Kyklos Building | UNStudio

Belval is a redevelopment project that has successfully transformed an old industrial site in Luxembourg into an urban centre that now houses a university and technological centre, residential and office spaces, in addition to hotels and retail. Kyklos will be the last building to shape the Central Square district.

UNStudio’s building proposal for Kyklos (the Greek word for ‘circle’) aims to achieve the smallest possible carbon footprint. The design team, with local partner HYP Architects, using the early prototype of the Carbon Builder, a tool in development as part of a fully-fledged sustainable design framwork, reduced the carbon footprint of the design concept for this building by around 80% compared to a traditional office building in Luxembourg.

The use of recycled locally produced steel and working with concrete producers to improve the performance of the material, resulted in the choice of a hybrid steel-concrete structure. It was determined that this hybrid solution offered a better carbon performance in the long run. This early concept best possible roadmap demonstrates an ambitious possibility of achieving an important reduction of the carbon footprint compared to a typical office building in Luxembourg.

The Kyklos building has the ambition to achieve a minimum of BREEAM Excellent and Well Gold.

A response to context
 
Urban integration and a holistic sustainable approach are the two main drivers of the design of all elements of Kyklos, from its functional organisation to its construction techniques and its materiality.

The building is intended to be the centerpiece of the Agora Masterplan and is strategically located in the centre of the development, next to ‘Place des Bassins’. The emblematic concept connects two basins - remnants of the former steelworks site on which the district is developed - in the form of a singular ‘infinity loop’. This loop symbolises the alliance of the industrial site and its revitalisation as an urban space. Due to its proximity to the square, the building is envisioned as the third loop in this equation: a sustainable connection that represents the future of the urban development.

The design considers the master plan, the main pedestrian path, and the existing main square, to create a building that is inspired by and complements its surroundings. The result is the combination of the circular geometry of the square with the orthogonal geometry of the surrounding buildings.

Transparent urban integration
 
The lobby is designed as a unified space comprising both the main reception and commercial functions that are directly accessible from inside and outside. From here a large, circular staircase forms a visual connection with the Place des Bassins outside, while encouraging users of the building to use the stairs, rather than the elevators.

Numerous strategies are incorporated into the design of Kyklos to ensure high levels of transparency and daylight. These strategies made it possible to have 90% glazing on the ground floor and 80% on the upper floors. One corner of the building is setback on the lower levels, creating an overhang that further serves to protect from overheating.

The floor plates of the Kyklos building branch from the circular core and are suspended from steel cables. This eliminates the need for load bearing columns as much as possible and frees up the floors for a variety of possible interior layouts. The design of the building also ensures flexibility for possible use changes in the future.

UNStudio Team: Ben van Berkel, Arjan Dingste with Stella Nikolakaki, Bruno Peris Vila and Cristobal Ignacio Burgos Sanhueza, Laura Lopez Iglesias, Regiane Fernandes de Oliveira, Taliia Nurutdinova.

Local Architect: HYP Architects

Advisors: renderings by Play-Time Barcelona