The nature and approach of the national construction laws and regulations in Iran have a commanding and mandatory tone, and have a prescriptive approach, and pay more attention to the technical instructions of construction, which have an immaterial essence and are within the scope of engineering knowledge, and pay less attention to the functional approach. which is aimed at the building that has a material substance, in relation to the users, the requirements of life, and how they are satisfied with the built buildings. Accordingly, with the widespread occurrence of construction violations, the need to address the nature of existing national regulations and their approaches is raised as an important issue. The research question is, what is the nature and approach of compiling and enforcing national building laws and regulations? What are the causes of violations of laws and the occurrence of construction violations? The main purpose of the research is to improve the quality level of residential buildings by complying with the national building laws and regulations, and to identify the main causes of construction violations. The current research is in the category of applied research with an exploratory nature in terms of its purpose, and in terms of the data collection method in the category of descriptive research. The research method is a combination of qualitative and quantitative methods resulting from the comparison of the prescriptive approach with the functional approach in the preparation of national building laws and regulations, and in order to determine the causes of violations of the laws and the occurrence of construction violations, the existing cases of the Article 100 Commission were examined. . Based on the opinion of engineers, the statistical society includes the experts of the Article 100 Commission, and the administration of the municipalities. The results of the research show that the main causes of construction violations include: 1- The view of income generation and economic profiteering (40 percent) 2- Improper approach to drafting and enforcing laws and regulations (35 percent) 3- Improper performance of the municipality in dealing with violations (21 percent) 4- lack of education and awareness of the laws and regulations (4 percent). Therefore, with the comprehensive movement towards passing the prescriptive approach and on the other hand, moving towards the revival of the functional approach in different cultural, national and ethnic positions, etc., it can create a link between laws, technical and construction principles, requirements and needs. be users. The most important shortcoming of the upstream documents of the existing laws and regulations is not having a comprehensive and complete approach in the formulation and enforcement of architectural and urban planning laws and regulations, which by establishing a link between the goals of the functional approach and the prescriptive approach, a more comprehensive planning for the formulation of laws and regulations can be achieved. and reducing payment of construction violations.