With the completion of the annex, including four floors above ground and eight floors underground, with all of the underground floors allocated for the stack space, the NDL grew to a massive library that could accommodate a combined total of 12 million volumes.
地上4階地下8階で広大な地下部分をすべて書庫にあてた新館の完成により、国立国会図書館は全館合計で1200万冊の図書を収蔵可能な巨大図書館となった。