焕然一新

Origin and story

Lu You's Lao Xue An Bi Ji, volume 8, records a wealthy merchant's restoration of the Puzhao pagoda at Sizhou near the end of the Xuanhe era. The merchant contributed a large sum to refurbishing it, and Lu describes its transformed appearance with the exact expression huan ran yi xin.

This is a documented Song literary use, not proof that the phrase was invented for that building. The words evoke a freshly bright, renewed appearance. They can describe the results of cleaning, repairs, redesign, or wider improvements; nothing in the idiom requires replacing an old object with a different one.