The Kalle Neukölln project revitalises the historic Quelle department store on Berlin’s Karl-Marx-Straße. The large-scale building, together with its adjoining multi-storey car park dating from 1970, is one of the district’s key properties due to its prominent location along Neukölln’s central commercial and transport artery. A radical reprogramming of the property transforms the former department store into a diverse neighbourhood hub for creativity, culture and urban life.

The building is flanked by two listed structures. On Ganghofer Straße, the historic Stadtbad Neukölln is located directly opposite the site. The project therefore lies within the protected setting of the listed building and required close coordination with the heritage authorities.

Following the principle of rethinking rather than demolishing, the existing structural frame has been transformed into a contemporary environment for work, leisure, culture and social interaction. The project demonstrates how embodied carbon can be retained within the existing building fabric while simultaneously providing a forward-looking response to the structural transformation of the retail sector.

With a total floor area of approximately 40,000 sqm, the project creates a diverse urban environment that connects collaboration, culture and leisure across all levels. The programme comprises 4,000 sqm of rooftop garden, 26,000 sqm of office space and 4,000 sqm of retail space. At its centre is a 6,000 sqm hall dedicated to gastronomy, events and an indoor food market.

The transformation of the centrally located department store into Kalle Neukölln sends a strong signal for the reinvention of Karl-Marx-Straße as a vibrant urban artery at the heart of Neukölln. The new concept benefits not only the tenants but also visitors, local residents and the wider district. A diverse mix of uses and continuous urban activity — both indoors and outdoors, from the basement to the rooftop — are intended to mutually reinforce and inspire one another. Kalle Neukölln thus demonstrates how the latent potential of seemingly obsolete urban sites can be recognised and their genius loci harnessed for successful transformation.

Urban and Architectural Concept
In order to bring the building’s considerable volume closer to the historic grain of the surrounding city, the massing was conceived as a pair of architectural siblings. The façade design divides the large complex into two equal yet contrasting volumes.

The southern building facing Karl-Marx-Straße features a light-coloured loggia façade made of precast architectural stone with marble aggregate. The northern building facing Ganghofer Straße — the former multi-storey car park — is clad in a bronze-toned metal façade. The pronounced relief of its post-and-beam façade establishes a reference to the traditional articulation of the listed Stadtbad opposite.

At the location of the former spiral car-park ramp connecting the two building volumes, a winter garden has been introduced as an event space and a spatially connective element.

The redesign seeks to anchor the building volumes more firmly within the urban context of the surrounding listed buildings while making the programmematic transformation of the building visibly legible from the public realm. The architectural intervention is fundamentally based on the existing building fabric, with additions and subtractions limited to critical areas in order to establish a coherent relationship with the surrounding urban structure.

Embodied Carbon
The existing concrete structure was conceived in the spirit of its time with exceptionally large spans of up to 24 metres and features monumental concrete beams and columns.

The building’s concrete structure — which accounts for a substantial proportion of the embodied carbon associated with its original construction — has been almost entirely retained and deliberately left exposed, allowing its architectural and aesthetic potential to become visible.

Its reuse results in a significantly reduced carbon footprint compared with demolition and replacement construction and, in this case, even outperforms a new timber construction in terms of CO₂ emissions. The project therefore demonstrates the potential of retaining and reusing existing structures as a key strategy for sustainable construction.

Challenge
The structural transformation of the retail sector is affecting countless city centres. It calls for a fundamental rethinking of public space and will lead to profound changes in the configuration and use of inner-city areas.

There is still a lack of forward-looking strategies for dealing with the obsolete building typology of the inner-city department store, which is often located in precisely those strategically important and urbanistically sensitive sites that are crucial to the future development of the city.

Collaboration
The development of such sites requires close dialogue with their social and political context, as all stakeholders are particularly sensitive to changes in these prominent urban locations. A project of this complexity can therefore only succeed through the collaboration of different planning partners with complementary expertise.

The Berlin-based practice Realace developed the initial concepts, which were subsequently refined in cooperation with local political representatives and public authorities. The programme mix, mobility strategy, as well as social and cultural aspects were considered as integral components of the development.

Max Dudler developed and planned the project’s urban and architectural identity. The architectural practice Aukett + Heese was responsible for the realisation of the interior spaces.

Programme and Use
Kalle Neukölln is particularly suited to hosting unconventional events and activities. In close collaboration with local stakeholders, strong connections were established with groups and organisations based in the district, enabling a range of temporary uses, including events as part of the 48h Neukölln arts festival.

The distinctive character of the building is also reflected in its new tenant mix. The development is now home to the CODE University of Applied Sciences, as well as SoundCloud, the global music-streaming platform; Rough Trade, the legendary London-based music retailer; the startup accelerator Delta; and Kiez Büros, offering flexible office spaces for freelancers and small businesses.