Steel Framed Glass Facades

Steel Framed Glass Facades

The 4F1 Curtain Walling system is an impressive architectural glazing system that can be used to create large and impressive elevations of self-supporting glass with a beautifully minimal finish. 

This minimally framed façade system allows us to create thermally broken structural mullions in steel, stainless steel or corten steel with extremely minimal framing sections.

The frames used on the Secco 4F1 system can be designed in numerous variations, creating the perfect look for any residential or commercial project. The windows and doors in this system can guarantee you with the very best performance.

This 4F1 system includes the incredible thermal break technology for a curtain walling system with mullions and transoms with structural sections of depths from 50mm to 180mm and a frame size width of only 50mm.

An insulating glass unit of up to 56mm thick can be integrated within these large thermally broken glass facades in order to achieve high levels of thermal insulation.  

The Secco 4F1 system performance has been tested by the best certification laboratories in Europe in conformity with the standard EN 13830 regulations.

Frame Sizes

Frame Face Width 50mm

Frame Depth 50-180mm


Various Secco windows and doors are able to be integrated into the minimal metal framing

Maximum Sizes

Maximum Glass Weight 550kg


Thermal Performance  Uf > 0.8 W/m2K in accordance with EN ISO 10077-2 (using Typical section PZ3610)

Air Permeability Class AE in accordance with EN 12152

Water Tightness Class R1500 in accordance with EN 13050

Resistance to Wind Load up to 2000 Pa in accordance with EN 14019

Impact Resistance Class I5/E5 in accordance with EN 14019)


Double or triple glazing, 25-56mm thick

Glass Specification

Double or triple glazing, 25-56mm thick

Glass Options

Low Iron Glass, Anti Reflective Glass, Solar Control Glass, Acoustic Reduction Glass, Translucent Glass, Electro Chromic Glass, Heated Glass

Featured Projects

Contact Us

Showroom Address
The Courtyard Showroom,
Sky House,
Raans Road,
HP6 6JQ,
United Kingdom

Factory Address
Units 8 & 9 Nazeing Glass Works Estate,
Nazeing New Road,
EN10 6SU,
United Kingdom



+44(0)1494 722 880

IQ Metal are at the forefront of bespoke metal work and steel window fabrication. Our state of the art factory and desire to create beautiful products allow us to work on some of the most prestigious architectural projects in the country. We pride ourselves on customer service so please contact us immediately if you have any queries or questions about any of our luxury steel windows and doors.