Façade Consultant: Eckersley O’Callaghan
Client: Beijing Municipal Commission of Planning and Natural Resources
Architect: Snøhetta
Façade Contractor: China Railway Construction Engineering Group
The Beijing City Library, a striking new addition to the city’s cultural landscape, sets a new benchmark in glass façade engineering with China’s tallest self-supporting glass façade. Designed by Snøhetta and engineered by Eckersley O’Callaghan, the building seamlessly integrates structural ingenuity with architectural ambition, ensuring that its transparent enclosure becomes a defining feature of the city’s skyline.
Image credits: Zhu Yumeng
At the heart of the library is an expansive terraced valley, with meandering walkways and tiered seating that create dynamic public spaces. A canopy of slender columns supports an overhanging roof punctuated by skylights, filtering natural light through a perforated ginkgo leaf-inspired structure. Encasing this volume is a remarkable 16m high, frameless glass façade, providing uninterrupted views of the interior and reinforcing the library’s openness and accessibility.
The façade’s engineering is a feat of precision and innovation. Initially conceived as a series of curved glass panels to enhance structural stiffness, the design evolved into a more efficient pleated configuration using flat insulating glass units (IGUs). This solution balanced architectural intent with cost-effectiveness and constructability, reducing the complexity of fabrication while maintaining structural integrity. The resulting façade consists of 15.8m tall panels, each approximately 2.5m wide, assembled with laminated glass and high-performance interlayers to achieve the necessary strength and transparency.
Image credits: Zhu Yumeng
One of the project’s most significant challenges was accommodating structural movements, particularly seismic activity. Due to Beijing’s high seismic risk, stringent design codes required provisions for lateral displacement of up to 120mm. The façade achieves this through a system of sliding connections at the top and bottom, incorporating stainless steel profiles within steel channels lined with PTFE bearings. This allows the IGUs to shift in response to roof and ground movements without damaging glass or structural silicone.
Thermal performance and solar control were key considerations in the façade’s design. The glazing achieves a U-value of 1.6 W/m²K, with a bespoke low-E coating providing a G-value of 0.24 to minimise solar heat gain. The deep roof overhangs further enhance passive shading, while the east and west façades incorporate terracotta panels that integrate seamlessly with the glass, reducing direct sunlight penetration while maintaining visual cohesion.
Image credits: Zhu Yumeng
Sustainability is embedded in the project’s design. The transition from curved to flat glass panels significantly reduced embodied carbon by lowering material waste and eliminating the additional energy-intensive process of curving glass. The pleated configuration optimises stiffness, allowing for a reduction in glass thickness without compromising structural performance. The façade played a critical role in the building’s achievement of a three-star rating under China’s Green Building Evaluation Label.
Beyond its technical prowess, the Beijing City Library stands as a symbol of modern civic architecture. Its transparent façade invites public engagement, blurring the boundaries between the built environment and its users. The collaborative efforts of Eckersley O’Callaghan, Snøhetta, and the structural and façade teams have resulted in a landmark that not only advances glass engineering but also redefines the role of libraries in the 21st century.
Image credits: Zhu Yumeng