If you are pricing a window job, the first thing worth knowing is that aluminium windows Cape Town homeowners buy fall into two very different price brackets: the frame on its own, and the frame supplied and fitted. Mixing those two up is the single most common reason a quote looks higher than expected.
This guide sets out both, using prices visible from South African suppliers in 2026. Every figure here is a range, because size, glazing and the state of the opening move the number more than anything else.
What aluminium windows cost in Cape Town in 2026
Standard off-the-shelf frames from the big retailers give you the floor price. A 600 x 900 bronze frame sits at roughly R1,050 to R1,100. A 1200 x 1200 unit runs about R1,200 to R1,250. Casement units in the 30.5mm section from specialist manufacturers range from around R1,330 to R1,970 depending on the configuration.
Those are frames only. They do not include glass upgrades, removal of the old window, making good the brickwork, sealing, or labour.
For supplied and fitted sliding windows in Cape Town, published ranges sit at roughly R1,500 to R4,000 per window. Larger stacking and folding door systems are quoted per square metre and climb well beyond that.
What actually moves the price
Five things do most of the work on a quote:
- Size. Price rises with the square metre, not the unit. A single large window can cost more than three small ones.
- Section. The heavier 38mm sections cost more than the standard 30.5mm, and are worth it on bigger spans.
- Glazing. Single glazing is standard here. Laminated or double glazing adds meaningfully to the cost.
- Opening type. Fixed panes are cheapest. Side-hung, top-hung, sliding and folding each add cost in that order.
- The opening itself. Replacing like for like is quick. Widening a brick opening means lintels, structural work and making good.
Frame only or supplied and fitted
Buying the frame yourself and finding a fitter looks cheaper on paper. It often is not.
Retail frames come in fixed standard sizes. Older Cape Town homes rarely have standard openings. If the frame does not fit, you are paying someone to cut brickwork to suit the window, which is the wrong way round.
A fitted quote is measured to your actual opening. It also puts one person in charge of the seal, which matters a great deal in a wind-driven rain climate.
Why aluminium suits the Cape
Aluminium does not rot, warp or need sanding and repainting the way timber does. Powder-coated frames handle salt air far better than untreated steel.
That matters more the closer you are to the coast. Southeaster-driven rain finds every weak seal on a west-facing wall, and a frame that swells and shrinks with the seasons will eventually leak.
The trade-off is thermal performance. Aluminium conducts heat, so a large unglazed aluminium window on a north face will let more heat in than a timber equivalent. Good shading and the right glass deal with that.
Getting a quote that holds
Ask for the frame size, the section, the glass specification and the opening type in writing. A quote that lists only “aluminium window” gives you nothing to compare.
Check whether removal of the old frame, disposal, sealing and making good the plaster are included. On a replacement job these are real costs and they are where quotes quietly diverge.
We install and maintain aluminium doors and windows across Cape Town, and quotations are free with no obligation. You can see completed work in our project gallery or read about our full range of services.
If you are weighing up materials before you commit, our comparison of aluminium against wooden windows covers the long-term cost side in more detail. For homes near the sea, the coastal maintenance guide is worth a read too.
What aluminium windows Cape Town suppliers include in a price
Two quotes for the same house can differ by thousands simply because of what sits inside the number. Ask every supplier to confirm, in writing, whether the price covers removal and disposal of the old frame, the lintel if the opening changes, sealing, and plaster made good inside and out.
Handles, locks and stays are another quiet variable. Budget hardware on an otherwise good frame is a false economy, because the moving parts are what fail first. On a coastal-facing elevation the hardware specification matters as much as the frame, something we cover in the coastal maintenance guide.
Planning a whole-house replacement
Doing every window at once is cheaper per unit than doing them one at a time. The team is already on site, the scaffolding is up, and the plasterer comes once instead of five times.
If the budget will not stretch, stage it sensibly. Start with the elevations taking the most weather, usually the west and south faces, and the windows that already stick or leak. Leave sheltered rooms for a later phase.
Where windows are part of a wider project, it pays to sequence them with the other trades. Our renovation cost guide sets out how the trades stack up on a full job.
Frequently asked questions
How much do aluminium windows cost in Cape Town?
Frames on their own start at roughly R1,050 for a small 600 x 900 unit and around R1,200 for a 1200 x 1200. Supplied and fitted sliding windows are commonly quoted between R1,500 and R4,000 per window. Size, glazing and the condition of the opening move the final figure most.
Are aluminium windows cheaper than wooden ones?
Aluminium is usually cheaper to buy and much cheaper to own. Timber costs more over time because it needs sanding, sealing and repainting every few years, especially near the coast.
Do aluminium windows rust in coastal areas?
Aluminium does not rust like steel. It can suffer surface pitting in salt air if it is never cleaned. Rinsing the frames with fresh water a few times a year prevents almost all of it.
How long does it take to replace a window?
A straight like-for-like replacement is usually a few hours per window. If the opening has to be widened or a lintel added, allow a day or more and expect plaster repairs afterwards.
Can I supply my own frames and have you fit them?
Yes, though we usually advise against it. Retail frames come in fixed sizes and older Cape Town openings rarely match, which means cutting brickwork to suit the frame instead of the other way around.
