Small glazing glossary,
to speak like a pro.

Refers to cut edges. This finish consists of slightly rounding the edges of the glass to make them less sharp.

Energy Absorption (EA)
The percentage of solar energy absorbed by the glazing on a glazed wall varies according to several factors. Once absorbed, the energy can be reflected back outwards or inwards, depending on the characteristics of the glazing, environmental conditions such as wind speed, and internal and external temperatures. These factors influence the rate at which this energy is re-emitted.

Argenture
The operation involves applying a thin metallic layer to the glass to give it reflective properties, creating a “mirror” effect. This technique makes it possible to control light reflection while maintaining the transparency of the glazing.

Argon
This is an inert, colourless and odourless substance that is used in insulating glass units to improve their thermal performance, by reducing heat transmission. Inserted between two panes of glass, it increases energy efficiency by limiting heat loss, thus better insulating the inside of a building from external conditions.

Technical Opinion (TA)
This is a technical opinion issued at the request of a manufacturer, for an innovative construction product or system. This document is issued after an in-depth examination of the dossier by the Centre Scientifique et Technique du Bâtiment (CSTB), validating the conformity and performance of the product in the construction context.

A waterproofing barrier is a product, often butyl-based, used to seal the space between the panes of insulating glass against water vapour and gases. It plays a crucial role in preventing condensation and maintaining the thermal performance of the glazing.

Energy balance

The energy balance is the difference between heat input (such as solar heat or heating systems) and heat output (heat loss through walls, windows, etc.). It is used to determine the energy efficiency of a building in terms of heating and cooling. A positive energy balance means that heat gains outweigh heat losses, while a negative balance indicates significant heat losses.

Pink noise (RA)

Rw + C = RA: Pink Noise. In acoustics, pink noise simulates noise emitted in a building and is often used to represent noise generated by air traffic

Road noise (RA,tr)

Rw + Ctr = RA,tr : Noise Route.

Road noise simulates the noise generated by road traffic, particularly urban traffic. These sounds are deeper.

Polyvinyl butyral (PB)

The PB (polyvinyl butyral) is a synthetic film inserted between two panes of glass to form laminated glazing. It improves impact resistance, prevents splinters from scattering in the event of breakage and offers acoustic insulation as well as a UV protection. Available in transparent, coloured or patterned versions, it combines safety and aesthetics.

Acoustic polyvinyl butyral (acoustic PB)

This is a plastic film specially designed to improve sound insulation in laminated glass. As well as holding the glass components together, it improves the acoustic performance of the glazing by reducing noise transmission. It is particularly used in applications requiring a high level of protection against noise.

This certification guarantees the quality of insulating glass units according to very specific criteria. It ensures our customers that the products we supply meet performance and durability standards. Our 4 centres are CEKAL certified (link to our certifications and commitments page).

Scientific and technical centre for the building industry (STCBI)

CSTB is responsible for examining applications for Technical Approvals and Experimental Technical Approvals. It assesses and validates innovative construction products and systems, guaranteeing their compliance with standards and performance requirements. It plays an essential role in the innovation and regulation of materials and technologies used in the building sector.

Thermal shock

This is a significant difference in temperature within a pane, between two close areas, which can cause cracks or breakage. This phenomenon, known as ‘thermal shock breakage’, is reduced by the use of toughened glass, which is more resistant to rapid temperature variations.

Falling people or glass (DTU 39)

Vertical glazing located less than 1 m from a parking area must withstand impact tests simulating a falling person. In addition, any glazing inclined more than 5° from the vertical must meet the safety requirements for falling glass elements. Thickness and size specifications are calculated according to criteria defined in DTU 39, taking into account various parameters such as region and altitude.

U-value (or Ug)

The U coefficient is the thermal transmittance coefficient, expressed in W/m².K and represents the quantity of heat in W that passes through one square metre of material for a temperature difference of 1 degree Kelvin between the two environments. The lower the U-value, the more insulating the material. Conventionally, the U-value is that calculated at the centre of the glass.

Unit that measures noise. Essential for acoustic glazing.

DTU39

(Unified Technical Document 39) is a French standard that governs the design and installation of glazing in buildings. In particular, it specifies safety requirements to prevent people or glass elements from falling, with criteria adapted to vertical walls and inclined glazing. Calculations take into account parameters such as region, altitude and roof characteristics.

These classifications relate to the performance of fire-resistant glazing :

• E (Flame arrester)

Ensures mechanical resistance and flame-tightness.

• EW (Limited radiation flame arrester)

Adds limitation of heat radiation through the glazing, while being flame-tight.

• EI (Firestop)

Combines mechanical strength, flame resistance and thermal insulation, preventing heat transmission.

Emissivity (∈)

Emissivity measures the ability of a material to release energy in the form of radiation. In double-glazing, a low-emissivity coating applied to the inside retains infrared energy while allowing visible light to pass through. This significantly reduces the emissivity of the glass surface, improving thermal performance and energy comfort.

EN

European standards.

ERP

The Evasafe glazing are composed of two laminated glasses with an interlayer of ethylene vinyl acetate (EVA), which becomes transparent after baking. This process ensures strong adhesion, to increase impact resistance and limit the risk of injury in the event of breakage. Used in architecture and safety, they are manufactured under vacuum and at high temperature to guarantee optimum quality.

Solar factor (FS or g)

The solar factor measures the total amount of solar heat that penetrates a room through the glazing. This heat can enter in two forms :

• directly by transmission of solar radiation

• indirectly by heat transfer of some of the energy absorbed by the glazing.

This factor is essential for assessing the energy efficiency of a pane, particularly in terms of thermal comfort.

Float

Flat glass

Heat Soak Test (HST)

The Heat Soak Test is an additional heat treatment applied after the glass has been tempered. It is designed to significantly reduce the risk of spontaneous breakage, often caused by the presence of nickel sulphide inclusions in the glass. thermally toughened glass. This process ensures greater glazing reliability and safety, particularly in applications where mechanical strength is crucial.

Acoustic attenuation index (R)

Measured in decibels (dB) in the laboratory, this index assesses the ability of a construction element (such as glazing) to attenuate airborne noise. The higher the index, the better the acoustic insulation.

Spacer

An element used in the manufacture of insulating glass units to separate the two layers of glass. It is used to maintain the gap between the panes while improving the thermal performance of the glazing.

Digital printing

This is a process that enables images, patterns or text to be transferred directly onto the surface of the glass using specialised digital printers. This technique offers great precision and enables glass to be customised with complex designs, while maintaining strength and durability to suit the environment.

Reinforced thermal insulation (ITR)

Enhanced Thermal Insulation is when insulating glass incorporates low-emissivity glass. Thanks to a special coating, this glass limits interior heat loss while allowing natural light to pass through, thereby improving the energy efficiency of buildings.

This is a matt finish applied to the edge of the glass.

JPP (Polished flat gasket)

This is a finish applied to the glazing to give a clean, crisp appearance, with no visible cracks between the panes of glass.

Designates lacquered decorative glass from AGC. This glass is available in a wide range of colours and offers good resistance to impact, heat and humidity, making it suitable for spaces such as kitchens and bathrooms.

Lacquering

Glass lacquering involves applying an opaque paint or lacquer coating to one side of the glass. This coating can be coloured or transparent, and improves the aesthetics, protection and functionality of the glass. Lacquering is used in a variety of fields, including decorative applications, partitions and façades, providing a smooth, resistant finish while allowing the colours and visual effects of the glass to be customised.

EPR (Extended Producer Responsibility) building refers to the obligation for producers of certain construction products to take responsibility for the recycling and management of their end-of-life waste. This regulation aims to reduce the environmental impact of materials used in construction by encouraging their recycling and reuse, in line with the principles of the circular economy.

Vacuum glazing is a type of insulating glass that uses an empty space between two panes of glass, almost completely eliminating air to minimise heat loss. This makes it possible to achieve very high thermal and acoustic insulation performance, surpassing that of traditional glazing. This type of glazing is particularly popular in energy-efficient buildings, where reducing heat loss is essential.

Low-emissivity coated glass

This type of glass has a metallic coating or mineral film that effectively reflects long infrared radiation, mainly emitted by heat sources. This helps to reduce heat loss while maintaining transparency close to that of conventional glass. Coated glass low-emission can be manufactured with soft or hard layers, depending on the type of treatment applied.

Solar control glass

This glass is designed to limit the entry of solar heat in a building while allowing good transmission of natural light. It often has specific layers or surface treatments that reflect or absorb some of the sun’s rays, reducing the need for air conditioning and improving energy efficiency.

Fire-resistant glass

This type of glass is laminated with special intermediate layers that swell when exposed to heat. This reaction creates an insulating barrier, offering protection against fire. Fire-resistant glass helps to limit the spread of flames and protect structures in the event of fire, while maintaining a degree of transparency.

Self-cleaning glass

This type of glass is coated with a photocatalytic and hydrophilic layer which, when exposed to UV rays, breaks down organic dirt. What’s more, thanks to its hydrophilic properties, water from rain or other sources of humidity helps to eliminate mineral particles. The result is glazing that stays clean for longer, reducing the frequency of cleaning.

Clear and extra-clear glass

Clear glass is made from conventional raw materials and has a slight green tint, especially in thicker glass.
Extra-clear glass, on the other hand, is free of this green tint thanks to the use of special raw materials, offering greater transparency for applications requiring maximum optical purity.

Frosted glass

This type of glass is modified to achieve a matt or translucent appearance, often using matting techniques such as acid or sandblasting. This allows light to be diffused while preserving privacy, making it an ideal choice for applications where complete transparency is not desired.

Laminated glass

This is a safety glass composed of several sheets of glass bonded together by polyvinyl butyral (PVB) films. This material offers high resistance to tearing, protects against UV rays and can also be used for decorative effects thanks to a range of colours. Le laminated glass is often used for its ability to stay in place even when broken, reducing the risk of injury.

Mirrored glass

This glass becomes reflective through the application of a metallic coating (usually silver and copper) followed by protective coatings. It can be made from clear or tinted glass, depending on the desired visual effect. This type of glass is often used in mirror, but also for decorative or architectural applications.

Sandblasted glass

Glass whose surface is rendered translucent by high-pressure sand blasting. This treatment gives it a matt appearance while retaining a certain opacity, allowing privacy to be preserved while allowing light to pass through. This type of glass is commonly used for partitions, shower enclosures and decorative elements.

Tempered glass

Glass that has undergone heat treatment to strengthen its resistance. This process involves heating the glass followed by rapid cooling, which creates internal stresses that make the glass stronger. If broken, it shatters into small, non-cutting pieces, reducing the risk of injury. It is commonly used in applications requiring increased safety, such as doors, windows and facades.

A spacer in an insulating glass unit with low thermal conductivity, which reduces heat loss at the edges of the unit. This improves the energy performance of the glazing, particularly in terms of thermal insulation and condensation.