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From Wood to Architecture | Lookout Tower on Korkeasaari Island

Helsinki, Finland, 2002.

Design: Vile Hara

A student competition held in 2000 for the design of a lookout tower on Korkeasaari Island was won by the entry Kupla ("Bubble"). The Lookout Tower has a strong but light meshed shell structure built of timber strips. This allows unobstructed views in every direction, and the light, wickerwork-type tower becomes a subtle landmark for Helsinki Zoo in the seaside landscape.

The completely organic form was intended to be both individual and structurally feasible. Its implementation required persistent testing with models in order to bend and twist the timber to the design. The four-fold gridded structure proposed in the entry proved difficult to execute and was replaced by a simpler solution, with only two layers of overlapping timber strips. The strips were connected simply with bolts, as the meshed structure has over six hundred joints. The surface treatment was a linseed oil based wood balm, and its suitability for the weather conditions was also tested.

The tower was executed by a multinational group of students. Forcing the pre-formed timber strips into place proved more difficult than in the test conditions as the hot summer dried the timber and almost every single strip had to be steamed separately to fit the assembly. Once the form was finally complete and the accurate locations of the joints had been determined, the outer layer strips had to be detached one by one to install connectors in the joints.

Photos: Jussi Tiainen, HUT photography laboratory