Xinji Emporium in Harbin is a two- storey public building with a one- storey basement.The plan view of two?over?ground floors is in a concave shape, and the size of the concave area is 81 4m @ 151 0m.The owner of the building?requires that two storeys be built on the basement in this area.All the building in east, south and west directions to this area?is two- storey frame structure with a one- storey basement.Considering there is a column in each corner, two remodeling?schemes, / suspended structure method0 and / supported structure method0 are proposed.The design ideas, detail of joint and?problems worthy of note during construction are introduced respectively.It can be served as reference for the design of similar?project.