Bao'an District of Shenzhen City housing based on "Housing DAMAGED grading standards (Trial)" (City live word (1984) No. 678) as well as the industry standard "dangerous building appraisal standards" (JGJ125), by examining the structure of housing, renovation, equipment , the fitness status of non-structural components and building appendages determine perfect grade of buildings. Housing End-destructive testing applied to assessment of housing, housing management, housing needs to determine the fitness level of the house. In the fitness detected if found houses exist affect the situation must promptly notify the principal house safety testing detected. After checking the condition of damaged houses generally include the following main elements: 1) to investigate housing construction materials. Including: Check out engineering geological survey report, design drawings, construction records, project completion and acceptance of information, as well as other relevant data and information that reflect housing construction situation; 2) to investigate the history of the house. Including: usage, inspection testing, maintenance, reinforcement, alteration, use change, conditions change and disaster damage and repair, etc.; 3) checked for consistency houses entity with drawings (text) data records; and 4) Check the house structural arrangement and construction of connections and structural systems; 5) Check measuring inclination and uneven settlement houses; 6) The text, drawings, photos or video and other methods, the recording house structural components (walls, floor, roof, etc.), decoration, equipment, non-structural components and building appendages (outdoor terrace, gutters, steps) of the damaged parts, the scope and extent; 7) analyze the reasons damaged houses; 8) houses the fitness comprehensive assessment of the situation. 2) detection and identification of housing safety.