Secure support for the Estrel Tower element facade

Fastening expertise for Berlin’s new highlight

Estrel Tower Desktop
References
The Estrel Tower is currently being built in Berlin and will rise 176 metres above the city’s roofs once it has been completed. The 45-story tower becomes part of the construction ensemble of the Estrel Hotel. Anchor plates are used together with fischer FAZ II Plus bolt anchors and the fischer InnoLock FES insert rail to anchor the facade elements securely and permanently to the building envelope. 

The Estrel Tower in Berlin-Neukölln, designed by German-American architects Barkow Leibinger, will be the tallest high-rise building in Berlin at 176 metres after completion. 522 hotel rooms, suites, lofts and long-term apartments as well as a fitness and spa area are to be spread over 45 floors. In addition, the Estrel Tower will house office and coworking spaces, a gallery, a restaurant, a skybar and a flexible event space. Construction work began in 2021 July. The construction - a reinforced concrete structure with a single-shell glass facade - is expected to be completed by the end of 2025. From green roofs including photovoltaic systems to wildflower meadows, a new park along the Neuköllner Schifffahrtskanal and a bicycle parking garage to CO2-neutral district heating, high environmental and sustainability standards are implemented here. The Estrel Tower aims for LEED (Leadership in Energy and Environmental Design) certification with the highest “Platinum” award. 
Estrel Tower overview

Property profile of Estrel Towers Berlin

Architect
Architects Barkow Leibinger
Construction time (planned)
2021 July - end of 2026
Height:
176 m. Highest high-rise building in Berlin
Facade builder
FKN FACADE
Building scope
522 hotel rooms, suites, lofts and long-term apartments as well as a fitness and spa area on 45 floors

Spectacular view

The glass facade offers a spectacular view of the city. Introduced aluminium fins were specially adapted to the solar radiation on site to avoid heating up the rooms in summer, together with the solar protection glazing and closed facade parts. In terms of design, they add depth to the building view, supported by their diagonal orientation and their different distances to the building envelope. The facade elements are delivered to the construction site prefabricated at the factory. The classic structure consists of an aluminium support structure and a continuous glass pane as filling, in some cases also vertical opening wings, as well as integrated supply and exhaust air openings, the sealing system and connecting elements. Butt and saddle seals ensure air and water tightness - thus energy efficiency and protection against weather influences. The joints are properly bonded. This ensures that the building envelope is closed, tight and energy-efficient. Movements of the facade due to thermal expansion or wind loads are compensated. 

The facade builders commissioned by FKN FASSADEN install the elements floor by floor from bottom to top. It is crucial to secure people and heavy parts against falling. On average, the building envelope of a floor is completed with 64 elements per week. A total of 2,881 elements were installed.

Estrel Tower FAZ II Plus

Challenges: Wind and transport

In addition to occasional wind loads, facade builders face challenges during installation due to transport, among other things. The garment elements are 2.5 m wide and weigh approx. 800 kg, some of which weigh 1,000 kg, depending on the size. They are pulled upwards in a cage using electric winches. With a second system, the elements are pulled out of the basket and moved horizontally around the building to the installation location.

For heavy facade elements, secure fastening is crucial. Each element is anchored in concrete with two anchor plates together with two 173 mm long fish FAZ II Plus 16/50 R bolt anchors at least 85 mm deep. The “force bolts” absorb very high tensile and transverse forces. The anchors also score points with advantages such as quick and easy installation without drilling hole cleaning and high safety. Thanks to its service life of up to 120 years (confirmed by an external independent expert report), the FAZ II Plus guarantees a firm hold even after more than a century.

Estrel Tower Front

fischer products used

In the case of another fastening method, the fully hot-dip galvanised InnoLock FES RS-S fish insert rails are installed. The substructure brackets are fastened in front of the support on the front side with the hammer head screws FBC-S-225 in the size M16 x 80 mm. The InnoLock rails are already flush with the concrete support and embedded in the concrete. The facade builders attach the add-on parts to this using the corresponding hammerhead screws and nuts. To do this, turn the bolts approx. 90 degrees clockwise and then apply the specified torque. The facade elements are then flush-mounted into a recess in the anchor plates.

The wide, robust toothing of the fischer InnoLock rail and hammer head screw creates connections that can withstand the highest loads even in the longitudinal direction of the rail thanks to the proven positive fit. At the same time, the serrated connection and the low tightening torque facilitate and speed up safe assembly. The patented lip geometry (stepped rail lip) also enables high holding values for tensile, transverse and longitudinal loads. Thanks to an ingenious functional concept, the hammer head bolt remains securely connected to the anchor rail even under the highest loads.

The right fastening technology guarantees that the Estrel Tower, Berlin’s new landmark, will stay firmly in place beyond the city’s borders.
Estrel Tower fischer InnoLock insert rail
Permanently secure hold. Fischer InnoLock FES RS-S insert rails are used to secure the element facade to concrete supports. Associated FBC-S-225 hammer head screws engage positively with the serrated lips of the rail. The system guarantees maximum load capacity in all directions.
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