Accurate policy, real-time supervision of the whole process, wade out of the "Nanjing experience" in the development of prefabricated buildings

Source：TBT Release Date：2024-1-3

Be Read：155Frequency

As the first batch of national prefabricated building demonstration cities, Nanjing has effectively promoted the continuous development of the local prefabricated building industry through the implementation of a series of innovative measures in recent years, and the market acceptance is getting higher and higher. During the "13th Five-Year Plan" period, the city has accumulated more than 320 new prefabricated building projects, with a total construction area of 27.02 million square meters, and the proportion of newly started prefabricated buildings in the newly started construction area of the year has increased from 10.34% in 2016 to 38.72% in 2020.

Unlike many cities that use the data of "prefabricated three panels" (prefabricated internal and external wall panels, prefabricated stair panels, prefabricated floor panels) to calculate the development results of prefabricated buildings, Nanjing has taken the use of "prefabricated three panels" as a basic requirement from the beginning, and projects that only use "prefabricated three panels" are not included in the statistical category of prefabricated building area. In this context, the city's prefabricated buildings accounted for 38.72% of the newly started construction area in 2020, which is more valuable than other cities in the country.

At present, many cities feel that the development of prefabricated buildings is difficult, can not push down, can not push, the market acceptance is not high, a variety of "complaints" can be described as endless, Nanjing is full of confidence, is one of the more typical "alternative", how did the city do it? With these questions, the China Construction Newspaper prefabricated building research group recently made a special trip to Nanjing urban and rural Construction Committee to visit and research, and Nanjing Construction industry modernization promotion work leading Group Office (hereinafter referred to as the "Industry Office") the relevant person in charge of the discussion, in order to explore the city's typical practices and experience in the development of prefabricated buildings.

Advance in different areas, control at the source, and take careful measures

In September 2016, The General Office of the State Council issued the Guiding Opinions on Vigorously Developing prefabricated Buildings, and then various localities issued specific implementation opinions of the local version. In August 2017, the General Office of the Nanjing Municipal Government issued the "Implementation Opinions of Nanjing on Further Promoting the Development of prefabricated Buildings", which clearly put forward a set of policy measures in administrative approval, incentive guidance, financial subsidies, industrial support and other aspects. According to Xu Hongfang, third investigator of Nanjing Construction Industry Modernization Promotion Leading Group Office, the implementation opinions from drafting, solicitations to formal introduction after nearly a year, on the basis of full research and discussion of all relevant departments, Nanjing has become a landmark document to comprehensively promote the development of prefabricated buildings, and according to the plan has been implemented until the end of 2020.

In promoting the development strategy of prefabricated buildings, Nanjing City adheres to the principle of "highlighting key points and promoting by classification", and divides the development of prefabricated buildings in the city into three types: key promotion area, active promotion area and encouraging promotion area. On the wall of an office of the Industrial Office, there is a schematic diagram of Nanjing's prefabricated building promotion area, clearly describing the specific boundary scope of the three areas, and next to the schematic diagram are relevant documents on the development of prefabricated buildings at the national, provincial and municipal levels.

In order to promote the real landing of prefabricated building projects, Nanjing City is led by the Industry Office, multi-department linkage, and controls the land transfer source, and the transfer indicators should indicate the relevant requirements of prefabricated buildings. Different from other places, Nanjing has defined three core control indicators for projects that should adopt prefabricated buildings: prefabricated buildings must be used in the same plot; The prefabrication rate of single residential building shall not be less than 50%, and the prefabrication rate of single public building shall not be less than 40%; Residential buildings (except low-rise dwellings of 3 floors or less) shall be delivered as finished housing.

For why the requirement "must be used in the same plot", Xu Hongfang explained that many cities only require prefabricated buildings in the same plot to reach a certain proportion, and many developers tend to leave the prefabricated building part to the second or even the third phase of development, which disrupters the overall rhythm of the city and leads to the overcapacity of parts in the regional market. It affects the sustainable development of prefabricated buildings. In addition, if there are prefabricated buildings in a certain plot, it is also fairer and more convenient for buyers to choose, and it also effectively avoids the emergence of some social contradictions or disputes. "The implementation of finished housing delivery for residential buildings" is conducive to the overall promotion of prefabricated buildings and finished housing, synchronous design and synchronous construction, which can avoid the waste of resources caused by secondary decoration, demolition and transformation, and truly reflects the significance of promoting prefabricated buildings.

In terms of incentive policies, Nanjing gives 2% of the total construction area reward to projects that meet the requirements of prefabricated building indicators, and part of the reward area is exempt from land transfer fees; If prefabricated building indicators are met and prefabricated outer walls are used, the horizontal cross-sectional area may not be included in the floor area calculation of plot ratio; Prefabricated buildings with a prefabricated rate of not less than 30% can be invited to tender. The Nanjing version of the implementation opinions also devoted about 500 words to clarify how to apply for awards and the processing process of relevant departments.

There are other areas of Nanjing's policy that are very noteworthy. For example, real estate development enterprises generally want to pre-sell as early as possible and supplement cash flow in a timely manner. To this end, the incentive policy is proposed in many places, and the image progress of prefabricated building projects can reach ground ±0.00 to apply for presale. In order to prevent enterprises from "taking advantage of loopholes" in this regard, Nanjing City stipulates that the "Commercial housing Pre-sale License" can be handled in advance when the foundation construction is completed, the first piece of prefabricated components is assembled and the installation begins. At the same time, the operation process is further refined: The industrial Office shall establish an expert database, coordinate the use of special funds, organize experts to demonstrate technical plans and identify indicators for free before submitting the project construction drawings for approval, strictly check the rationality and feasibility of the application of prefabricated technology and the accuracy of index calculation, and put forward optimization suggestions for projects with unreasonable technology selection, so as to facilitate the deepening design and adjustment of construction drawings. Reduce the appearance of assembly for the sake of assembly and only index theory; After the completion of the review of the construction drawings and the implementation of the confirmed expert arguments, the industrial Office will issue the approval comments as the basis for handling the pre-sale license, to prevent the problem that the application plan is inconsistent with the construction drawings, and to ensure that the application of prefabricated technology is implemented.

In addition, Nanjing Urban and Rural Construction Committee also issued the "Nanjing prefabricated building engineering quality safety management Measures", "Nanjing prefabricated building quality supervision Rules", "Nanjing prefabricated building concrete structure engineering construction safety management points", "Notice on strengthening the inspection and management of Nanjing prefabricated building concrete structure engineering" and other documents. Further clarify the prefabricated building construction, design, construction, supervision, testing and parts production enterprises responsibility and supervision and management requirements. In recent years, two prefabricated construction projects in Nanjing have won the "Luban Award".

Online services and real-time supervision of the whole process

At present, all industries are transforming to digital. In 2019, Nanjing began to carry out BIM whole-process application demonstration base and demonstration project cultivation in the field of prefabricated buildings; In 2020, the "Nanjing prefabricated Building Information Service and Supervision Platform" established by Nanjing based on BIM will be put into operation. According to reports, the platform realizes the interaction and cooperation of data information of PC (precast concrete) components from design, production to construction, and realizes the information exchange, information sharing, whole process trajectory tracking and quality supervision of the whole industry chain; Through the use of two-dimensional code, Internet of things and other technologies, it can track the dynamics of PC components in real time, and provide support for the quality supervision and index control of government departments and data statistical analysis; In addition, the big data of the "platform" can also serve the progress management of engineering projects, planning arrangements, and production scheduling of production enterprises.

Entering the above information service and supervision platform, you can see the basic situation of all the projects under construction in Nanjing. Query the project with the prefabricated building index, you can understand the transfer time of the land, the type of the area, the content of the transfer conditions involving the prefabricated building, etc. The project information column is divided into prefabricated construction projects, only three board construction projects and other construction projects. For prefabricated construction projects, the platform can view the progress of components in real time, and can be detailed to a certain building and a certain floor; Whether a component is in the production phase, in the acceptance phase, or has been installed can be viewed in real time.

With this platform, the expert demonstration of construction projects can be completed online, such as applying for pre-sale permits, inviting tenders, and adjusting indicators. The enterprise first upload the relevant certification materials and documents as required, and the background staff will timely send the materials to the various review experts, and then the experts will issue the argumentation opinions or suggestions whether passed after joint discussion at the demonstration meeting, and realize the paperless office and information management in the whole process. In addition, there are three columns on the platform: demonstration library, directory library and Red and black list, which can easily find the complete list of various types of enterprises and their qualifications. At present, the Red and black list has also had a preliminary function - the background automatically generates the Top20 list of various types of enterprises according to the projects the enterprise has participated in before. With this platform, it can be more convenient to share information between functional departments related to prefabricated buildings, and it is also easier to supervise.

In order to do a good job in the service work, the industry office also specially printed a "business card", which in addition to the address and contact information of the industry office, is eye-catching two two-dimensional codes: one is the two-dimensional code of the above platform, and the other is the two-dimensional code of the QQ group of the Nanjing prefabricated building supervision platform. At present, the QQ group has nearly 1,300 members, mainly from Nanjing and surrounding cities. In recent years, the Industrial Office has also printed a series of brochures titled "Nanjing Construction Industry Modernization", including special issues such as parts production base, BIM technology application, prefabricated building typical projects, etc., detailing the information of relevant enterprises and attaching contact information to facilitate exchanges and cooperation between enterprises.

At the end of the discussion, Xu Hongfang also mentioned that the development of prefabricated buildings should scientifically handle the relationship between the government and the market. "In the early stage of the promotion of prefabricated buildings, the main responsibility of the competent government departments is to guide the project landing and do a good job of supervision, and the relevant supporting industries should give full play to the decisive role of the market in the allocation of resources, allowing its free competition; When the overall promotion to a certain extent, then play the role of government guidance, so that the relationship between supply and demand to find a balance, promote the sustainable and healthy development of prefabricated buildings."

At present, on the basis of summarizing and sorting out the "13th Five-Year Plan" prefabricated building development experience, in accordance with the overall requirements of new building industrialization, Nanjing has put forward the overall goal of the modernization development of the construction industry during the "14th Five-Year Plan" period: In 2021, the total area of newly started prefabricated construction projects in the city will account for more than 40% of the new construction area, and the delivery proportion of fully renovated residential buildings will reach more than 50%; After the increase of 5 percentage points year by year, by the end of 2025, the total area of new prefabricated construction projects in the city accounted for more than 60% of the new construction area, and the delivery proportion of fully renovated residential buildings reached more than 70%. At the same time, new innovative initiatives will be explored in smart construction and industrialization of new buildings.