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bullet-proof window and glass curtain wall in a modern building


When you need the highest levels of security, anti-burglar qualities and weather resistance, choose the CS77 door from Prestige Aluminium Bi-Folds in Bootle, Liverpool.

Bi-Fold Doors: Welcome

The ConceptSystem 77 collection

CS77 is a thermally broken, multi-chambered system for windows and doors that offers excellent levels of security, weather resistance and thermal insulation.


Some extreme situations require bullet resistance, and this variant offers it in various classes. However, it is just as suited to residential settings as it is to high-security commercial ones.

The CS77 system offers a comprehensive range of inward-and-outward-opening window and door designs, which come available in three different styles, making it an incredibly versatile choice for any setting. Choose from a variety of colours and finishes – you can even have a different colour inside and out!

The fibreglass-reinforced polyamide strips and weather gaskets are designed with ribs and hollow chambers to achieve superior thermal insulation levels.

Reynaers CS77 doors
Bi-Fold Doors: About
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  • Whole window U-values as low as 0.94 W/m2K

  • Up to 600 Pa air-tightness

  • Up to 900 Pa water-tightness

  • Up to 2000 Pa wind load resistance

  • RC2 and even RC3 security with UK Secured By Design security, PAS 24:2016 or BS7950 depending on window type

Style Options

Three different style options are available, including the traditional Renaissance style and the clean, contemporary lines of the hidden vent style.

Bi-Fold Doors: Image

Bullet-proof testing the CS77

You want security? You've got it!


The CS77 isn't just weatherproof, vandal proof and burglar proof. It's also bullet proof!

Bi-Fold Doors: Testimonials

For windows and doors that merge thermal efficiency with maximum security, contact Prestige Aluminium Bi-Folds

Bi-Fold Doors: Contact
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