• Mediacite inside
  • Mediacite inside at night
  • Mediacite inside view
  • Mediacite outside
  • Mediacite roof - red sections
  • Mediacite second level

1 / Introduction

The addition of a stunning roof to the Mediacite retail centre in Liège was a late addition to the architectural design, added by a brave client with the vision and determination to create a landmark for the community. Mall design and construction of the main buildings were well under way by the time BuroHappold came on board with the architects to design the centre piece of this new development.

Key facts

  • Intersecting ribs span 35m long X 30m wide mall space
  • Hybrid structure takes advantage of shell action and resolves inconsistent boundary conditions of concrete structure underneath
  • Efficient procurement with local steelwork contractor on site

The Project Details

  • Client:
    Wilhelm and Co
  • Architect:
    Ron Arad Architects
  • BuroHappold services:
  • Structural engineering

2 / Challenge

There were two major challenges around this project based on the tight deadlines which necessitated creating failsafe design and implementation solutions. Firstly the scheme was taken from initial sketches to a buildable scheme in a very short period of time working very closely with Ron Arad and his team. Secondly in terms of implementation, gaining control of the procurement process and bringing in a fabricator early on was vital to reduce risk.

3 / Solution

The process of designing the initial sketches to actually building the roof took place in record time. We worked in close collaboration with the architects to develop the conceptual ideas and design of the canopy based on intersecting ribs that follow and describe the 35m long x 30m wide mall space into a structure rather than merely a decorative element.  This involved an initial period of optimisation of the number of ribs, their depth, their makeup and their arrangement. We investigated the geometrical characteristics of the roof shape, making maximum use of shell action and allowing the ribs to flow as freely as possible.

The structure, which is triangulated only in areas of movement joints and fire curtains, pushes the steel ribs to a maximum, relying on their axial strength as well as their bending resistance.  The structure is a hybrid that takes advantage of shell action where possible but also resolves the often inconsistent boundary conditions presented by the concrete structure underneath.  All details, as well as the end points and transitions of the different parts of the mall roof were designed following a clearly aligned structural and architectural logic which is visible and can be experienced throughout.

Knowing that time to completion was very short the BuroHappold team drove the procurement of this unique structure.  A two-stage tender based on a highly selective tender list ensured risks were minimised and the fabricator could be brought into the process as early as possible to construct the ambitious canopy within budgetary constraints.  Belgian Steelwork contractor Lemants joined the team six months into the design and proved an invaluable partner in developing and value engineering the scheme.

We used a parametric design approach from the start of the project, moving from the sketch models that developed the sculptural qualities of the roof to a fully scripted data transfer process between architect, engineer and fabricator, including all steps of the analysis and the production of fabrication information. Drawings were illustrations and information exchange was fully digital.

The project went on site after less than 10 months taking it from concept to fabrication drawing.  Whilst the interfaces with the existing concrete structure beneath created some challenges, the insertion of this sculptural piece of roof structure into the concrete base structure went surprisingly smoothly, considering its late introduction.

4 / Value

The client’s visionary gamble has paid off.  Mediacite has had virtually full retail unit occupancy since it opened in late 2009.  The roof has transformed Mediacite from a mundane shopping centre into a fantastic architectural experience attracting visitors. As a guest at the opening said: “It puts a smile on my face”.