FGS Heritage 47 Slim Frame Windows

FGS Heritage 47 Crittal Replacement Window System

This slim window system has been designed to offer a modern solution for heritage and renovations applications where the requirement to replace old steel windows is essential.

FGS Heritage 47 provides the ideal solution for heritage applications such as listed building renovations and large-scale replica-refurbishment projects where planning constraints are to be considered.

It is a high-performance window system with innovative polyamide thermal break technology which creates a barrier between the cold air outside and the warm air inside. This technology significantly reduces thermal transmittance and enhances the overall U Value of a product and is designed to meet the exacting requirements of Document L 2010.

The window is designed to be built as a series of horizontal modules which can be stacked using horizontal couplers to form a multi-part window featuring a specially design drip bar between modules.

FGS Heritage 47 has been tested to PAS 24:2012 for casement windows and fixed lights.

 • Fixed windows
 • Single or double sash, side hung open out casements
 • Top hung open out casements
 • Polyamide thermal break provides enhanced thermal performance
 • Designed as a direct replacement for steel windows


WER Rating: B
U Value: 1.5W/m²K (using 1.0W/m²K glass unit) 
Air: Class 4, 600Pa
Water: Class 9A, 600Pa
Wind: Class AE, 2400Pa Document
L Compliant: Yes
Kitemark: Yes
BS 6375-1:2009: Yes
BS 4873: Yes


Side Hung Max Width: 700mm
Side Hung Max Height: 1400mm
Side Hung Max Weight: 40kg
Top Hung Max Width: 1400mm
Top Hung Max Height: 1300mm
Top Hung Max Weight: 35kg
Single Door Max Width: 900mm
Single Door Max Height: 2100mm. But Fixed elements can be added above the doors to increase the overall height
Glazing: 24mm, 28mm, 32mm & 36mm double or triple glazed units
Frame Depth: 47mm
Typical Sightlines: 59mm