Building appraisal is also in this order, first external after the internal, first upper after the bottom, first load-bearing components after non-load-bearing components, first local after the overall, first surface after concealment. Let's take a look at it together. First, the external after the internal 1, External: The main understanding of the structure of the housing type, structural appearance damage, the overall deformation, housing surrounding environment, Foundation Conditions; 2, the internal: The main understanding of the housing components of the working state and damage. 2. First the upper part and then the bottom part 1. The upper part: The main purpose is to understand the working state of the unfavorable structure in the upper part of the building, and to check the influence of whipping effect on the structure, especially the influence of temperature stress and deformation; 2. Ground floor: The ground floor is the most important part of the load-bearing floor, all kinds of forces are relatively concentrated, when the ground floor deformation, cracks, etc. . 3. load-bearing member first and then non-load-bearing member 1. load-bearing member: to know the working state and damage condition of load-bearing member of building structure, and to judge whether there is failure state; 2, non-bearing structure: The main understanding of non-bearing components of the structure, connection, integrity, firmness, damage and so on. Part of the first part of the whole 1, part: The main part of the housing structure to understand the damage status, to determine whether it is an isolated event, whether the impact on the whole. 2. WHOLENESS: The main purpose of this paper is to find out the complete and damaged condition of the integral structure of the building, especially to check out the cracks of the members caused by the lateral displacement and horizontal deformation of the whole building, and to analyze the whole structure according to the concept of force transfer tree, find out the problems in time and distinguish whether there is an influence relationship between the part and the whole. 5. Surface first, then hidden 1. SURFACE: the surface of the structural components through the surface damage survey, when the internal defects are suspected, the necessary in-depth testing should be conducted. 2. CONCEALMENT: Inspection of the concealed part of the structure should be carried out mainly through the regular surface phenomena of the structural members or when the upper part of the structure has obvious characteristics of the problem caused by the damage of the lower part of the structure.