Our Easter egg comes from the Netherlands. In the spirit of “architecture parlante”, the “Tij” bird observation stand by RO&AD and Rau Architekten also expresses its function in its form. The observatory looks like a straw egg.
Our Easter egg comes from the Netherlands. The Tij bird observatory by RO&AD and Rau Architekten also expresses its function in its form in the sense of “architecture parlante”. The observatory looks like a straw egg.
Built exclusively from renewable raw materials, the “Tij” lookout is located in the delta of the Rhine and Meuse rivers near the town of Stellendam. In Stellendam, a barrage has been closing off the Haringvliet, a former estuary between Hollands Diep and the North Sea, since 1970. The dam changed the Haringvliet from salt water to fresh water. This had an enormous impact on flora and fauna. For 30 years, there have therefore been plans to allow salt water back into the Haringvliet by at least partially opening the barrier. However, it took until 2018 for the plan to be realized against much resistance. As part of this “re-naturalization”, RO&AD(see Baumeister 2/2021) and Rau Architekten built the egg-shaped bird observatory “TIJ”.
The name “TIJ” is a play on words. On the one hand, Tij means “tide” in Dutch and refers to the return of the tides to the Haringvliet. On the other hand, “Tij” also sounds like “het Ei” – the egg, if you pronounce it quickly.
The artificial egg consists mainly of a wooden structure and a reed shell. The wooden construction is designed as a so-called Zollinger construction, a segmental construction method that allows vault shapes to be created with economical use of materials. RO&AD and Rau built the lower part of the ice, which is regularly flooded during high tides, from Accoya, a specially treated timber, and the upper part from pine. The 400 or so individual parts of the timber construction were computer-manufactured in Finland, shipped and assembled on site. The reeds for the building envelope, on the other hand, grow just behind the Tij bird observatory. However, the reeds do not cover the entire wooden frame, but only the parts that cannot be flooded by the sea.
Visitors enter the egg through a tunnel so as not to disturb the birds. The tunnel consists of former mooring bollards and planks made of Azobe. The planks were previously used in the brick industry. The tunnel is covered with sand, which will serve as a breeding ground for the waders. The entire egg is designed as a potentially temporary structure that can be dismantled and reused at an unspecified time in the future.
An egg as a sauna in Kiruna, Sweden: a project by artist duo Bigert & Bergström.












