To the housing and urban-rural development administrative departments of all cities (prefectures):

In order to implement the "Work Plan for Accelerating the Transformation of the Construction Industry Development Mode and Promoting the Building of a Strong Construction Province" jointly issued by the Department of Housing and Urban-Rural Development and five other departments, to continuously deepen and enhance the five-year action to improve the development quality of prefabricated buildings, to focus on strengthening quality and safety management of prefabricated buildings, to improve the development efficiency of prefabricated buildings, and to promote the coordinated development of intelligent construction and building industrialization, the relevant matters are hereby notified as follows.

I. Improve the design level of prefabricated buildings

(1) Strengthen design management. For prefabricated building construction drawing design documents, a "Special Section on Prefabricated Building Design Description" shall be prepared to specify in detail the implementation of the prefabrication rate and technical measures. Construction drawing design shall comprehensively consider the relevant professional requirements of architecture, structure, mechanical and electrical systems, and decoration, and shall meet the needs of component fabrication, transportation, and construction. Design units are encouraged and supported to use Building Information Modeling (BIM) for professional design, analysis, and optimization. In the design of prefabricated residential buildings,

the proportion of four types of standard components—composite slabs, stairs, bay windows, and shear walls—shall be increased, striving to exceed 60%; in the design of prefabricated public buildings and industrial buildings, pipeline separation technology shall be fully implemented. For concrete buildings with a prefabrication rate greater than 60% or steel structure buildings with a prefabrication rate greater than 75%, the construction unit shall organize experts to demonstrate the rationality, feasibility, and economy of the design scheme; the design unit shall strengthen full-process tracking services and shall not subcontract the design of prefabricated building components involving structural safety to other units.

(2) Strictly conduct construction drawing review. The construction unit shall provide design documents that meet the depth requirements for prefabricated building design. Construction drawing review agencies shall conduct review in accordance with the "Standard for Assessment of Prefabricated Building" (GB/T51129), the "Review Points for Construction Drawing Design Documents of Prefabricated Concrete Structure Building Projects in Sichuan Province (Trial)", the "Review Points for Construction Drawing Design Documents of Prefabricated Steel Structure Building Projects in Sichuan Province (Trial)", the "Rules for Calculating the Prefabrication Rate of Prefabricated Buildings in Sichuan Province", and other relevant national and provincial provisions. For later-stage special designs involving the prefabrication rate (such as decoration and renovation), the construction unit shall provide the review agency with a commitment letter on prefabrication rate design; for design changes involving changes in the prefabrication rate, in principle the original review agency shall be responsible for review.

(3) Strengthen the promotion and application of new technologies. Enterprises are encouraged to promote and apply new technologies. For technical systems for which there are currently no national engineering construction standards, industry standards, or Sichuan provincial local standards, in accordance with the "Measures for the Administration of the Promotion and Application of New Technologies in the Field of Housing and Urban-Rural Development of Sichuan Province", the Department of Housing and Urban-Rural Development shall organize engineering technical experts to conduct technical demonstration, clarify whether the technology is applicable to the project and the conditions for meeting relevant requirements, and the demonstration opinions shall serve as the basis for project design.

II. Strengthen quality control of component production

Component production enterprises shall, in accordance with the relevant requirements of the "Measures for Assessing the Production Quality Assurance Capability of Prefabricated Building Parts and Components in Sichuan Province" and the "Guiding Opinions on Promoting the High-Quality Development of the Industrialized Parts and Components Industry of Prefabricated Buildings in Sichuan Province", effectively improve the quality assurance capability of component production. A traceability system for quality throughout the entire component production process shall be established; standard components shall be produced in accordance with standard drawings, and enterprise product standards shall be formulated; customized structural components shall be produced in accordance with relevant technical standards and design requirements. When concrete structural components leave the factory, a quality certificate and re-inspection reports or material certificates for main materials such as steel bars, sleeves, grouting materials, and lifting parts, a 28-day strength test report under standard curing conditions, and a component type inspection report shall be provided. When steel structure components leave the factory, a quality certificate and certificates for main materials such as steel, welding materials, and studs as well as test reports required by standards shall be provided.

III. Strengthen quality control during the construction process

(1) Standardize the acceptance of components upon entry. The construction, executing, and supervision units shall, in accordance with the "Standard for Acceptance of Construction Quality of Steel Structure Engineering" (GB50205), the "Specification for Fabrication, Installation and Quality Acceptance of Industrialized Concrete Precast Components" (DBJ51/T008), and other standards, organize quality inspections by component entry batch, and verify the type inspection reports for sleeve grouting connection products and the re-inspection reports on grouting material performance provided by the production enterprises. If the design documents do not specify clear requirements for component inspection, concrete components may not undergo structural performance inspection after entry, but physical inspection of the components must be carried out.

(2) Strengthen control of construction stages. The construction unit shall establish and improve a quality and safety assurance system, and formulate internal quality management systems for acceptance of precast components upon entry, quality control of node connections, and trial installation acceptance of the first floor or the first representative construction section. In accordance with construction drawing design documents (including detailed design of precast components) and the relevant standards for prefabricated buildings, construction organization design documents covering construction plans, precast component stacking, installation, node connections, and component support shall be prepared. Emphasis shall be placed on preparing special construction schemes for precast component support methods and installation of the first floor or the first representative construction section, and specific schemes shall be formulated for the sleeve grouting construction of vertical components, clarifying grouting technical standards, processes, techniques, and responsible persons for key positions. The construction unit shall organize skill training and assessment for sleeve grouting operators. During construction, grouting materials matching the sleeves must be used, construction may proceed only under conditions with the corresponding working environment, and on-site specimen performance testing shall be carried out according to the process flow.

(3) Strengthen the supervision responsibility of supervision units. Supervision units shall, in accordance with design documents and relevant standards, prepare special supervision implementation rules, specifying requirements for key stages, key parts, witness sampling, and on-site supervision, and implement them after review and approval by the construction unit. They shall focus on verifying the technical disclosure by construction management personnel for key processes such as precast component hoisting and node connections. They shall strengthen on-site supervision of key processes and key parts, including installation of the first floor or the first representative construction section, node connections of precast components, connections between prefabricated structural components and cast-in-place structures, and the grouting construction process. They shall conduct key inspections of the sealing and waterproofing construction of peripheral enclosure precast components, accept inspection lots and concealed installation of precast components, and form record materials. Concealed construction at all key nodes and key parts must be subject to signboard acceptance.

(4) Standardize completion acceptance behavior. The construction unit shall promptly organize the design, construction, supervision, and other responsible entities to carry out project completion acceptance, conduct a comprehensive inspection of the engineering entity, and form a four-party conclusion inspection report. The main inspections shall cover whether the project meets the design standards for prefabricated buildings and the design requirements for the prefabrication rate, whether all contractually agreed project contents have been completed, whether technical archive materials are complete, whether construction management materials are standardized, and whether the entry test reports for main building materials, building components and accessories, and equipment meet the conditions for completion acceptance.

IV. Improve the quality and effectiveness of engineering construction supervision

(1) Strictly supervise construction quality. Local engineering quality supervision and management departments shall earnestly perform their responsibilities for quality supervision and management of prefabricated building projects. Before process supervision, supervision work disclosure shall be conducted; during process supervision, supervision shall be strengthened over the performance of quality subject responsibilities and quality management process behaviors by construction, design, executing, and supervision units, with random inspections of the entry quality of precast components as well as the quality of the engineering entity structure and quality control materials. In specific implementation, supervision shall focus on the quality acceptance of each stage of major division (sub-division) projects, whether the organizational form, procedures, and implementation of acceptance standards for completion acceptance by responsible entities comply with relevant provisions, and whether acceptance conclusions are clear, and supervision opinions shall be formed. Where quality problems are found, rectification within a time limit shall be ordered, and investigations and handling shall be conducted in accordance with laws and regulations.

(2) Improve quality supervision methods. Local engineering quality supervision and management departments shall make full use of means such as "Internet + smart supervision", build and make good use of "smart construction site" platforms, collect basic information on prefabricated building projects, regularly carry out quality and safety data analysis, improve the supervision level of engineering project construction, and urge all responsible entities to strengthen management throughout the entire process of engineering quality construction. They shall continuously innovate supervision methods and approaches, incorporate mechanical operation status, personnel safety behavior and training, engineering data transmission and archiving, and implementation of institutional standards into the scope of informatized supervision, and enhance the intelligent and digital level of whole-process quality supervision of prefabricated buildings.

Department of Housing and Urban-Rural Development of Sichuan Province

September 12, 2023