Vitrage

Vitrage is the architectural term referring to the glass element used to fill window, door, and façade openings. In its broad sense, it designates the glazing portion of a building envelope—the panes of glass and their assembly within a frame or supporting structure. The term is especially common in French technical language and is used in English to describe glazing systems as well.

Glazing systems range from single glazing, which uses one pane of glass, to more advanced configurations such as double or triple glazing. Insulating glazing units (IGUs) consist of two or more glass panes separated by a spacer and sealed around the edges, often with an inert gas fill (such as argon) to improve thermal performance. Other important variants include laminated glass, which bonds glass sheets with an interlayer for safety and acoustic performance, and tempered glass, which is treated to enhance strength and safety. Coatings, such as low-emissivity (low-E) or reflective films, modify optical and thermal properties by reducing heat transfer and controlling daylight.

Performance characteristics of vitrage are measured by metrics such as heat transfer (U-value), solar gain (g-value or SHGC), visible light transmission, and acoustic insulation. The choice of glass and coatings depends on climate, daylighting goals, safety requirements, and energy targets. Safety glazing is often required in certain locations and configurations, typically achieved through tempering or laminating.

Manufacture and installation involve fabricating glass panes to fit frames, applying edge finishing, and assembling spacers, seals, and gaskets in IGUs or monolithic panes. Standards and regulations governing vitrage vary by region, but commonly address performance, safety, and durability criteria for building glazing systems.