Main Façade Technology
Allianz Tower

The vertical curve which covers the 6 floors (global curve) is led by a curvature within the single plane (local curve).

The High Performance TGU (light transmission 56% - solar factor 33% - external light reflection 17%, Ug= 0.7 W/m2K) is curved with a radius of 86m, equivalent to an arrow on the arc of 22mm in the 3900mm height of the surface, by a cold bending process (mechanical induced deflection on the flat plate, without the use of heating furnaces).

Allianz Tower

The natural bending glass result (directly processed in our factory) allows the achievement of a flat bent glazing, free from local deformation or visible distortions, with a further manufacturing advantage of lower costs.

The development of the bending process has required a series of laboratory tests:

  • IFT Rosenheim (Austria): TGU permeability tests in pressure and temperature differences,
  • DC laboratory (Belgium): adhesion and tension stress test,
  • Istituto Giordano (Italy): mechanical and weather tightness façade test,
  • Focchi spa (Italy): load-deformation test, in order to validate the induced tension state in structural silicone joints, in butyl junctions and in the differential slide of the glass slabs caused by the curvature induced by the curved template.
Arata Isozaki
Arata Isozaki
Arata Isozaki si laurea presso l'Università di Tokyo nel 1954 e studia con Kenzo Tange. Nel 1963 fonda Arata Isozaki Atelier, oggi Arata Isozaki & Associates. Membro della giuria del Pritzker Prize 1979-1984, Isozaki ha ricevuto riconoscimenti internazionali per le sue opere che sono state costruite in tutto il mondo. Tra i suoi progetti più importanti sono: il Museo d'Arte Moderna di Gunma (1978), il Museum of Contemporary Art di Los Angeles (1986), il Soho Guggenheim Museum di New York (1992), la Kyoto Concert Hall (1995), e l’Olympic Sports Hall di Torino (2002).
Andrea Maffei
Andrea Maffei
It’s 1997 when Andrea Maffei moves in Tokyo to begin its collaboration with Arata Isozaki, managing the Italian projects of the practice. In 2005 Maffei established the “Andrea Maffei Architects” practice, based in Brera. In 2006 he supervised the projects in Turin, such as the Palahockey, built for Winter Olympics and now called Palaisozaki, the Olympic pool and the Piazza d’Armi park. The architect was also in charge of the Allianz Isozaki Tower in CityLife, the former area of the fair in Milan. Furthermore, beside his professional work, he edits books and articles for several architectural magazines.
Allianz Tower

Allianz Tower

Amazes for its lightness and its technological content: a glass architecture that makes the city brightener, reflected on its façades.

Project Specs

  • Location: Milan
  • Contractor: Colombo Costruzioni
  • Client: CityLife Spa
  • Year of completion: 2015
  • 14 different façade systems
  • Fifty-floor, 209-metre-tall
  • Ph. Piermario Ruggeri


Allianz Tower


The building appears simple using exacting standards to achieve a slender shape, however it is actually composed of 14 different façade systems, which are connected to each other in a complex manner.

Main Façade

The main architectural envelope is essentially clad with a Triple Glazed Unit (TGU), which develops the theme of a “curve within the curve”. Even so simple and sober geometry is characterized by an intrinsic complexity of shape and connections among the different façades, which combine in the 4 vertices of the building rectangular plan.


A long design phase: about 35.000 hours and integrated engineering: about 50.000 hours has led to the functional connection of all components.

Designed by

Arata Isozaki Architects
Andrea Maffei Architect

Live Project

In the aspiration of maximum verticality and tension towards the sky, it was a limit to choose a complete shape and concluded at a certain height.

We preferred to apply the concept of a modular system that can be repeated in an infinite way.

The module we decided is composed by six office floors with a long thin plan of 24x61.5m. The choice of these proportions is finalised to make the whole volume thinner to emphasize the verticality and makes it structurally provocative, due to the slender shape so high.

The facade of the module is composed by a Triple Glass Unit (TGU) slightly curved to outside. The vertical succession of rounded forms create a feeling of slight vibration of the volume of the building as it rises upward. Elevations of the short sides are fully glazed and show the mechanical series of panoramic lifts going up and down to the various floors of the building.

Other Façade Systems


The repeated module every 6 floors incorporates a façade panel obtained by inserting extruded aluminum louvres, which emphasize the curve shrinkage. Both the units on the edges are completely cantilevered outside the building envelope and they are fixed to an overhanging beam, which is fully anchored beyond the concrete floors. This portion of façade essentially ornamental, has no weather tightness sealing function, but is completely overhanging and with a “C” shaped unit, due to the lack of the terminal mullion.

Panoramic lift cores

The panoramic lift cores, FC3-8, consist of a structural façade with double laminated low-iron toughened glazing.
A high transparency effect, avoiding the grid subdivision emphasis, is achieved by using low-iron glazing, polymeric gaskets and grey structural silicone, together with thin structural aluminium and steel profiles.

Ventilated façade

The ventilated façade in between emphasises the tower prominence through a horizontal pattern. An extruded aluminium blade of 200mm shaped and 5.4m long is laid up to a height of over 202m height. The technical floors set at level 24 and 50 feature a structural unitised façade, incorporating laminated enameled RAL 7035 glazed fins sequence of 300mm. The 5m fins permit to conceal the mechanical air conditioning plants.

Ground floor

The double height ground floor has been designed using SetryGlas® low-iron laminated glazed fins, 1,5m modules by 8,4m high. Reduced dimension aluminium mullions and transoms allows the maximum glazed transparency, achieving at the same time the specified weather tightness and structural integrity. External structural low-iron laminated SetryGlas® fins sequence integrate with the projecting ceiling, aligned with the overhanging face of glass of the second floor.