AQ1
New life at the Franz-Josefs-Bahnhof: In the joint working partnership of AQ-Arch with DMAA, we are transforming the terminus station and the office building above it under the name Francis from an impassable barrier in the centre of the district into a transparently permeable centrepiece of the new Althan Quartier.
The decisive factor in the decision to convert, i.e. to demolish, redevelop and add storeys, was the significant impact on the ecological balance of the project. This meant that considerable amounts of CO2 could be saved.
Details
Categories
Works, Gastronomy, Conversion
Status
In realisation
Start of construction
Spring 2022
»Preserving valuable building structures where possible is the order of the day – in most cases, it is more sustainable than building new.«
Josef Weichenberger
Details
Team
Friedrich Hähle (project manager), Robert Huebser, Maria Nardelli, Giacomo Rocco, Stefan Schubert, Mark Steinmetz, Joscha Viertauer
Built-up area
approx. 11.000 m²
Gross floor area
approx. 70.000 m²
Project joint venture with
Webcam
Project website
»For Francis, we are taking the open formulation of Karl Schwanzer’s building a step further. In this way, we are creating transparency and new places of identification for the district.«
Friedrich Hähle, project manager
From a split neighbourhood to casual transparency
With Francis and the Althan Quartier around Franz-Josefs-Bahnhof (Franz-Josef-Station), a new urban and connecting quarter is being established in Vienna’s ninth district.
New thoroughfares form a bridge between the Spittelau and Lichtental districts, which were long separated by the railway tracks of the terminus station and the previously inaccessible former Bank Austria building. The 2.4-hectare site of the Althan Quartier now serves as a central connecting element in the district. This transformation has achieved one of the main objectives of the project: improving the quality of life and enhancing the living experience for the neighbourhood.
Conversion or the beauty of changes
The project illustrates the potential for urban development and environmental benefits that lie in the transformation of existing buildings. Particularly in times of land and resource scarcity, the preservation and further development of valuable existing structures is worthwhile.
As a large proportion of the so-called grey emissions are bound up in the steel and concrete supporting structure, conversion in the case of Francis means enormous ecological benefits: instead of 27,595 tonnes of CO2 for demolition and new construction, the value for conversion is 8,970 tonnes of CO2 – a saving of 67 percent. According to the results of a study by sustainability expert, architect and civil engineer Werner Sobek, 122,480 tonnes of concrete and 10,944 tonnes of steel were saved, which is groundbreaking regarding the shortage of raw materials and climate change.
In addition, the quality of life of local residents was maintained during the renovation – an estimated 10,000 lorry journeys were avoided by not demolishing and rebuilding the existing. Necessary dismantling work, removal and recycling were carried out inside the building and in the underground loading yard, minimising dust, noise and construction site traffic.
Study and analysis of the existing building
The new design was preceded by an extensive reading and understanding of the existing building from the 1970s. Using historical plans and documents, the AQ-Arch consortium, consisting of DMAA and JWA, analysed and internalised the initial ideas of the original architect Karl Schwanzer in order to make a fundamental decision between demolition and conversion. With the help of BIM (Building Information Modelling), a digital twin of the existing building was created, which enabled comprehensive studies of the concrete cubature and the consequences of possible adaptations. The potential of the existing building with its economically optimised reinforced concrete structure, which was exceptional for the 1970s, was thoroughly examined in terms of statics, noise and fire protection as well as suitability in terms of building physics.
Characteristics of the existing building in its function as the headquarters of Bank Austria were the mirrored façade and a striking, expansive but almost unused staircase. The mirrored façade emphasised the hermetic nature of the building, while the monumental gesture of the external staircase dominated the Julius-Tandler-Platz area. The remodelling allowed these outdated stylistic elements to be removed.
Development of the new
One of the main focuses of the planning process was to create a new opening to the neighbourhood: new urban places to linger, semi-public spaces, barrier-free access and restaurants with open spaces were to be created. The dimensions and substance of the office building were retained, but new open spaces were created, making Julius-Tandler-Platz much more attractive with a new look and increased accessibility.
Situated nine metres above street level and above the tracks of the railway tunnel, the new plaza level in the inner courtyard links the valuable open spaces of Spittelauer Platz, Lichtentaler Platz and Julius-Tandler-Platz. Decisive premises of the project development were the pedestrian permeability, the opening to Julius-Tandler-Platz, the broadest possible mix of uses, the obligatory redensification of an urban core zone and the harmonious integration into the urban space.
The façade of the building was freed from its mirroring. The new stainless steel cladding of the façade has a glare-free and silky matt appearance thanks to its fine embossing, while the terraces create additional open spaces for restaurants and offices and a counter-design to the building’s previous seclusion.
Another planning focus was on the design of a vivid base zone. The extensive opening of the base achieves the desired spatial relationship to Julius-Tandler-Platz, makes the station hall more attractive and creates an inviting connection to the central plaza level. At the northern rear of the building, a connecting structure from the 1970s, between the office complex and the garage, was removed in order to return to Karl Schwanzer’s original idea of a solitary cubic building.
