GS20 Cortizo Sliding Doors | Ultra Slim 20 mm Interlock Aluminium Sliders
Call us: 020 341 10038 | 01768 254552
Email: projects@thefenestrationnetwork.co.uk
Experience a new level of glazing elegance with the GS20 sliding door system — combining ultra-slim profiles, advanced performance, and versatile design configurations.
What Is the GS20 Sliding Door System?
The GS20 is a structurally bonded aluminium sliding solution (based on Cortizo engineering) that offers a 20 mm central interlock (sightline), enabling expansive glazed areas without heavy frame intrusion.
It’s ideal for both renovation and new build projects, delivering a sleek modern aesthetic while satisfying thermal, security and durability requirements.
Key Features & Technical Specifications
FeatureDetail / CapabilitySightline / Interlock 20 mm centre interlock for slim, elegant appearance
Panel size / configuration - Up to 2.5 m width × 3.0 m height per sash; 2 to 6 panels; corner, flush stacking, pocket options
Glazing / thickness - Supports double glazing units up to ~30 mm (with optional acoustic / solar control glass)
U-value / thermal performanceFrom around 1.3 W/m²K (depending on glass spec)
Acoustic performance - Up to ~41 dB noise reduction in premium glazing configurations
Max sash weight - ~320 kg per panel (depending on build)
Weather / air / wind rating - High performance — class 4 air permeability, class 7A water tightness, C5 wind resistance in tested configurations
Finish & colour options - Wide RAL palette, dual colour internal/external, anodised or textured finishes
Security - Multi-point locks, bonded construction, concealed hardware options
Benefits & Ideal Applications
- Maximised glazing, minimal frame — the 20 mm interlock lets light flood interiors while maintaining structure
- Contemporary & versatile design — works in flush stacking, open corner, or pocket configurations
- Thermal & acoustic comfort — maintains insulation and reduces external noise
- Flexible for new build or retrofit — can be used in stand-alone or integrated into existing masonry
- Smooth operation — reinforced rollers and tracks enable effortless sliding, even on large panels
- Low maintenance & durable — aluminium construction with quality coatings resists weather and aging
Design, Supply & Installation Approach - full national reach
- Site survey & technical assessment — measuring apertures, access, structure, drainage
- Specification & layout design — optimizing number of panels, track options (2, 3, quad tracks), interlock arrangement
- Bespoke manufacture — precision fabrication to your dimensions and finish preferences
- Professional installation — ensuring proper drainage, sealing, alignment, integration with floors/walls
- Aftercare & warranty — support, maintenance guidance, performance guarantees
We coordinate with your builder / architect to ensure clean floor transitions, threshold integration, and alignment with adjacent glazing.
GS20 VS COR VISION SLIDER - WHICH ONE SHOULD YOU USE ON YOUR PROJECT?
The GS20 and Cortizo COR Vision are both ultra-slim aluminium sliding door systems with a 20mm interlock, created to maximise glass and provide a contemporary minimalist appearance, but they differ in positioning and capability. T
he GS20 is a high-spec slimline slider ideal for most premium residential projects because it offers excellent sightlines, strong weather performance and good thermal efficiency at a more accessible price point.
Cortizo COR Vision, meanwhile, is a more architectural-grade system designed for larger or more complex installations where flush thresholds, recessed frames, corner sliders without posts or pocket sliding arrangements are required.
In standard form, both systems are similar in performance – typically supporting sashes up to around 2.5m x 3m, weights up to 320kg per panel and U-values around 1.3 W/m²K – so for most homes the end result in look and feel will appear almost identical.
The main advantage of COR Vision comes when scaling to very large expanses of glass or when integrating into structural openings: its “COR Vision Plus” upgrade allows for thicker glazing, heavier sash weights and even motorised operation, which suits high-end projects and architectural extensions. GS20 still supports multiple panels, corner and large-format layouts, but it is generally aimed at the residential market rather than extreme-span glazing.
In terms of cost, GS20 tends to be more cost-effective, while COR Vision commands a premium for its scalability and recessed-frame detailing. Both offer extensive RAL colour options and dual colour finishes, although Cortizo also offers more specialised architectural surface finishes.
In summary, GS20 is the ideal choice for most homes wanting a slim, modern sliding door system with beautiful minimal sightlines, and COR Vision is the better choice when a project requires the very highest levels of structural flexibility, extreme panel size or fully flush, near frameless architectural detailing.
GS20 Sliding Door — Supplied & Installed Across the UK
We supply and install the GS20 Sliding Door system by Cortizo nationwide. Whether you’re opening up a full elevation, upgrading patio doors or building a new extension, our installation network covers all major UK regions with professional service and full support.
South & South East
GS20 Sliding Door London, Kent, Surrey, Sussex, Hampshire, Southampton, Home Counties and Essex.
From inner-city London flats to West Sussex coastal homes, our South & South East team delivers full design, survey and installation for the GS20 system in your area.
South West & West
GS20 Sliding Door Devon, Bristol and Gloucester.
Perfect for modern builds, barn-conversions or large countryside homes, we bring the GS20 sliding door system with premium finishes and expert installation across the South & West.
Midlands & Central
GS20 Sliding Door Birmingham, The Midlands, Northamptonshire, Nottinghamshire, Leicestershire, Derbyshire and Lincolnshire.
Our Midlands region teams provide efficient lead-times, detailed surveys and professional fitting of the GS20 door system for both residential and commercial projects.
North West
GS20 Sliding Door Greater Manchester, Manchester, Lancashire, Liverpool, Cheshire, Cumbria and Carlisle.
From city-centre apartments to rural homes in Cumbria, we supply, install and service the GS20 sliding door with local knowledge and full after-care.
Yorkshire & North East
GS20 Sliding Door Yorkshire, Newcastle and the North East.
Renovating a Yorkshire home or working on a development in the North East? We install the GS20 system across the region with all specification, colour and hardware choices included.
GS20 SLIDING DOORS | FULL PRODUCT REVIEW
GS20 SLIDING DOORS | ULTRA-SLIM ALUMINIUM BY FENESTRATION NETWORK
Discover GS20 sliding doors – ultra-slim 20mm frames, smooth operation, and stunning design. A premium aluminium slider for modern UK homes.
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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:
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