The annex building received the Kanagawa Architecture Concours Grand Prize in 1984, and the BCS (Building Contractors Society) Prize in 1985. In contrast to the light and airy impression of the main Kamakura building, the Annex fs design and materials convey a sense of volume and solidity. Upon completion of the annex, the museum received a donation of valuable works by the nihonga painter Hoshun Yamaguchi and the artist fs personal library.
The current renovations have seen the replacement of the electrical and ventilation equipment, which had grown somewhat worn out in the over thirty years since the building's completion, and the renewal of the exhibition gallery walls. Also, a café and a curator's room have been added. The renovated building maintains Otaka's distinctive exterior, with the newly added sections constructed in a bright, airy style based in white to complement this design. Planning for the renovations began in 2015, with construction work commencing in February 2018, and completed in May the following year. After the completion of electrical work, the building re-opened in October 2019.
[Image above: Gallery 1984 / below: 2019]