Engineering Design Practice

Eckersley O’Callaghan


Doorline Glass and Metal

The Calhoun School, NYC

The Calhoun School is a co-educational, progressive independent school on NYC’s Upper West Side, serving students in preschool and kindergarten through 12th grade.


Architectural firm FXFOWLE expanded the entire buildings footprint and allowed for more natural light. AGNORA fabricated the entire glass facade including the corner units.

The project consisted of laminated glass units, with the largest up to 115″ in height. The wall cladding, located at the school’s entrance, consists of laminated, oversized glass units with green opacicoat on the back layer.

Learn more about the Calhoun School from FXFOWLE, here.

Laminated Glass

Laminated glass is a safety glazing material that holds together when shattered. Laminated glass may crack upon impact, but the glass fragments adhere to the protective interlayer rather than falling free and potentially causing injury. Typically laminated glass is constructed with two plies of glass permanently bonded together with polyvinyl butyral (PVB). Those plies can be annealed, heat strengthened or tempered. AGNORA can laminate up to 8 layers of glass and 100 mm – 4” thickness.

Laminated glass has been used since 1939 in automobile windshields. Its use in architectural projects started in the 1960s in applications where there is a possibility of human impact or where the glass could fall if shattered. Skylight glazing typically uses laminated glass. This is the best technology in hurricane-resistant construction; laminated glass is often used in exterior storefronts, curtain walls and windows.

The use of ionoplast interlayer (SentryGlass® IG) opens up a new era in structural glass design. Advanced interlayers offer design flexibility with options for translucency, colour, printed designs, etc.

Advantages of Laminated Glass

Safest glass available – retains fragments
Remains intact, transparent and functional even if broken – perfect for storefront
Provides safety with annealed glass – no roller wave distortion
Design freedom: colour, translucency, opaque, solar control
Burglar retardant
Bullet resistant when multi-layers of glass are used
Protection from flying debris in hurricane
Protection for bomb blast
Cuts 99% of Ultra-Violet light
Improves acoustic properties