Zurich Zoo’s new elephant enclosure is embedded in the extensive landscape of the newly designed Kaeng Krachan Elephant Park. Designed as a distinctiveshallow, freeform shell-structure built in a web of timber, the roof structure blends into the landscape.
The decision to use a timber structure was made due to the low weight of the material and the advantages in production.
Traditional carpentry firms were used for the timber construction. The pace of work was dictated by the construction workers; at times there were are many as 80 carpenters working on the roof simultaneously.
The individual pieces of the timber shell were CNC milled and assembled like a giant puzzle.
The roof is designed as a self-supporting, timber shell made of cross-laminated timber panels nailed together. These timber panels were malleable enough to be able to be bowed into the desired shape on site.
The panels of the first layer were curved over a formwork, while the panels of the second and third layer were nailed over it and rotated by 60°. The third layer already had the 271 curved cut-out shapes of the openings, which were later cut into the roof on site. Constructing the roof was like building an ark. Rather than high tech machinery, handcraft and sheer human power were needed to realise the unconventional shape.
The shell construction consists of cross laminated timber panels with standard dimensions of 3.4 x 12 meters, which are held together by almost half a million screws. The hall is illuminated by 271 skylights, which were cut out of the timber shell with the use of chain saws.
The self-supporting timber shell rests on a foundation in five positions on the edge. A prestressed concrete ring encircles it and is supported at the positions where it dips down.
The roof of the enclosure blends into the landscape as a free-form shell construction and dissolves into a net-like, organic structure that echoes the surrounding forest.
Inside the enclosure, sunlight creates an intriguing interplay of light and shadow as if through a forest canopy of leaves.