Keywords

1 Introduction

Prefabricated building in foreign countries mainly from the beginning of the 20th century began to attract people’s attention, to the 1960s in the United Kingdom, France, the Soviet Union and other countries took the lead in the attempt to finally achieve [1]. Scholar Buncio believes that the current construction industry is facing colliding forces that make our current trajectory wasteful, inefficient and unsustainable, which requires us to move into the era of prefabricated and modular buildings [2]. As a pillar industry of the country, the steady and sustainable development of the construction industry is crucial to the progress of the whole country [3]. Experts predict that the total output value of prefabricated and modular buildings will reach $209 billion by the end of the decade, with huge development potential [4].

Since 2015, the new prefabricated construction area, construction industry scale, and industrial output value related to assembly have continued to rise, carrying out the process of urbanization at a high speed [5]. Zheng Minli believes that China’s prefabricated buildings are in a stage of steady advancement, continuous enhancement of the endogenous power of the industry, gradual establishment of the policy support system and preliminary establishment of the technical support system [6]. Zhao Likun believes that the prefabricated building has the greatest potential in southwest China, the development of prefabricated building in East China is relatively stable, and the development potential in South China is the least [7]. Li Qiangnian, Liu Xia et al. use the literature research method to draw a conclusion that the main constraints of prefabricated buildings in China are summarized in six aspects: technical factors, market environment factors, industrial organization factors, cost factors, policy factors and talent factors [8, 9].

There are many methods to evaluate the development potential of prefabricated buildings, and with the deepening of the research, the research methods have been developed from qualitative description to quantitative data analysis stage, interpretive structure model (ISM), analytic hierarchy process (AHP), fuzzy comprehensive evaluation method, SWOT analysis method, etc., are widely used in the development analysis of prefabricated buildings [10]. On the basis of previous studies, this paper constructs a comprehensive evaluation model of the development potential of prefabricated buildings by applying the principal component weighted TOPSIS evaluation method, and comprehensively evaluates the development potential of prefabricated buildings in the city.

2 Design of Development Potential Evaluation Index of Prefabricated Buildings

2.1 Design Principles of Index System

  • 1. Comprehensiveness. Based on relevant theories, the selected indicators will cover the main factors affecting the development potential of prefabricated buildings in the city.

  • 2. Simplicity. The complex problem is simplified, and the indicator system selected can reflect the development potential of prefabricated buildings in a concise and clear way.

  • 3. Scientific practicability. In the process of evaluation, the data of different regions or the data of the same region at different times can be comprehensively compared, and the whole index system can be used in the whole country.

  • 4. Maneuverability. The selected indicators have the corresponding data sources in different cities at different times, and the analysis data are from the official data released in various periods in various places, and the data sources are real and reliable.

2.2 Evaluation Index Design

According to the basic principles of index selection from the four aspects of economy, technology, policy and market, this paper selects the appropriate evaluation index and establishes the development potential evaluation system of prefabricated buildings.

Table 1. Comprehensive evaluation index system of development potential of prefabricated buildings
Full size table

3 Evaluation Model of the Development Potential of Prefabricated Buildings

3.1 Selection of Evaluation Methods

At present, the commonly used weighting methods are mainly divided into subjective weighting method, objective weighting method and combination weighting method. Subjective weighting is generally used in evaluations where data collection is difficult or information cannot be directly quantified. Objective weighting rule refers to a kind of method that obtains weights after analyzing and processing each index data by mathematical statistics, but the calculated results are greatly affected by the sample data. The combination weighting method refers to the recombination of the results calculated by the previous two methods. In the comprehensive evaluation index system established in this paper, each index can be quantified, so the objective weighting method is considered. In the objective weighting method, the principal component analysis method can simplify complex indicators and is more suitable for the comprehensive evaluation index system of the development potential of prefabricated buildings established in this paper, so the principal component analysis method is chosen.

3.2 Evaluation Steps of Weighted Principal Component TOPSIS Evaluation Model

  1. 1.

    Suppose a region is evaluated and ranked for its development potential of prefabricated buildings in m years, in which there are a second-level indicators and n third-level indicators under each classification index, then the original data matrix can be formed according to the characteristics of the indicators:

$$X{\text{a}} = \left( {\begin{array}{*{20}c} {x_{11} } & {x_{12} } & {...} & {x_{1n} } \\ {x_{21} } & {x_{22} } & {...} & {x_{2n} } \\ \vdots & \vdots & \vdots & \vdots \\ {x_{i1} } & {...} & {x_{ij} } & {...} \\ \vdots & \vdots & \vdots & \vdots \\ {x_{m1} } & {x_{m2} } & {...} & {x_{mn} } \\ \end{array} } \right)$$
(1)
  1. 2.

    The data in the original matrix are treated with the same trend and dimensionless to form a standard data matrix. And calculate the sample correlation coefficient matrix of the standardized matrix Za, namely:

$$R_{\text{a}} = ({r}_i{}_j )_{n \times n} = \frac{Z_a^T Z_a }{{m - 1}}$$
(2)
  1. 3.

    Determine the number P of principal components. Generally, the cumulative contribution rate of the principal component is greater than 85%, which means that the extracted principal component can contain more than 85% of the information of the original variable, namely:

$$\sum_{j = 1}^p {\frac{\lambda_j }{{\sum {_{j = 1}^n \lambda_j } }}} \ge 85\%$$
(3)
  1. 4.

    Calculate the Euclianian distance value between vij and positive and negative ideal solutions under the second-level index of item a in the comprehensive evaluation index system of prefabricated building development potential for each participating year or city, Namely:

$$S_{ai}^+ = \sqrt {{\sum_{j = 1}^p {(v_i{}_j - v_j^+ )^2 } }} (i = 1,2, \cdots ,m)$$
(4)
$$S_{ai}^- = \sqrt {{\sum_{j = 1}^p {(v_i{}_j - v_j^- )^2 } }} (i = 1,2, \cdots ,m)$$
(5)
  1. 5.

    Calculate the relative proximity of the secondary index of item a of the comprehensive evaluation index system for the development potential of prefabricated buildings in each participating year. Namely

$$S_{ai} = \frac{{S_{ai}^- }}{{S_{ai}^+ + S_{ai}^- }}(i = 1,2, \cdots ,m)(0 \le S_{ai} \le 1)$$
(6)
  1. 6.

    According to the relative proximity calculated by the above formula, the second index of item a in the comprehensive index system for the development potential of prefabricated buildings is sorted. The greater the value, the greater the development potential of prefabricated buildings in the year or in the region.

3.3 Evaluating the Results of Empirical Analysis of the Model

According to the above steps, based on the comprehensive evaluation index system of the development potential of prefabricated buildings in Table 1, the original data analysis results of the development potential of prefabricated buildings in several typical cities of Chongqing, Beijing, Guangdong, Henan, Sichuan, Liaoning and Hubei in 2021 are selected, as shown in Table 2.

Table 2. Comparison results of the overall market evaluation of the development potential of prefabricated buildings in Chong Qing, Beijing and other regions in 2021
Full size table

As can be seen from Table 2, Beijing has the greatest development potential for prefabricated buildings, followed by Sichuan, Guangdong, Liaoning, Chongqing, Henan and Hubei. Mainly, Beijing, as the first batch of demonstration cities of prefabricated buildings, has perfect government policies, synchronous market forces, and takes many measures to develop prefabricated buildings, and has good economic and technical conditions, a good market environment, and strict implementation of the whole process supervision, which promotes the high-quality implementation of prefabricated building projects. Other cities are mainly the policy of mandatory development measures, regulatory systems and other late release, resulting in the entire market backward development; Secondly, the development of technology is far behind Beijing, Guangzhou and other cities, and it is necessary to continue to work hard to achieve balanced development and catch up with the development pace of well-developed areas.

4 Conclusions

According to the evaluation results, on the basis of giving full play to their existing market and industrial advantages, each city can promote the vigorous development of local prefabricated buildings by establishing and improving the policy support system, researching and formulating local standards and norms, cultivating and supporting leading enterprises, building modern industrial clusters and a series of strong measures. However, at the same time, the technical standard system is not perfect, the overall and systematic design is missing, the coordinated development of the industrial chain is not deep enough, the level of intelligent construction is not high, and the publicity and promotion efforts are far from enough, which are more or less reflected in the process of the development of prefabricated buildings in each demonstration city. Entering the “Fourteenth Five-Year Plan” period, in the face of new situations, new tasks and new requirements, all localities still need to make continuous efforts, focus on key points, make up for weaknesses, strong and weak points, solid advantages, tap development potential, further innovate and optimize the development path, build a good industrial ecology, in order to better promote the continuous development of prefabricated buildings across the country. It can mainly start from the following aspects:

  • (1) Government guidance, market force, and multiple measures to develop prefabricated buildings.

  • (2) Take government investment projects as a breakthrough, and gradually increase the promotion of prefabricated buildings.

  • (3) According to local conditions, constantly improve the technical specifications and evaluation system of prefabricated buildings.

  • (4) Build a diversified incentive mechanism to fully stimulate the market vitality and mobilize the enthusiasm of enterprises.

  • (5) Vigorously cultivate the construction industry workers, to provide talent support for the development of prefabricated buildings.