Berlin’s New Height Record
At 176 meters, the Estrel Tower will become the tallest building in the German capital – a new landmark that will leave a lasting mark on Berlin’s skyline.
Client
Estrel Tower Besitz GmbH & Co. KG
Location
Berlin
Markets
Connect with an expert
Alexander Mühl
Division Manager
A New Landmark for Berlin
Ekkehard Streletzki is the owner of the Estrel Hotel and the Estrel Congress Center on Sonnenallee in Berlin-Neukölln. With his latest project, he is aiming high: the new Estrel Tower will rise 176 meters into the Berlin skyline, making it the tallest high-rise in the city and Germany’s tallest hotel. Designed by Berlin-based architects Barkow Leibinger, the building is planned to achieve LEED® Gold (Leadership in Energy and Environmental Design) certification.
Combined Pile and Slab Foundation
For Berlin’s tallest high-rise, CDM Smith developed an innovative foundation concept: 52 large diameter drilled piles and a 3.60 m thick base slab ensure maximum structural stability.
Soil Investigation and Foundation Concept
CDM Smith has been involved in the project since 2016 and is responsible for the subsoil investigation, the subsoil assessment and the design of the foundation. After intensive variant investigation, the foundation concept was narrowly decided in favor of a combined pile and slab foundation to avoid major deformations.
Particularly Challenging Building Foundation
The subsoil investigations of the area were carried out with boreholes down to a depth of 60 m. A rarely explored layer of the Holstein Warm Period was found under the expected and well-known sands and glacial till at a depth of about 50 m. Due to its composition (organic soils, clays and silts with augers, fluvial sands and gravels), this layer had to be considered with regard to the settlement prognoses and the foundation planning.
The verification of the combined pile-slab foundation was carried out in combination and on the basis of a structural model created by the structural engineer and a geotechnical model created by CDM Smith (G-model, created with PLAXIS®). As a result, the planning is based on a combined pile and slab foundation with 52 large-diameter drilled piles (length: approx. 20 m, diameter: 1.80 m) and a 3.60 m thick base slab.
Due to the possible settlements on the surrounding buildings, we made a decision for a combined pile and slab foundation. This is rather unusual for Berlin's subsoil conditions.
Alexander Mühl, Division Manager
The Tower Rises in Height
In March 2025, the Estrel Tower celebrated its topping-out ceremony – a significant milestone for the project, attended by numerous guests from politics, business, and architecture. The hotel is set to open in 2026, offering a stunning view of the capital’s skyline from the Skybar’s outdoor terrace.
Client
Estrel Tower Besitz GmbH & Co. KG
Location
Berlin
Markets
Connect with an expert
Alexander Mühl
Division Manager
Project Figures
52
large diameter drilled piles
up to 60 m
deep drillings
