Finnish Nature Centre Haltia, designed by Rainer Mahlamäki, was the first public building built from prefabricated solid-wood panels. Everything except the basement is made entirely of wood. Haltia aims to lead by example: to be the flagship of wood construction and inspire the Finnish construction sector to increase its use of wood in public buildings and apartment blocks.
Wood construction is naturally ecological, since the carbon footprint of wood is smaller than that of concrete. The solution used at Haltia also includes various special features that make it even more ecological.
The exterior surface of the building is made of silica-impregnated pine, which contains nothing that is environmentally harmful. It is as rot-proof as the arsenic-containing pressure-impregnated timber alternatives, and is also fire-resistant. Haltia is the first building in the world that uses this ecologically friendlier wood material for exterior cladding.
Construction causes 30–40 per cent of the world’s carbon dioxide gas emissions. One cubic metre of wood binds about a tonne of carbon dioxide from the air. More than 1,000 m³ of spruce was used for Haltia’s solid-wood frame. The use of wood thus reduces emissions and removes greenhouse gases from the atmosphere.
The frame of the building is made of prefabricated CLT or cross-laminated timber panels. The system is produced by Stora Enso Oyj and enables the use of solid wood in load-bearing structures in the walls, intermediate floor, and ceiling. No load-bearing columns or beams are needed. Thanks to the prefabricated CLT elements, builders were able to start indoor construction relatively quickly, and the building was completed in around 18 months.