The glass building envelope, which represents an essential component of a complex holistic climate concept, was based on the Schüco UCC 65 SG unitised façade for technical, economic and aesthetic reasons.
The 40-storey “Allianz Tower” office building is located in the Asian part of the metropolis of Istanbul, which is separated from the European side with the old town by the Bosphorus. Consequently, the New York architects FXFOWLE sought a cultural reference in the Ottoman geometric motifs of building.
At the same time, the concept strives for a modern synthesis of culture and climate. The sculptural, angular form of the building alludes to Cappadocia rock formations of the “Fairy Chimneys” in Anatolia, while a number of integrated gardens and the large “sky garden” at the top of the building anchor it in nature and the landscape.
Brilliant gold in colour and visible for miles around, the solar shading panels, which are arranged asymmetrically and in different densities across the building depending on the cardinal direction, are a design feature with a reference to regional building culture.
Differentiated sustainability assessment in accordance with LEED
The design for the Allianz Tower aspired to the highest LEED certification - Platinum - and took its bearings from the requirements of this differentiated and globally recognised rating system for green buildings in all relevant aspects.
Energy and water efficiency, the quality of the space and location, the use of sustainable materials from the region and numerous other assessment criteria were individually taken into account and ultimately led to an excellent overall evaluation for a high-rise building with 81 points out of a possible 110.
Project-specific individualised system façade
Technical, visual and economic requirements came together in the design for the rear-ventilated glass curtain wall. The option chosen was the custom unitised façade based on Schüco Façade UCC 65 SG - a powerful, flexible modular system for unitised façades.
In view of wind loads, weathertightness, security and other technical requirements, the means to move in a system environment which only contains components that have been tested by renowned test institutes proved to be a major advantage for the Allianz Tower over alternative special constructions.
Apart from the relatively ordinary parts of the façade, customised solutions are realised which will also ease the installion, as well.
For instance, at junction of the various inclined surfaces, special CNC milling pieces are used to combine the parts with a perfect tightness.
As further example, considering water drainage, special glazing gaskets are used where the inward inclination is more than 16 degrees.
Special solutions were also used for the double-skin safety glass compositions, which incorporate a low-e coating and a ceramic grid of dots in the glass composition due to the increased solar shading and the thermal insulation.
The Schüco custom unitised façade impressed the clients and architects from a visual and economic perspective too. A key aesthetic aspect was the flush-fitted external appearance of an all-glass façade in combination with narrow profile face widths of only 110 mm in the interior. Furthermore, the unitised construction ensured efficient fabrication and installation and
guarantees the easy replacement of individual glazing units if maintenance is required.
Project title: Allianz Tower, Istanbul (TR)
Client: Renaissance Development (USA)
Architect: FXFOWLE, New York (USA)
Façade consultant: Axis Facades, USA & Turkey
Fabricator: Aygün Alüminyum Sanayi ve Tic. A.Ş., Istanbul (TR)
Curtain walling for the tower: Custom unitised façade based on Schüco Façade UCC 65 SG