Horizontal Sliding

Engineered for flexibility across a wide range of commercial window configurations, delivering slim sightlines, smooth operation, and reliable long-term performance

Horizontal Sliding

Our horizontal sliding system is engineered for flexibility across a wide range of commercial window configurations, delivering slim sightlines, smooth operation, and reliable long-term performance.

Configured with 2, 3, 4, or 5 independently sliding sashes, the system provides generous access for cleaning and maintenance, and controlled ventilation, while maintaining a discreet appearance.

For larger or more demanding openings, our Enhanced range offers the same core benefits, with heavy-duty framing and self-supporting panes that ensure stability and strength across larger glass units.

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Horizontal Sliding Two Panel

Horizontal Sliding Three Panel

Horizontal Sliding Four Panel

Horizontal Sliding Five Panel

Technical Performance Data

Full panel sizing, acoustic and thermal performance data for the Horizontal Sliding range. Available in 2, 3, 4, and 5-panel configurations - all panel counts share the same maximum dimensions.

Up to 49 dB Noise Reduction (Rw)
1.5 W/m²K Best U-value
4,934mm Max Frame Width
6 Glass Types Available

Values are Rw (dB) measured to BS EN ISO 717-1. All tests performed with a 200mm air gap (glass-to-glass) and a 6mm single-glazed toughened primary window in a hardwood frame. Deduct 1 dB for a 150mm air gap; deduct 1–4 dB for a 100mm air gap.

Secondary GlassRw (dB)
Weighted		Rw+C (dB)
Traffic weighted		Rw+Ctr (dB)
Low-freq weighted
4mm Toughened474543
6mm Toughened494744
6.4mm Laminate494845
6.8mm Laminate494845
8mm Toughened494845
8.8mm Laminate494945
10.8mm Laminate494946

Rw data extrapolated from physical tests at Element High Wycombe (23/06/22 & 12/07/22). Test configuration: 1,200 × 1,200mm unit, 200mm air gap, 6.87mm standard laminate secondary glass, 6mm single-glazed toughened primary in a hardwood frame.

Data extrapolated from physical testing at Element High Wycombe (23/06/22 and 12/07/22).

Download Performance Data Sheet: GSG-DS002 Rev A — Acoustic

U-values shown are combined whole-window system Uw values (primary window + air gap + secondary glazing), calculated to BS EN ISO 10077-1:2017 and BS EN ISO 10077-2:2017 with a 50mm air gap. These are not the centre-of-glass Ug values of the secondary unit alone. Values marked * are indicative figures calculated internally by Granada Glazing Ltd. and have not been externally verified — all other values are from calculations by Windata Ltd.

Hardwood primary - 4mm float glass, 60mm hardwood frame, Uw = 4.7 W/m²K | Steel primary - 3mm float, steel Crittall frame, Uw = 6.0 W/m²K
Secondary GlassHardwood Primary
U W/(m²K)		Steel Primary
U W/(m²K)
4mm K Glass1.51.59*
6mm Toughened1.63*1.76*
4mm Toughened1.64*1.77*
6.4mm Laminate1.64*1.77*
6.8mm Laminate1.63*1.76*
6mm K Glass1.51.58*

* Indicative values calculated internally by Granada Glazing Ltd. - not externally verified. All other values from Windata Ltd. calculations per BS EN ISO 10077-1:2017 & BS EN ISO 10077-2:2017.

Download Performance Data Sheet: GSG-DS003 Rev B — Thermal

All dimensions in mm. Sizes are for guidance only and depend on glass type, subframe, and installation method. Contact us to discuss units outside the listed parameters.

Glass TypeMin WidthMin HeightMax WidthMax HeightAspect Ratio
(W:H)		Max Panel
Weight
4mm Toughened250mm300mm2,450mm2,700mmHS2 1:3.5 / HS3 2:3.5 / HS4 3:3.5 / HS5 4:3.580 kg per panel
6mm Toughened250mm300mm2,450mm2,700mmHS2 1:3.5 / HS3 2:3.5 / HS4 3:3.5 / HS5 4:3.580 kg per panel
6.4mm Laminate250mm300mm2,450mm2,700mmHS2 1:3.5 / HS3 2:3.5 / HS4 3:3.5 / HS5 4:3.580 kg per panel
6.8mm Laminate250mm300mm2,450mm2,700mmHS2 1:3.5 / HS3 2:3.5 / HS4 3:3.5 / HS5 4:3.580 kg per panel
8.8mm Laminate250mm300mm2,450mm2,700mmHS2 1:3.5 / HS3 2:3.5 / HS4 3:3.5 / HS5 4:3.580 kg per panel
10.8mm Laminate250mm300mm2,450mm2,700mmHS2 1:3.5 / HS3 2:3.5 / HS4 3:3.5 / HS5 4:3.580 kg per panel
Product RangeGlass OptionsMaximum Window Dimensions by Window Type HS5Installation Options
Width (mm)Height (mm)Area (m²)Face Fix
Through Timber		Reveal
Fix Through Frame		Reveal
Fix Through Timber		Optional Deep
Reveal Fix Through Timber		BevelsSpecials
Classic4.0mm tough493419687.5TIM-43x16TIM-43x16TIM-62x16TIM-70x16TIM-62x50TIM-90x90
Enhanced6.0mm tough4934206810.2TIM-43x16TIM-43x16TIM-62x16TIM-70x16TIM-62x50TIM-90x90
Enhanced6.4mm Laminate4934206810.2TIM-43x16TIM-43x16TIM-62x16TIM-70x16TIM-62x50TIM-90x90
Enhanced6.8mm Laminate4934206810.2TIM-43x16TIM-43x16TIM-62x16TIM-70x16TIM-62x50TIM-90x90
Enhanced8.8mm Laminate4934276813.7TIM-43x16TIM-43x16TIM-62x16TIM-70x16TIM-62x50TIM-90x90
Enhanced10.8mm Laminate4934276813.7TIM-43x16TIM-43x16TIM-62x16TIM-70x16TIM-62x50TIM-90x90

Our Sheffield-based manufacturing base is home to our very own painting plant, allowing you to choose from a comprehensive palette of more than 200 powder-coated RAL colours to achieve a precise match with your Granada secondary glazing system. Suitable for new developments, heritage buildings, and complex commercial environments, our finishes are specified to meet the requirements of each project.

Stocked colours available from short lead times

White
RAL 9003
Cream
RAL 9001
Van Dyke Brown
BS 08 B29
Anthracite Grey
RAL 7016
Black
RAL 9005
+200 RAL
custom colours

Frame Dimensions

All sizes in mm. Max frame width 4,934mm (HS5 inc. 16mm timber). Max panel height 2,768mm.

Frame and panel tolerances: ±1.5mm

Glass Thickness Tolerances

  • Toughened: ±0.2mm
  • Laminated: ±0.4mm
  • Laminate interlayer: ±0.1mm

Acoustic Test Conditions

All windows tested at 1,200 × 1,200mm with a 200mm air gap and 6.87mm standard laminate, against a wood-framed primary with 6mm single-glazed toughened glass.

Max Delivery

Maximum delivery size: 2,100 × 4,400mm

Product Case Studies

St John's University, York

St John's University, York

St John University's Creative Centre required a discreet, high-performance acoustic solution to contain internal noise and prevent disturbance to nearby residents. Our white satin powder-coated horizontal sliding units with 6.4mm acoustic laminated glass provide the modern aesthetic needed while delivering exceptional noise reduction and offering an ideal solution to reduce heat loss.

Read full case study
Eden Locke Hotel, Edinburgh

Eden Locke Hotel, Edinburgh

Situated on George Street, one of Edinburgh's busiest roads, Eden Locke needed a solid solution to reduce noise intrusion. Granada specified horizontal sliding units with 10.8mm high-performance acoustic panes of glass to effectively minimise external noise, while remaining sympathetic to the building's heritage and complying with listed building regulations for windows.

Read full case study
What is secondary glazing?
Secondary glazing is a discreet internal window system installed to the inside of an existing window. Available in a range of styles to suit almost any window type, it significantly reduces external noise and improves thermal performance without altering the building's original fabric.

Because secondary glazing is fully reversible and non-intrusive, it is well-suited for use in conservation areas and Grade I and Grade II listed buildings. All Granada systems are manufactured from durable aluminium and can be powder-coated in-house in over 200 RAL colours, allowing the glazing to blend seamlessly with its surroundings.

Secondary glazing is most often specified to address two key challenges: acoustic control and thermal efficiency. No other glazing solution can achieve comparable levels of noise reduction - up to 80%, equivalent to as much as 54dB. It also provides an added layer of security, acting as a secondary barrier should the primary window be compromised.

Designed to work with single-, double-, or triple-glazed timber or uPVC windows, Granada secondary glazing delivers long-term performance unmatched by alternative window systems.
Will secondary glazing work with double or triple-glazing?
Secondary glazing can be used alongside almost any window type. Traditionally specified to improve the thermal performance of single-glazed timber windows, advances in glazing technology and aluminium frame design have given secondary glazing a renewed and expanded role across both historic and modern buildings.

Its acoustic performance is unmatched by any other glazing solution, delivering significant reductions in noise transmission through single-, double-, and even triple-glazed windows. In high-noise environments, secondary glazing can reduce sound levels by up to 54dB, transforming disruptive external noise into a far quieter internal environment.

Granada secondary glazing is manufactured from durable, slimline aluminium profiles and can be powder-coated in-house in over 200 RAL colours, allowing each system to match the primary window perfectly.

Designed to enhance both thermal and acoustic performance, Granada's secondary glazing combines discreet appearance with long-term durability, delivering reliable performance that stands the test of time.
What materials are used for the frames?
As a leading name in the glazing industry, Granada ensures that every secondary glazing system combines high performance with a refined, discreet appearance. Our approach is simple: use the finest materials and manufacture to the highest possible standards.

All aluminium frames are produced in-house, using precision machinery to cut, powder coat, arch, and fabricate each unit under one roof. Advanced CNC technology ensures every frame is built accurately as a sealed unit, ready to deliver consistent performance.

Our expertise and commitment to quality set us apart. Unlike some competitors who reduce aluminium content to cut costs, compromising strength, stability, and acoustic or thermal efficiency, Granada maintains robust frame construction, ensuring safe, long-lasting, and high-performing glazing solutions.

Backed by a dedicated team of product developers, every system is designed, tested, and refined using innovative materials and techniques. This meticulous approach ensures that every product leaving our facility meets our high standards.
How to achieve the best thermal performance?
Draughty windows can make a room feel uncomfortable and increase energy costs by allowing heat to escape. Granada secondary glazing, available with 4mm, 6mm, 6.4mm, or 8.8mm toughened Low E glass, can reduce heat loss by up to 65% while effectively preventing draughts. Low-E glass is specially hard-coated to reflect heat into the room, improving comfort and efficiency.

For optimum performance, secondary glazing is best face-fixed to the interior of the primary window, with an air cavity no greater than 80mm. It enhances thermal efficiency when installed alongside single, double, or triple-glazed timber or uPVC windows.

Granada units can be supplied with or without a hardwood subframe. We recommend a hardwood subframe as it acts as a thermal barrier, preventing the aluminium frame and glass from cooling due to the temperature of the surrounding building fabric.

Our team is on hand to advise on the most suitable glass type, product, and installation method to deliver the best results for your building and requirements.
Can secondary glazing be installed within conservation areas and Grade I and Grade II listed buildings?
Secondary glazing is an ideal solution for conservation areas and Grade I and II listed buildings. Its discreet design enhances both acoustic and thermal performance, making it a popular choice within the heritage sector.

Recommended by English Heritage, secondary glazing can be installed without altering the building's original fabric, preserving its character while improving comfort and efficiency.