The 2-storey city library is situated about a 10-minute walk from Komine Castle, a well-known heritage built more than 600 years ago and now a landmark of Shirakawa City.
Designed to maintain the visibility of the castle, the 3,000m² library is covered by a long-span pitched roof. As the roof surface slopes down, nearby residents can still enjoy a view of the ancient castle wall and the Tenshu.
3,900m² Floor area
10.8mLongest span of the roof
Pitching down from 12.7m the highest to the ground floor, the roof itself is also a strong architectural expression. As the structural engineer, Arup adopted a long-span steel bow truss system to realise the roof structure. The truss stretches 14.4m long in total, with 3.6m cantilevering outside the building. It is also the most economical scheme to withstand an estimated 0.9m deep snow load in this district.
The reading area on the ground level was planned not to have braces along the perimeter façade in order to ensure the continuous horizontal views. The superstructure, therefore, relies on reinforced concrete to resist the lateral load and to accommodate the reactions from the long-span steel bow truss. The roof structure unites the second and the third floor, creating a complex situation for the building. Three-dimensional analysis software, Midas/Gen was thus used to verify the actual stresses on the members of the pitched steel roof.
Good lighting Award 2011
33rd AIJ Tohoku,Tohoku architecture prize
30th Fukushima Architecture and Culture Award