High Quality Content by WIKIPEDIA articles! Declared historic buildings of Hangzhou, China, are districts, artifacts or buildings legally declared to be "protected". According to the "Regularations of historic districts and historic buildings in Hangzhou" effective from 1 January 2005, historic buildings are those artifacts or districts that have lasted more than 50 years, and of significant values for history, science, and art study. In Hangzhou, declaring a historic house requires consulting the urban planning administration bureau, and the real estate administration bureau.