Aluminium Sliding Window Sizes

Aluminium sliding window sizes at Coetz™ run from a 900 × 600 mm 2 panel window up to a 4 800 mm wide 4 panel window, in heights from 600 to 1 800 mm. Widths go up in 300 mm steps, and there are three sliding systems at different price levels. This guide sets out the full size range, how panel count relates to width, prices for common sizes and how to choose.

How sizes are written

Aluminium sliding window sizes are written as width × height in millimetres. The size is the catalogue size; the actual frame is 10 mm smaller each way, which leaves room to fit it into the opening. Measure the opening in three places each way and use the smallest reading; see how to measure aluminium windows.

The size range by panel count

Layout	Widths (mm)	Heights (mm)
2 panel	900 to 3 000	600 to 1 800
3 panel	1 800 to 4 500	600 to 1 500 (1 800 on Premier and Horizon)
4 panel	1 800 to 4 800	600 to 1 500 (1 800 on Premier and Horizon)

A 2 panel window has two panels in one frame. Across aluminium sliding window sizes, a 3 or 4 panel window spreads a wide opening across more, narrower panels, which keeps each panel a manageable weight.

Three sliding systems

All aluminium sliding window sizes are offered in three systems:

• Standard: the economical choice, with a flush sliding lock handle.
• Premier: a slimline system with a hook lock, also available with Y-Louvre inserts.
• Horizon: a heavy-duty system with a hook lock and stainless steel flush pull handle.

Aluminium sliding window sizes and prices

2 panel, White, excluding VAT, at the time of writing (October 2026):

Size (mm)	Standard	Premier	Horizon
900 × 600	R3 192	R8 680	R7 321
1 200 × 900	R4 318	R10 765	R8 919
1 200 × 1 200	R4 952	R11 948	R9 863
1 800 × 1 200	R6 108	R13 917	R11 442
2 400 × 1 200	R7 260	R15 884	R13 013

On the Standard system, a 3 panel window is R7 420 and a 4 panel R8 018 at 1 800 × 1 200 mm. Bronze and Charcoal cost the same as White; Black costs about 10% more and Natural Anodised about 20% more.

Common sizes by room

These aluminium sliding window sizes suit most rooms:

• Kitchen above a counter: 1 200 × 900 or 1 500 × 900 mm. See aluminium kitchen windows.
• Bedroom: 1 200 × 1 200 or 1 500 × 1 200 mm.
• Living room: 1 800 × 1 500 mm and wider, often 3 or 4 panel.
• Passage or garage: 900 × 600 mm. See aluminium garage windows.

Choosing the right size

Use these steps to pick between aluminium sliding window sizes:

1. Measure the opening and take the smallest reading.
2. Choose the nearest standard size just below it.
3. Choose the panel count. Wider windows read better as 3 or 4 panels.
4. Choose the system for your budget and how much use the window gets.
5. Pick the colour and order.

If your opening falls between sizes, ask us before you order; see aluminium window sizes and large aluminium windows.

Glass and ordering

Every window uses 6.38 mm clear laminated safety glass to SANS 10400-N, published by the South African Bureau of Standards. Coetz™ supplies the windows ready to fit; your builder or installer fits them. We deliver across South Africa, or you can collect free from Laser Park. See all aluminium sliding windows.

Aluminium sliding window sizes: frequently asked questions

What is the smallest aluminium sliding window?

The smallest is a 900 × 600 mm 2 panel window, from R3 192 excluding VAT on the Standard system in White.

What is the largest sliding window?

A 4 panel window goes up to 4 800 mm wide, and Premier and Horizon windows go up to 1 800 mm high.

Is the frame the same size as the catalogue size?

No. The actual frame is 10 mm smaller than the catalogue size each way, to leave fitting room.

When should I choose 3 or 4 panels?

For openings wider than about 1 800 mm, where more, narrower panels are lighter to slide.

Which sliding system is cheapest?

The Standard system, which costs well under half the price of Premier at most sizes.

Coetz™, Unit 2, 84 Ridge Road, Laser Park, Johannesburg. Call 010 412 0062, WhatsApp 076 613 4418 or use our contact page.