As the ongoing construction of Taipei Performing Arts Center (TPAC) nears completion in Taiwan, we take a look at our collaborations with Dutch architecture studio OMA featuring a structurally robust “S” shape curved glass system.
 

These projects feature laminated annealed “S” shape curved glass with tight, or small, curvature radii - a particular glazing system developed with Pritzker Prize laureate Rem Koolhaas and the team at OMA which takes advantage of the geometric stiffness of curved glass to resist environmental structural loads.

Taipei Performing Arts Center, scheduled for completion later this year
 

TPAC designers faced a common challenge to glass design ambition; the structural response to building loads. Where the characteristic strength of annealed glass approaches its limit under specific project conditions, specifiers will turn to heat strengthened alternatives such as tempered/toughened glass, which has a higher material stiffness, and rule out the option of annealed glass.

In the case of curved glass, we can benefit from the unique characteristics of curved surfaces - the geometric stiffness can provide structural robustness that would otherwise prohibit use of annealed glazing.

In a system developed with OMA for the Casa da Música in Porto, Qatar National Library in Doha and TPAC, curvature profiles of tight radii in close proximity of one another provide such robustness, and offer an engineered solution to the use of annealed glass. Structurally, the same theory applies to the famous catenary arches of Catalan architect Antoni Gaudí (1852 - 1926).

Source: Structural Design in the Work of Gaudí

Qatar National Library, 2017

This principle extends to the support conditions, where the perimeter framing supporting each glass unit has been reduced from all four sides, to just two-side supported - along the top and bottom edges of the panel. Aesthetically, this means that vertical support members, or mullions as they are commonly referred to, do not interrupt the viewing experience of the onlooker.

The lack of vertical lines fosters visual continuity between the inside and outside environment of the building – an invitation to experience the building and surrounding urban space with the engineered transparency that only glass can offer.
 

Casa da Música, 2004
 

Taipei Performing Arts Center, 2019

As an advantage to thermal performance, fewer metallic framing members also reduce the ‘bridge’ between ambient outdoor conditions and the controlled internal environment. This bridge can be understood as a transfer of heat through a window, which is limited by the air cavity in insulated glass units, but compromised by metallic properties of the framing system, as metal conducts heat.
 

Eliminating framing reduces heat transfer, which in turn reduces the energy required to maintain the building’s thermal comfort systems.

This was particularly important for Qatar National Library, a building facing the challenge of the extreme temperature variations in Doha. Laminated curved glass with a Low-E selective coating was fabricated for this public building, a sustainable solution for a harsh environment.
 

Qatar National Library, 2017
 

Qatar National Library, 2017

Similarly, the Casa da Música features curved glass with a solar control film in between two layers of PVB to control infrared solar energy ingress while maintaining natural light transmission and the internal glass features high acoustic damping performance.

Casa da Música, 2004

Read more about the properties of the curved glass fabricated for these three iconic projects:

Annealed Curved Glass - Crisunid®
Energy Efficient Laminated Curved Glass - Crislan®

If you have more questions about these projects or our signature curved glass, please reach out.