General information

  • Location address
    Landkommanderij Alden Biesen, Kasteelstraat 6, 3740 Bilzen
  • Location country
  • Year of construction
  • Name of the client/building owner
    Flemish Community
  • Function of building
    Entertainment & recreation
  • Degree of enclosure
    Open structure
  • Climatic zone
    Temperate - cold winters and mild summers
  • Number of layers
  • Primary function of the tensile structure
    • Rain protection


The Grand Commandery Alden Biesen (Bilzen) was the headquarters of a province of the Teutonic Order (established in 1190) in the land of Maas and Rhine. Nowadays Alden Biesen is a cultural centre of the Flemish Community. It is a congress centre as well as a cultural and tourist attraction. Four umbrellas have been designed for the courtyard of the historic castle. Because the castle is a listed monument, the umbrella’s have been built without ‘touching’ the building. Each umbrella is placed on a central pillar at a height of about 10m. The umbrellas slightly overlap to fully protect the space from rain. Rainwater is evacuated through the pillars. The plan of each umbrella is inscribed in a square of 13m x 13m.
The umbrellas are adapted to fit in the irregular shape of the inner court and hence are all different. In the unfolded configuration the height of an umbrella is 3m, when folded the height is 8m. The objective of creating an
adaptable cover in the courtyard is fully realised: in winter the umbrellas, which stand folded, are unfolded (the computer controlled sequential unfolding takes 4 minutes for the 4 umbrellas) to shelter the space for outdoor concerts, while in summer they are operated according to the weather and either protect from rain or from too much sun. The almost white PVC coated polyester fabric has enough tranclucency to allow the daylight to be only slightly filtered through the skin. The
redness of the brick façades is reflected and creates a warm coloured ceiling. Once the umbrellas are closed, they appear white again.
The inner courtyard has been used regularly throughout the past years and the system controlling the folding (as well as
the setting of the pretension) of the umbrellas proved to work as expected. A thorough technical maintenance is performed every year. [Tensinews 14, 2008]

Description of the environmental conditions

Material of the cover

  • Cable-net/Fabric/Hybrid/Foil
  • Material Fabric/Foil
  • Material coating

Main dimensions and form

  • Covered surface (m2)
  • Total length (m)
  • Total width (m)
  • Form single element

Duration of use

  • Temporary or permanent structure
  • Convertible or mobile

Involved companies