“Mirror Masterpiece for Museum Boijmans Van Beuningen”

Depot Boijmans Van Beuningen, designed by Winy Maas of MVRDV for Museum Boijmans Van Beuningen, is an architectural masterpiece in Rotterdam’s museum park. However, the mirrored design, intended to ‘compensate’ for the surrounding park, raised unique construction issues. Sorba, as the executor of this project, took up this challenge and completed the impressive glass façade in autumn 2020. Here, we unravel the secrets behind the development of this extraordinary façade.

Engineering: Challenges of the Spherical Shape

The biggest engineering challenge lay in the completely spherical shape of the building. Sorba engineers used points to create the 3D model, allowing the complex shape to be executed according to BIM standards. This ensured optimal cooperation with main contractor BAM and identified any problems as early as the design stage.

Architect: MVRDV

Contractor: BAM Bouw & Techniek Large Projects

Material: Double-curved mirror glass panels

: Double-curved Mirror panels

Glass was chosen to achieve the smoothest mirror effect. Using 26 layers of 64 double-curved glass panels each, a total of 1664 panels, Sorba created a spectacular mirror facade. Each layer had a unique radius of curvature because of the building’s bowl shape. The mirror coating, bending process and lamination of the glass required production in China. The matt film on part of the façade minimises reflections towards the nearby Erasmus Medical Centre.

Construction of the Façade

Sorba started with the rough concrete base and placed anchor rods which, due to the round shape, were accurately measured via the 3D model. After insulation, paying special attention to the strong curve, hook plates were mounted. The double-curved glass panels were attached to these, with black aluminium frames on the back. The complexity of the process required cooperation with Hoven Cranes for suspending the curved panels with a contramass lifting beam.

Insulated glass and Special Coating

Windows and doors followed the spherical shape of the building with special 3D deformed insulated glass panels. Transparency and mirror coating were combined with screen-printing techniques for a smooth transition between the mirror façade and the transparent section. The matt “cloud” on the façade minimises reflections to the neighbouring hospital.

Render Depot Boijmans van BeuningenDepot Boijmans van Beuningen | Sorba Projects

Vanishing Doors and Truck Lock

Sorba developed special doors, disappearing into the façade when closed, and bus door-like movements when opened. These doors, an engineering feat due to their size and fragility, were uniquely integrated into the mirrored design. The truck lock doors, 5.6 metres high and weighing more than 1,500 kg each, required extra attention and innovation in construction.

Roof terrace: the crowning glory

The mirrored-effect roof was constructed with aluminium composite and reflective top coating. The roof terrace, fitted with transparent glass panels with a gradual transition to the mirror façade, seems to float in the air.

Sorba: Surface Creators

Sorba’s involvement in the Depot Boijmans Van Beuningen project is a triumph of engineering, innovation and craftsmanship. The mirror masterpiece, initiated by Winy Maas, is not only an addition to the Rotterdam skyline, but also a testament to Sorba’s ability to push the boundaries of construction and aesthetics. The Depot remains an iconic example of the collaboration between architectural vision and engineering execution, and Sorba remains true to his pursuit of perfection in the built environment.


The mirror façade consists of 2 types of glass: laminated glass (full-surface mirror) and insulation safety glass (partly screen-printed).

Aluminium composite material (Alucobond), finish NaturAL Reflect 405, is used on the roof.

Surface materials used

  • The approx. 5750 m² mirror façade consists of 1664 glass panels.
  • Around 590 m² of aluminium composite material (Alucobond) was used on the roof.

Gert-Jan Nietsch

Neem contact op

Ook samen aan de slag?

Persoonlijk verbinding vinden we erg belangrijk, wij nodigen u uit om contact met ons op te nemen. Wij zijn er voor ú!