On the other hand, yarido were used as an external partition and seems to be the lightweight form developed from tsumado, and the openable and closable yarido was an innovative fitting as an alternative to the clay wall of plaster which was not adequate for the humid climate of Japan.
一方遣戸は、外回りの隔て建具として使用され、妻戸を軽量化した発展的形態と考えられるが、開閉自在の遣戸の誕生は、湿度の高い日本の風土にとって不向きな塗り込めの土壁に代わる革新的建具であった。