The term "uncompleted residential flats" originated in Hong Kong and refers to the uncompleted properties (i.e. properties under construction). If the house built by the development company is the fruit after completion, then the building under construction but not completed by the development company can be regarded as the flower of this fruit. This further leads to the sale and speculation of "uncompleted residential flats". Generally speaking, selling "uncompleted residential flats" is a pre-sale house, and buying "uncompleted residential flats" is a pre-purchase house.