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XXL - Overlength Glass

New aesthetics with XXL glass panes

Producing and installing XXL glass panels, up to 18 metres in length, is technically and logistically unproblematic nowadays - and opens up entirely new creative possibilities.

Design and use

The use of façades with large areas of glass is a central theme in contemporary architecture. Glass panes in XXL format support this design goal with particular effectiveness. They help to shape the spatial experience inside the building as well as the external architectural character: A glass façade that uses oversized formats is very striking as well as transparent. The structural limitations appear to disappear and the rooms within the building are flooded with daylight.

XXL glass panes are recommended wherever the goal is to achieve open, airy aesthetics and a smooth transition between interior and exterior. The spectrum of applications in construction where the glass panes can be used is extensive and can include:

The technical possibilities now available make the range of application areas even wider - and their realisation easier. Design using glass panels longer than 6 metres is becoming the standard for more and more clients and architects.

Overlengths have their own tradition in architecture: here the UN building in Geneva from 1971 with 13-metre-high windows.

Overlengths have their own tradition in architecture: here the UN building in Geneva from 1971 with 13-metre-high windows.

Making use of all common glass types and processing techniques

Façades with oversized glass can be created using all common types of float glass and toughened coatings, thus covering a large part of the spectrum of glass processing.

Up to 18m and everything in between

Compared with the previous 6m standard, XXL glass panels with formats up to 18m x 3.21m increase the geometric freedom of glass façades threefold. Having significantly fewer glass panels for the same surface area allows for more discreet fastening systems as well as a higher level of clarity in the façade flow.

Designs with extra long panels means the building structure no longer has to adapt to the glass; floor heights and centre distances simply follow the architectural concept.

  • Uncoated basic glass
  • Coated heat and solar control glass
  • Processed glass, such as insulating, safety or design glass

Uncoated basic glass


With its low iron oxide content, this glass sets new standards when it comes to the look and aesthetics of float glass. Especially for applications involving thicker glass, SGG PLANICLEAR is very popular thanks to the fact that it lets in more daylight, is more colour neutral and absorbs less light.

Available in thicknesses of 8, 10, 12 and 15 mm.


The basic glass is extremely transparent due to its extremely low iron oxide content and has very little colour of its own. These properties allow the best possible neutrality, even with large and multi-layered glass structures, with natural illumination and undistorted reproduction of colours and contrasts.

Available in thicknesses of 8, 10, 12 and 15 mm.

Coated glass

SGG COOL-LITE® SKN II solar control coating

Highly transparent solar control coating with undistorted colour and a particularly natural lighting effect. The perfectly coordinated combination of superb solar control, high light transmission and excellent heat insulation ensures an ideal indoor climate in every season. Highly neutral transparency in both directions means it is also suitable for listed buildings. The layers of the SGG COOL-LITE SKN II family can be toughened.

Available in thicknesses of 8, 10 and 12 mm.

SGG COOL-LITE® XTREME II solar control coating

Highly efficient solar control coatings with a selectivity greater than 2 and U values up to 0.4 W / (m²K) in triple-glazed panels. Its high selectivity combines excellent light transmission with a low overall emissivity and creates an extremely bright atmosphere inside the room without overheating. The layers of the SGG COOL-LITE® XTREME II family are toughened, which increases both the mechanical and the thermal resistance.

Available in thicknesses of 8, 10 and 12mm.

Processed glass

XXL glass can be processed, assembled and finished by specialised glass processing companies using all the common methods known from standard formats. With safety or design glass, planners have the entire range of functional and design options at their disposal.

Everything is possible with XXL glass:

  • Pre-cuts and edge processing with an arrissed, cut or a polished edge
  • Drilled holes in the glass
  • Curved glass
  • Tempered glass as toughened safety glass, also with heat-soak test
  • Annealed glass
  • Laminated safety glass
  • Fall-proof glazing
  • Design glass with laminated colour or decorative foils
  • Single or multi-coloured decorations in ceramic digital printing
  • Full surface enamelling

Simple planning with large glass panels

Oversized glass panes are just as easy to plan with as the more common formats seen today. This is true of design and structural requirements as well as to the use of familiar tools.

XXL panes are not different, just larger

Planners have the following at their disposal:

  • the tried-and-tested tools and consulting services for modern glass façades
  • all traditional constructions: mullion and transom façades, element façades, storey-high glazing or high gloss glass façades
  • the complete range of heat and solar control coatings, safety glass and acoustic glass structures
  • plus the whole spectrum of creative possibilities offered by glass finishing
  • experienced partners from all areas: Specialist planners, contractors, logisticians etc.

Tools and consulting services

Calumen III/ CalumenLive

Saint-Gobain Building Glass software calculates the photometric and physical radiation data of Saint-Gobain glass panes, regardless of format and size. In addition, the technical performance of the glass - thermal insulation, solar control, fall protection, acoustic control etc. - can be determined with both programmes regardless of the type of glass.

On-site support

A network of over 80 consultants around the world will help you realise your project. Saint-Gobain will advise you on the ideal choice of glass and the development of an efficient glass construction.

GlassPro/GlassPro Live

Saint-Gobain provides planners with realistic renderings from the GlassPro app and the rendering service GlassPro Live. With both, the renderings show the glass in different light conditions (sunny, cloudy) and their effect on the interior. This highly realistic representation of the planned façade facilitates communication with builders and approval authorities.

Advice on transport and logistics

When transporting, storing and installing XXL glass panels, planners and builders can rely on experienced partners. Saint-Gobain provides advice and support in cooperation with glass finishing and installation companies. The range is huge: Panels can be transported that are up to 18 metres in length and with weights of up to 7 tonnes.


XXL glass can be used in all common façade constructions:

  • Mullion and transom structures
  • Element façades fixed in storey ceilings
  • Structural glazing

Both horizontal and vertical installations are possible.

Aluminium or steel

For aluminium mullion transom façades, the maximum lengths, allowable loads and deflection of the transoms need to be matched to the larger weight of oversized glass panels. If necessary, the performance of the aluminium can be increased with steel reinforcements or secondary steel structures behind the glass façade.

Alternatively, planners can choose a façade system made entirely of steel. Especially when it comes to heavier glass weights, steel scores points with its slimmer profiles that lend the façade maximum elegance and visual lightness.

Full-height glass panels

The special charm of XXL glass is that glass divisions within one floor are avoided. The glass can extend for an entire storey without interruption from the floor to the ceiling. Secure attachment to the base and the ceiling is of particular importance here.

And when XXL glass is placed horizontally, it enables large rooms or even entire sides of buildings up to a width of 18m to have uninterrupted and completely seamless façades.

All-glass façade

Oversized glass, and the significantly reduced glass divisions, open up completely new dimensions when it comes to elegant glass façades. The uninterrupted transparency of frameless constructions is particularly striking.

All-glass façades without load-bearing frames and posts are made either by using point-fixed glazing or with bonded glass as a structural glazing façade. If required, the latter can be equipped with additional mechanical safety measures.

Energy efficiency

Modern insulating glass is so efficient that the glass surfaces usually have better thermal protection than their supporting and fastening systems. In energy terms, the larger glass surfaces in the overall construction relativise the importance of the less thermally insulated profiles and glass edges. The energy efficiency of the entire façade is thereby improved.

Planners can rely on the usual high energy and radiation qualities of XXL glass, depending on the coating and glass structure:

  • Double insulating glass with U values of 1.0 W / (m²K)
  • Triple insulating glass with U values of 0.7 W / (m²K)
  • Noble gas filled or air-filled spaces
  • Highly selective solar and thermal protection coatings
  • Insulating glass with a thermally improved edge bond (warm edge)

Specialist planners and contractors

To help plan using XXL glass, Saint-Gobain has a list of experienced planners companies at its disposal.

Please click here to view the list.