Anodised aluminium windows have a silver, metallic finish that is part of the metal itself rather than a coat of paint on top. Coetz™ offers Natural Anodised as one of five frame finishes, alongside White, Bronze, Charcoal and Black powder coat. This guide explains how anodising works, where anodised aluminium windows make sense, what they cost and how to look after them.
In this guide
What anodising is
Aluminium forms a thin oxide layer naturally when it meets air. Anodising thickens that layer in a controlled electro-chemical process, so the finish grows out of the aluminium instead of sitting on top of it. The result is a hard, metallic surface that cannot peel or flake the way a coating can.
Powder coating is different: a coloured polyester powder is sprayed on and baked in an oven. It gives you a colour choice, while anodising gives you the look of the metal.
Anodised windows versus powder coat
| Natural Anodised | Powder coat | |
|---|---|---|
| Look | Silver, metallic | Flat colour: White, Bronze, Charcoal, Black |
| How it is applied | Grown from the metal | Baked-on coating |
| Damage | Cannot chip off | A deep scratch can be touched in |
| Price | About 20% more than White | White, Bronze, Charcoal same; Black about 10% more |
Where anodised aluminium windows work
Anodised aluminium windows suit buildings where a metallic look belongs:
- Industrial and loft-style homes, where exposed metal is part of the look.
- Commercial buildings and offices that want a clean, technical finish.
- Matching older frames: many older aluminium windows were anodised, so a Natural Anodised replacement blends in on a renovation.
- Homes with steel, glass and concrete, where a coloured frame would look out of place.
If you are replacing old silver frames on part of a house, a Natural Anodised window is usually the closest match. See replace steel windows with aluminium if your existing frames are steel.
Anodised windows prices
Anodised aluminium windows cost about 20% more than White. Prices below are real shop prices on the 30.5 mm standard frame, excluding VAT, at the time of writing (October 2026).
| Window | White | Natural Anodised |
|---|---|---|
| Top hung, 600 × 600 mm, single opener | R1 481 | R1 777 |
| Top hung, 900 × 900 mm, single opener | R2 439 | R2 927 |
| Top hung, 1 200 × 1 200 mm, single opener | R3 475 | R4 170 |
| Side hung, 1 200 × 1 200 mm, 900 mm sash | R3 468 | R4 162 |
| Fixed, 1 200 × 1 200 mm, one pane | R1 858 | R2 230 |
Natural Anodised is offered on the 30.5 mm standard frame. It is not listed on the 36 mm heavy-duty versions, so check the colour options on each product page before you plan a whole house in it.
Caring for anodised windows
The finish needs no painting. Wash the frames with mild soap and water and rinse with clean water. Never use abrasive pads, scouring powder or strong alkaline cleaners, which can dull or stain the metal. In dusty or coastal areas wash more often; see how to clean aluminium windows and coastal aluminium windows.
How anodised frames age
A powder-coated frame keeps the same flat colour for years. A Natural Anodised frame keeps its metallic look, but like any bare-looking metal it can show water marks and dull slightly if it is never cleaned. Regular washing keeps the sheen. Because the finish is part of the metal, small scuffs do not peel back the way a damaged coating can.
Glass and warranty
Like every Coetz™ window, anodised aluminium windows are glazed with 6.38 mm clear laminated safety glass. The warranty is 5 years on frames, glass and powder coat, and 2 years on hardware and seals.
Ordering anodised windows
- Measure each opening in three places and use the smallest figure. See how to measure aluminium windows.
- Check that Natural Anodised is listed for the frame and window type you want.
- Match the doors: if the doors must match, check the finish is offered on the door range too.
- Plan delivery or collection.
Coetz™ supplies anodised aluminium windows only, made to order; your builder or installer fits them. We deliver nationwide, or you can collect free from Laser Park. Glazing must meet SANS 10400-N, published by the South African Bureau of Standards. For all five finishes, read aluminium window colours.
Anodised aluminium windows: frequently asked questions
What colour are anodised windows?
Natural Anodised is a silver metallic finish, the colour of the aluminium itself.
Do anodised windows cost more?
Yes. Natural Anodised costs about 20% more than White.
Do anodised windows need painting?
No. The finish is part of the metal and needs only washing. It is chosen when the window is made, so pick the finish you want to live with.
Is anodising better than powder coat?
Neither is better overall. Anodising gives a metallic look that cannot chip off; powder coat gives a choice of colours.
Is Natural Anodised available on every window?
No. It is not listed on the 36 mm heavy-duty versions, so check each product page.
Coetz™, Unit 2, 84 Ridge Road, Laser Park, Johannesburg. Call 010 412 0062, WhatsApp 076 613 4418 or use our contact page.
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