Shanghai Tower

Location: Shanghai,China
Design firm: Gensler
Typology: Mixed use
Years: 2008–2015
Status: Complete

Facade facts

Facade summary: A highly innovative double-skin curtain wall system featuring a circular cylindrical inner wall and a twisting, triangular-profile outer wall that rotates 120 degrees over its height.
Documented intention: The primary design goal of the twist was to minimize lateral wind loads, which significantly reduced the amount of structural steel required for the building's core and frame. The double-skin strategy was also intended to provide a high-performing thermal barrier,reducing heating and cooling demands.
Street relationship: At the ground level, the outer facade transitions into a massive glass podium enclosure that opens towards the surrounding plaza, anchoring the massive tower to the street scale.
Climate relationship: The double-skin cavity acts as an insulating blanket, mitigating Shanghai's hot summers and cold winters, while wind turbines are integrated into the facade near the top of the tower to generate on-site power.
Window pattern: Curved, continuous glass ribbons wrapping around the twisted and cylindrical profiles.
Glazing: Double-glazed IGUs for the inner wall;laminated monolithic/laminated glass for the outer wall.
Depth: The depth of the air cavity between the inner and outer skin varies significantly, spanning several meters to accommodate the sky gardens.
Rhythm: Continuous spiral rhythm defined by the 120-degree twist and gradual vertical taper.
Laminated low-iron glass: Laminated low-iron glass — Outer curtain wall panels — Highly transparent,smooth
Insulated Glass Units (IGUs): Insulated Glass Units (IGUs) — Inner curtain wall panels — Standard reflectivity
Structural steel: Structural steel — Cantilever trusses,ring girders,and suspension hangers — Painted/Coated
Suspended double-skin curtain wall: The outer skin is a suspended unitized glass system hung from structural steel trusses at mechanical zones.

Description

The building features two distinct glass envelopes. The inner facade is a conventional cylindrical unitized glass curtain wall enclosing the usable floor plates. The outer facade is a complex, twisting triangular shell that tapers as it rises. The outer envelope is supported by an intricate system of structural steel cantilevered trusses, ring girders, and high-strength tension cables, allowing it to hang suspended. This double-skin assembly creates nine stacked vertical atriums that act as thermal buffer zones, insulating the building and housing sky gardens. The 120-degree twist of the outer skin was optimized through wind-tunnel testing to reduce wind loads by 24 percent.

Visual analysis

Visually, the outer facade presents a fluid, seamless, and highly transparent glass skin. The structural steel supporting hangers and trusses are clearly visible behind the glass, emphasizing the structural lightness and complexity of the suspension system.