 Whilst Maekawa Associates added a new annex in 1979 and in 1998 in conjunction with the Ministry of Construction, Yokoyama Engineering and Shimizu Construction installed earthquake resistant foundations to the museum.In 1998, the importance of the structure was underscored when it was included in the former Ministry of Construction's survey—as one of the hundred selected public buildings (the "Kokyo Kenchiku 100 Sen") which are outstanding and "well established in the local community.