Cortizo casement
Slim frames. Big glass.
Serious performance.
Aluminium casement windows from one of Europe’s largest aluminium systems manufacturers, designed specifically for the UK — made to measure and fitted by our own team.
- 1.0
- W/m²K U-value, from
- 0.9
- W/m²K with triple glazing
- 70mm
- frame, 32mm thermal break
- Class 4
- air permeability
What makes Cortizo different
One of the deepest
thermal breaks in its class.
A 70mm frame with a deep 32mm polyamide thermal break stops heat escaping through the metal.
That means lower heating bills through a damp London winter, and a much better glass-to-frame ratio than uPVC or timber. Outward-opening, British weather tested, with PAS 24 security certification available.
Your choice of look
Standard or flush.
Standard casement — the sash sits slightly proud of the frame. Clean and contemporary, a great fit for modern homes and extensions.
Flush casement — the sash sits level with the frame for a smooth, seamless face, suiting period properties and new builds alike.
Both open outward, side- or top-hung, and combine with fixed panes, bays and shaped frames.
Where it works
Replacements, extensions, new builds.
- Direct replacement for tired timber and uPVC frames, without major structural change
- Floor-to-ceiling glazing and minimalist contemporary architecture
- Kitchen extensions, loft conversions and open-plan living
- Offices, shops and apartments
Questions
Good to know.
How energy efficient are Cortizo casement windows?
U-values start from 1.0 W/m²K, and as low as 0.9 W/m²K with triple glazing, thanks to the 32mm polyamide thermal break.
How long do aluminium windows last?
A well-made aluminium frame comfortably outlives uPVC, which can discolour and warp over time, and doesn’t rot like timber. Expect decades of service with almost no upkeep.
Do you cover my area?
We supply and install across Croydon, Thornton Heath and Greater London. Send us your postcode and we’ll confirm.
Free design consultation
Tell us about your project.
No pressure, no obligation. We'll talk through proportion, profile, colour and glass, then arrange a survey if you'd like to go further.
- Call020 3835 2583
- Mobile / WhatsApp07925 678210
- Emailinfo@4moonwindows.co.uk
- HoursMon–Fri · 08:00–17:30
Request received
Thank you.
A member of the 4Moon team will call you back to arrange your free design consultation. If it's urgent, call us on 020 3835 2583.