The design of the pavilion is based on morphological principles of the plate skeleton of sea urchins. Following the previous research building by the same project team, the forest pavilion at the 2014 State Garden Show in Schwäbisch Gmünd, the BUGA Wood Pavilion pursues the research goal of taking the architectural design and structural performance of biomimetic segmented wooden shells to a new level: Is it possible to build a shell that reaches three times the span with the same small amount of wood per square metre as the forest pavilion? And can this structure be designed to be completely reusable so that it can be dismantled after the BUGA without any loss of performance and rebuilt at another location?

To achieve these goals, the pavilion utilises the biomimetic principle of ‘less material’ through ‘more form’, both in terms of the overall construction and at the level of the individual segments. In order to minimise material consumption and weight, each timber segment consists of two thin panels planking a ring of edge beams at the top and bottom, forming hollow, large-format timber cassettes with polygonal shapes. The base plate contains a large opening that allows access to the concealed bolt connections during assembly and at the same time creates a special architectural appearance. The lightweight segments are connected by finger joints that follow the morphological principles at the edges of the sea urchin panels. When assembled, the wooden shell acts as a form-active supporting structure thanks to its expressive, double-curved geometry.

As part of the project, a novel, transportable, 14-axis robotic timber production platform was developed for the automated assembly and milling of the pavilion's 376 customised segment components. During production, the wooden cassettes were first assembled by the robots. On average, the robotic joining took 8 minutes per segment. High-precision milling took a further 30 minutes.

This manufacturing process ensured that all the wooden segments could be assembled like a large, three-dimensional puzzle with an accuracy of less than one millimetre. With minimal use of materials, the breathtaking wooden roof spans 30 metres over one of the BUGA's central concert and event venues, creating a unique architectural space.

The completely prefabricated timber cassettes were assembled on site by a team of two craftsmen in just 10 working days without the need for the usual extensive substructures or supporting scaffolding. After connecting the segments using reusable bolts, these high-performance joints were sealed with HERTALAN® EASY COVER EPDM membranes. For this purpose, eight 1.5 mm thick EPDM membranes were laid loosely on the supporting shell and the edges and seams were glued to ensure watertightness.

Untreated larch panels form the visible exterior panelling of the pavilion. All construction elements are designed for easy dismantling and reassembly at another location.

Erich Hinz, CARLISLE® Field Consultant, and Oliver Glöckner, CARLISLE® Application Technology, supervised this exciting project from the initial design planning stage and supported the development with their many years of experience in the field of EPDM waterproofing.

Here you can find more information on prefabricated EPDM membranes.

Dimensions
approx. 32 x 25 x 7 m (LxWxH), usable area approx. 500m², shell area 600m², surface weight of load-bearing timber construction 36.8kg/m²

Construction
Load-bearing shell: robotically manufactured hollow cassette segments made of laminated spruce veneer lumber with UV protection, facing shell: HERTALAN® EPDM waterproofing, 3-axis CNC-cut untreated larch three-layer panels