Continental Europe - EN

Performance & Energy Efficiency

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Performance and energy efficiency

Understand how glass can influence a building's energy and acoustic performance

Applications of glass

Whether you need glass for facades, interiors, homes, or specific applications, we have a solution

Which glass is right

See how the right glass can help improve your quality of life and the beauty of your home

Understand glass

Learn more about glass and what you can do with it.

Design with glass

There’s almost no limit to what you can create with glass.

Build with glass

Glass is the ultimate building element, and can be tailored to each project.

Glass for your home

We’re helping glass inspire more homes than ever before.

BNL-BNP Paribas

Due to the clever structural glazing, the aesthetics are visually appealing, reflecting the building’s surroundings on all sides.

cube berlin

Architects 3XN have created deliberate geometric transformations that create a prismatic pattern of triangular surface reliefs.


Nobu Hotel Warsaw embraces the city’s charisma to create a genuinely unique, stunning structure in this cultural hub.

Our story

Just as we were in 1932, we're ready to meet the challenges of now and the future


Find out more about how glass can support sustainable design

Quality control

We strive for quality in everything we do

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Help and contact

Glass Analytics

Access our comprehensive suite of engineering and analytical tools

BIM objects

Download and use our standardized Guardian BIM content to create project specific BIM files

Seminars and online learning

For anyone who is interested in learning more about glass and its use

Performance and energy efficiency

Charlotte Plaza

Put it to work: performance glass and energy efficient glass

Glass can greatly influence energy use, light transmission, acoustics and facade strength. By understanding and applying each of these components, you can select the right glass for your project.

Glass Performance

Glass contributes to a building’s energy performance by affecting both natural light transmission and solar control. Performance glass is measured by the following: 


The glazing parameter that characterizes the heat transfer through the central part of the glazing, i.e. without edge effects, and expresses the steady-state density of heat transfer rate per temperature difference between the environmental temperatures on each side. Temperature differential according to standard conditions: delta T=15K°. The lower the value, the greater is the insulating value.


Solar factor

Describes total solar energy admitted through glazing. A lower number = less solar energy passing through the glazing into the interior.

Solar factor

Light transmission

Measures the percentage of visible light (in the wavelength range of 380 nm to 780 nm) that passes through glazing. A higher number = more natural light in interior spaces.

Light transmission


The selectivity is the light transmission divided by the solar factor. A higher number = brighter spaces relative to solar control performance.


Building Energy Efficiency

Glass can impact light transmission and solar heat to improve the comfort of occupants and help the HVAC system operate at maximum efficiency. 

High-performance glass with a high selectivity can enable buildings in warmer climates to enjoy the benefits of natural light without intense interior temperatures, or the need to block the light with shades. Meanwhile, buildings in cooler climates can benefit from passive heating offered by glazing with a high solar factor.

Glass coatings with a lower U-Value have higher insulating properties, helping to keep the interior temperature consistent regardless of the outside climate. 

A wide variety of architectural glazing products are available to facilitate harmony between aesthetics and energy efficiency. 


We are surrounded by sound. Unfortunately, what many might consider pleasant, such as birds singing or laughter, is unfortunately frequently drowned out by less welcome noise. According to the World Health Organization, excessive noise seriously harms us. It can disturb sleep, cause cardiovascular and psychophysiological effects and reduce performance.


Sound is transmitted through glass

The molecules compress against each other and spread that compression as a wave. Noise can be reflected or absorbed by glass to varying degrees, depending on the combination of glass thickness and interlayers.

 Sound is transmitted through glass


Performance glass can provide strength while still offering transparency and beauty. This video illustrates the strength variations of different kinds of glass.  

All architectural glass, in its original state, is annealed. Yet further load resistance is attainable by applying heat treatment. This involves carefully heating the glass, and then rapidly cooling its surfaces to induce permanent compression. It’s important to note that the glass must be cut and fabricated before the process. There are two kinds of heat-treated glass:

  • Tempered glass is approximately 4 x stronger than annealed (standard) glass. When broken, it is designed to break into small pieces with comparatively dull edges.  Tempered glass can correspondingly qualify as safety glazing. 
  • Heat-strengthened glass is approximately 2 x stronger than annealed glass. When broken, its shards are more conductive to retention within the glazing panel frame than are those of fully tempered glass.