Side hung window designs differ in how many sashes open, how tall each sash is and which frame carries them, and the right combination depends on how much air the room needs and how much space there is outside for the sash to swing. Coetz™ makes side hung aluminium windows as single and twin openers, with three sash heights and two frame depths. This guide explains each option, compares prices at the same size and helps you choose.
In this guide
How a side hung window works
The sash is hinged on one side on stainless steel friction stays and swings outwards like a small door. Because it opens almost the full height of the sash, a side hung window lets in more air than a top hung window of the same size, and you can reach much of the outside glass from inside. Restrictor stays, which limit how far the sash opens, are available on request. See aluminium window hinges.
Single opener or twin opener
The first choice in side hung window designs is how many sashes open.
Single opener
One opening sash, with fixed glass making up the rest of a wider window. It suits bathrooms, kitchens and bedrooms, and it is the lowest-priced layout.
Twin opener
Two opening sashes in one frame, from 1 200 to 2 400 mm wide. It doubles the airflow across a wide window, which suits living rooms and bedrooms that need cross-ventilation.
Three sash heights
Most side hung window designs come with a choice of sash height:
- 900 mm: the everyday choice, with more fixed glass below on taller windows.
- 1 200 mm: a taller opening for more air.
- 1 500 mm: the tallest, made in the 36 mm heavy-duty frame only.
A single opener on a cill, 600 × 2 100 mm, suits a tall, narrow opening beside a door or in a stairwell.
Two frame depths
Side hung window designs come in two frame depths. The 30.5 mm standard frame suits most homes. The 36 mm heavy-duty frame is deeper and stiffer, for larger sashes and exposed walls, and costs roughly 9% more. Natural Anodised is not made in the 36 mm frame. See aluminium window frames.
Side hung window designs compared on price
All 1 200 × 1 200 mm, White, excluding VAT, at the time of writing (October 2026):
| Design | Price |
|---|---|
| Single opener, 900 mm sash | R3 468 |
| Single opener, 1 200 mm sash | R3 933 |
| Single opener, 1 200 mm sash, 36 mm frame | R4 287 |
| Twin opener, 900 mm sash | R4 600 |
| Twin opener, 1 200 mm sash | R5 494 |
Black costs about 10% more; Natural Anodised about 20% more on the 30.5 mm frame.
Side hung or top hung?
Choose side hung for maximum airflow and easier cleaning. Choose top hung where the window faces the rain, because a top hung vent sheds water while it is open. Many houses use both: side hung in bedrooms and living areas, top hung in bathrooms and on exposed walls. See top hung vs side hung windows and top hung window designs.
Choosing a design
These five points narrow down side hung window designs quickly:
- Airflow. One sash for a small room, two for a wide one.
- Sash height. 900 mm for most rooms; taller for more air.
- Swing space. The sash opens outwards, so keep paths and walkways clear.
- Frame. 36 mm for big sashes or exposed walls.
- Colour. Match the rest of the house.
Hardware, glass and ordering
All side hung window designs come with stainless steel friction stays and black wedgeless handles; natural and white handles are also available. See aluminium window handles. 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 side hung aluminium windows and side hung window sizes.
Side hung window designs: frequently asked questions
What is the difference between a single and twin opener?
A single opener has one opening sash; a twin opener has two sashes in one frame for more airflow.
Which side hung design is cheapest?
The single opener with a 900 mm sash, from R1 946 excluding VAT for 600 × 900 mm in White.
Do side hung windows open outwards?
Yes. The sash is hinged on one side and swings outwards like a small door.
Can I limit how far a side hung window opens?
Yes. Restrictor stays are available on request to limit how far the sash opens.
When do I need the 36 mm frame?
For the 1 500 mm sash, and for large sashes or exposed walls where a stiffer frame helps.
Coetz™, Unit 2, 84 Ridge Road, Laser Park, Johannesburg. Call 010 412 0062, WhatsApp 076 613 4418 or use our contact page.
Compare with sliding windows: casement vs sliding windows.
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