In 1952, Sumiya's building was designated as a national important cultural property by the government, based on the fact that it was the only surviving ageya structure that was built when Sumiya moved to Shimabara (except for the Matsuno-ma room, which was destroyed by fire at the end of the Taisho period).
昭和27年（1952年）、嶋原が開かれて以来現存する唯一の揚屋の遺構として国の重要文化財に指定された（ただし「松の間」のみは大正末期、火事により焼失してしまい指定されていない）。