covers, and an 820 leaf only gives about 770mm clear.

What is the difference between nominal and clear door width?

Nominal is the leaf size you order. Clear is the gap you can actually walk through once it's open, after the stop, the hardware and the leaf thickness: roughly 50mm less than nominal.

What is the standard window sill height?

900mm is the most common, and it suits bedrooms and kitchens because it clears bedside tables and benchtops. Living areas often go lower at 600mm for the view, and bathrooms higher at 1500mm+ for privacy.

What size is a standard double garage door?

4800mm wide is the common Australian project-home size, with 5500mm also used. Heights are 2100mm or 2400mm: take 2400mm if you have anything tall.

Are Australian window sizes standard or made to order?

Most Australian windows are made to order, so the "standard" sizes are simply the common ones. Sticking near them is usually cheaper and faster, but a non-standard size is not the problem it is in some markets.

How wide should a sliding door to the alfresco be?

Think in clear opening rather than overall width. A 3600mm four-panel slider opens about 1800mm; a stacker the same width opens about 2700mm; a bifold opens nearly the full width. Choose the mechanism for the opening you want, then the size.

Related guides

General information for Australian residential projects, not professional advice. Product specifications and prices change, confirm current details with the manufacturer or supplier before you rely on them. Draftie produces concept plans, not construction documents.