Granite® HDX: An aesthetic & sustainable cladding material for Stoas Vilentum University

Detailed information

The three-story building, developed by the Dutch architectural firm BDG Architecten Ingenieurs Zwolle, was designed to express 'ecological intelligence,' the university’s philosophy which refers to the areas of learning and development, human behaviour, relationships between man and nature, ecosystems, and sustainability and constitutes the basis for training at Stoas.

The building's cylindrical shape was chosen deliberately as it stands for non-hierarchical structures. Teachers and students are treated as equals, and each floor has essentially the same shape and the same view. Furthermore, the cylinder offers the most favourable ratio of floor area in relation to the exterior wall surface. The energy loss through the walls is minimal.

Facades: steel & glass

The facades are continuously glazed to provide natural light. Between the horizontally arranged floors, irregularly perforated steel elements envelope the building. These steel elements of different heights define the size of the windows acting as sun shades by overlapping some from above or below in areas where less natural light is needed. This way, the steel part of the facade defines the size of the windows in each room resulting in an irregular pattern of horizontal lines in the building's facade.

Granite® HDX: aesthetics, durability, and protection

The material used for the steel cladding elements is double sided organic coated steel with Granite® HDX 55mµ paint system. This coated steel forms part of ArcelorMittal's Nature range of organic coated steel building solutions and as such is free from heavy metals and chromates.

The perforated Granite® HDX coated steel sheets reveal the yellow external wall of the building. Sunlight and clouds create a constant play of light and shadow which add visual interest and highlight the landmark nature of the building.

Jack Muller B.V., a steel service centre specialising in organic coated steel, fabricated the perforated steel sheets, which were installed under the supervision of ZND Nedicom.  ArcelorMittal Flat Carbon Europe supplied Granite® HDX coated steel on both sides in the colour RAL 7039.

The advising role of Jack Muller together with ArcelorMittal enabled ZND Nedicom to adapt the best possible solution for the application. The architects had initially selected another material for the project, but Granite® HDX turned out to be a more sustainable alternative. Granite® HDX comes with a standard substrate which is zinc coated to 275 g/m², enough to guarantee it against corrosion for an automatic 30-year guarantee.

However, BDG Architecten were concerned that the perforations may compromise the integrity of the substrate over time and wanted reassurance from ArcelorMittal that Granite® HDX could withstand corrosion after perforation. ArcelorMittal’s R&D team calculated different options before specifying a 350 g/m² (Z350) zinc substrate. The cathodic protection of zinc will prevent the cut edges of the perforations from corroding for many decades.

Cave & nest – interior spaces

For the internal organisation of the school, the starting point were the concepts of the 'cave' and the 'nest.' Whereas the nest is a very rational space that a bird makes extremely functional and rebuilds each spring, in the non-rational cave the residents comply with the existing space and arrange themselves according to conditions and needs. The school consists of a combination of functional nest spaces, such as labs and offices, and the cave spaces in between are the passing areas where the uses are unpredictable.

The construction offers maximum flexibility with three floors arranged around a large void - a central space covering the total height of the building with crossing staircases that provide access to all floors. The open structure promotes the interaction between teachers and students.

The building, construction, and installations are not opposed to each other, but rather form a unity with the users. The installations are visible and integrated in a smart way making the school energy efficient and sustainable. In line with the university's vision of education, the design emphasises the fact that everything is related and can only be understood in relation to each other.

Architecture & landscape

The architecture and landscape are intertwined due to the location of the building on a green mound. Therefore, it is situated slighty higher than the rest of the building on the campus surrounded by slopes of grass. For the perforated exteriors and also on the floors, the motif of a mycorrhiza was chosen, a symbiosis between fungi and plant roots with a filamentous structure. The mycorrhiza symbolises the intelligent connections within a synergy corresponding to the concept of '”the whole is more than just the sum of its parts.” Incorporated ecological structures can be found in many other parts of the  building.

Stoas Vilentum University occupies a prominent place on the campus in Wageningen, which will develop into an ideal environment where learning, working, and living together will prosper in the coming years.