020 341 10038/ 01768 254552/ projects@thefenestrationnetwork.co.uk
020 341 10038/ 01768 254552/ projects@thefenestrationnetwork.co.uk

Call us: 020 341 10038 | 01768 254552
Email: projects@thefenestrationnetwork.co.uk
The GW70 (Cortizo) window system is a premium slimline aluminium window solution offering outstanding thermal performance, minimal sightlines, and modern architectural styling. Ideal for high-end residential and commercial projects where sleek aesthetics and high efficiency are essential.


GW70 is a high-performance 70mm aluminium window system developed around Cortizo's engineering principles. It delivers slimline profiles, superb insulation values, and outstanding durability — making it a superb choice for design-led builds and renovations.
Whether you're upgrading a contemporary home, adding a glass extension, or specifying windows for a new build, this system offers a clean, modern finish with a superior feel.

Frame depth - 70mm slimline system
Sightlines - Minimal frame, large glazed area
Thermal performance - Low U-values (dependent on glazing spec)
Glazing options - Double, triple, acoustic, solar control
Security - PAS 24 compatible / multi-point locking
Colour finishes - 150+ RAL colours, dual colour available
Opening types - Casement, tilt & turn, fixed, large picture windows
Design style - Contemporary slimline aluminium



The GW70 system is perfect for:

We offer a complete service:
We can also coordinate with your architect, builder or structural contractor for larger projects.

We supply and install the GW-70 aluminium window system by Cortizo nationwide. Whether you’re upgrading windows for better thermal efficiency, replacing for aesthetics, or specifying for a new build, our installation teams cover all major UK regions with care, expertise and full service support.
South & South East
GW-70 Windows London, Kent, Surrey, Sussex, Hampshire, Southampton, Home Counties and Essex.
From modern townhouses in London to coastal homes in Sussex and countryside retreats in the Home Counties, our South & South East team deliver full-service supply, installation and after-care.
South West & West
GW-70 Windows Devon, Bristol and Gloucester.
In the South West region we support both period home replacements and contemporary aluminium window installs, ensuring the GW-70 system meets the highest performance and finish standards.
Midlands & Central
GW-70 Windows Birmingham, The Midlands, Northamptonshire, Nottinghamshire, Leicestershire, Derbyshire and Lincolnshire.
Our Midlands network provides efficient lead-times, detailed surveys and professional installation of the GW-70 system across domestic and commercial projects.
North West
GW-70 Windows Greater Manchester, Manchester, Lancashire, Liverpool, Cheshire, Cumbria and Carlisle.
From city apartments to countryside homes, we supply and fit the GW-70 system with regional expertise and full warranty support across the North West.
Yorkshire & North East
GW-70 Windows Yorkshire, Newcastle and the North East.
Whether you’re renovating a property in Yorkshire or fitting windows in the North East region, our team installs the GW-70 system with full specification options, high-end finishes and professional service.
Ready to Transform Your Property?
If you’re looking for GW-70 Windows to be supplied and installed in your region, contact us today for a free site survey and quote. Our team will walk you through sizing, configuration (casement, tilt & turn, shaped options), colour finishes, hardware choices and installation timeline.
projects@thefenestrationnetwork.co.uk 020 341 10038 South of England 01768 254552 Rest of UK


ASK FOR OUR WHITE GLOVE PROJECT SERVICE - FULL SUPPLY, SURVEY AND INSTALLATION
Ultra-slim 88mm sightlines
Available with or without Crittal effect
Over 150+ RAL colours to choose from
U-Value: 1.0W/M2K
Available in over 19 configurations

ASK FOR OUR WHITE GLOVE PROJECT SERVICE - FULL SUPPLY, SURVEY AND INSTALLATION
132mm sightlines
Over 150+ RAL colours to choose from
Upto 20 Years Guarantee
U-Value: 1.4W/M2K
Available in over 19 configurations

ASK FOR OUR WHITE GLOVE PROJECT SERVICE - FULL SUPPLY, SURVEY AND INSTALLATION
Ultra slim 20mm sightlines (Central mullion)
Soft Close
Over 200+ RAL colours to choose from
Available in 2 or 3 track
1.6 W/m2K U Value

ASK FOR OUR WHITE GLOVE PROJECT SERVICE - FULL SUPPLY, SURVEY AND INSTALLATION
Sightlines
Frame depth 116 mm / 182 mm 3 rails Sash depth 37 mm
Interlock 20 mm

ASK FOR OUR WHITE GLOVE PROJECT SERVICE - FULL SUPPLY, SURVEY AND INSTALLATION
Slim 20mm sightlines
Standard or Flush Stacking
Over 200+ RAL colours to choose from
1.3 W/m2K U Value

ASK FOR OUR WHITE GLOVE PROJECT SERVICE - FULL SUPPLY, SURVEY AND INSTALLATION
110mm sightlines
Over 150+ RAL colours to choose from
Upto 20 Years Guarantee
0.8Wm2K U-Values
Available in upto 14 panes width

ASK FOR OUR WHITE GLOVE PROJECT SERVICE - FULL SUPPLY, SURVEY AND INSTALLATION
Highly practical, affordable range of Aluminium Windows available in a range of colours and designs.
Aesthetically pleasing and simple to install.

ASK FOR OUR WHITE GLOVE PROJECT SERVICE - FULL SUPPLY, SURVEY AND INSTALLATION
Door leaves up to 3m high
Stunning Heritage (Crittal effect)
Can be used external and internal
Inward or outward opening

ASK FOR OUR WHITE GLOVE PROJECT SERVICE - FULL SUPPLY, SURVEY AND INSTALLATION
Highly practical, affordable range of Aluminium Windows available in a range of colours and designs.
Aesthetically pleasing and simple to install.

ASK FOR OUR WHITE GLOVE PROJECT SERVICE - FULL SUPPLY, SURVEY AND INSTALLATION
Fresh, vibrant designs.
Our range of Entrance doors are excellent quality, available in a variety of styles.
Quick lead times and a dream to install.

ASK FOR OUR WHITE GLOVE PROJECT SERVICE - FULL SUPPLY, SURVEY AND INSTALLATION
Explore Aluspace internal doors and screens – slim, stylish steel-look glazing from Smart Systems, designed to transform modern homes.

Extensions, Orangeries, Building works around the Glazing.
Integrate Building and Glazing in one for a seamless project.




The Fenestration Network are Nationwide Supply and Installation experts in:
Bi Folding Doors/ Sliding Doors/ Entrance Doors/ Windows/ Garden Studios, Glass Balustrades, Orangeries.
Our teams have over 35 years experience supplying and installing quality Glazing products across the UK. We have teams of Surveyors, Installers and Technical Experts close to you to help guide you through your project.
We cover all regions on this map with our professional and highly skilled , local surveyors and installers.
020 341 10038 - South
01768 254552 - Rest of UK
The Fenestration Network
projects@thefenestrationnetwork.co.uk
Copyright © 2023 The Fenestration Network - All Rights Reserved. The Fenestration Network is a trading style of Evans Sales Group Ltd. All insurances are available to view upon request.
Our November 10% discount applies to all orders placed before 30th November 2025, applicable only to quotes produced from 15th October 2025.
We aren't CPS scheme registered ourselves but a lot of our installers are. If you require a CPS sign off please let us know at quoting stage and we can add this in to the quote. If you don't ask us for CPS sign off then it is expected that you will arrange yourselves with building control at your local council.

Applicable only to orders resulting from new quotes produced from 15th October to 30th November, must include full supply, survey and installation and must include any combination of the below:
Windows/ Bi Folding Doors/ Sliding Doors/ French Doors/ Entrance Doors/ Windows/ Garden Studios, Glass Balustrades, Orangeries.