Keywords

1 Introduction

As an important part of modern industry and urban development, architecture and related industries are crucial to urban sustainable development during planning, design, production, construction, use and maintenance.

Prefabricated buildings have the advantages of modular design, prefabricated materials, assembled construction, and industrialization, which is in line with the development direction of the construction industry, and in line with the concept of urban sustainable development [1]. Promoting prefabricated buildings has become a consensus of urban sustainable development. The impact of prefabricated buildings on urban sustainable development from both qualitative and quantitative aspects is tried to be explored in the paper.

2 Characteristics of Sustainable Development of Prefabricated Buildings

2.1 Characteristics in Planning and Design Stage

Prefabricated buildings that can reduce environmental load and improves industry efficiency have been accepted gradually [2]. From the stage of planning and design, the concept of sustainability is emphasized for prefabricated buildings, such as standardization design, assembly integration and low-carbon strategies, to promote urban sustainable development [3].

2.2 Characteristics in Construction and Operation Stage

Economic Development

  1. 1)

    High prefabrication rate and assembly ratio of prefabricated buildings can improve the production efficiency and drive industrial upgrading and technological progress, improve the overall level and quality of urban economic development [4].

  2. 2)

    Low labor intensity and short construction period cause improvement of construction quality and benefit.

Environmental Protection

  1. 1)

    Prefabricated buildings mainly have energy saving measures such as exterior wall maintenance structure, efficient energy use and renewable energy.

  2. 2)

    Types of water-saving measures, including water-saving appliances, non-traditional water sources, and water-saving sprinkler irrigation technology, can effectively reduce urban sewage discharge.

  3. 3)

    The functional space of prefabricated buildings is compact and the design is optimized, which can achieve the purpose of improving the utilization rate of land.

  4. 4)

    The prefabricated construction site is mainly operated by dry process, which produces less construction waste and less environmental pollution.

Social Benefit

  1. 1)

    Prefabricated buildings pay attention to the unity of construction and urban surrounding environment, can create activity space, achieve organic integration with urban space and improve the living environment.

  2. 2)

    Prefabricated buildings introduce new development concepts, such as intelligent construction, to solve outstanding problems such as assist in improving urban supporting functions and building sustainable society [5].

3 Influence Mechanism of Prefabricated Buildings on Urban Sustainable Development

Prefabricated buildings involve many aspects such as the progress of buildings and related industries, the increase of resource recycling rate, the upgradation of residents’ livability, and economic development [6]. Prefabricated buildings have different degrees of impact on urban sustainable development from three aspects of economy, environment and society, as shown in Fig. 1.

Fig. 1.
figure 1

The Influence mechanism of prefabricated buildings on urban sustainable development

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4 Evaluation Model of Prefabricated Buildings Impact on Urban Sustainable Development

4.1 Prefabricated Buildings Development Level Index System

When determining the evaluation index of the development state of prefabricated buildings, the factors such as policy, economy and technology should be mainly considered to achieve wide coverage and high accuracy. Literature research, expert questionnaires and AHP method are used to determine the index weights [7,8,9], finally form prefabricated buildings development level index system, including 8 one-level indicators and 30 two-level indicators, as shown in Table 1.

$$ {\text{S}}_{{\text{k}}} = \sum\limits_{i = 1}^{{}} {{\text{A}}_{i} } \cdot \delta_{i} = \sum\limits_{i = 1,j = 1} {B_{ij} \cdot } \theta_{ij} $$
(1)

where, \({S}_{k}\) is the development level of prefabricated buildings, and \(\text{k}\) represents different cities.

Table 1. Prefabricated buildings development level index system
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As in Table 1, Policies and regulations \({A}_{1}\), production and operation \({A}_{8}\), and market environment \({A}_{2}\) among 8 one-level indicators have the greatest impact on the development level of prefabricated buildings. It is because prefabricated buildings are still in the initial stage of development, which largely depends on the government industrial policy support, and local market, production and operation environment.

4.2 Evaluation of Urban Sustainable Development Level

The key to scientifically evaluate the level of urban sustainable development is to build comprehensive evaluation index system covering economic, environmental and social aspects [10], as shown in Table 2. The evaluation model includes 3 first-level and 19 s-level indicators, then adopts AHP and entropy method to determine the weight of each indicator. The weight calculation formula is shown below.

$${\omega }_{i}=a{\omega }_{oi}+(1-a){\omega }_{si}$$
(2)

where, \(\text{a}\in (\text{0,1})\), \({\upomega }_{\text{oi}}\) and \({\upomega }_{\text{si}}\) is the weight value assigned to entropy and AHP, \({\upomega }_{\text{i}}\) is the weight value obtained by weighted calculation, and \(\text{i}\) is the index number.

Table 2. Evaluation of urban sustainable development level
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4.3 Evaluation Model and Empirical Study

In Table 1, the development of prefabricated buildings mainly can be characterized by 8 first-level indicators. If the correlation between the 8 first-level indicators and the level of urban sustainable development can be derived and analyzed, then the impact of prefabricated buildings on urban sustainable development can be judged.

The multivariate linear function regression equation is used to study the correlation between dependent variables and multiple independent variables, shown as follows:

$$ {\text{T}}_{{\text{k}}} = \alpha_{0} + \alpha_{1} A_{1} + \alpha_{2} A_{2} + \cdot \cdot \cdot + \alpha_{n} A_{n} $$
(3)

where, \({\alpha }_{0}\) is a constant.

SPSS software was used to linear regression analysis of the data, and the independent variables were processed without dimension. The model fitting results were confirmed in Table 3. \({R}^{2}=0.964\)，indicates that the linear relationship between independent variables and dependent variables is close. The Durbin-Watson coefficient is 1.479, which indicates that the fitting effect is good.

Table 3. Model Summary
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The significance analysis is shown in Table 4, and the significance P = 0.002 < 0.05 indicates that the model has significant statistical significance and is effective.

Table 4. Model Significance Analysis
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Considering the excessive similarity caused by insufficient samples and limited data, the improved least squares estimation method is further used to solve the regression coefficient, and the calculation formula is as follows:

$$\beta ={({A}^{T}A+kI)}^{-1}{A}^{T}T$$
(4)

where, k is the regression coefficient, which can be determined when the estimated value of the regression coefficient of each explanatory variable in the model is basically relatively stable. Through SPSS software, \(\text{k}\) is set in the interval of [0,1] with search step size 0.01 for analysis, all variable coefficients will gradually stabilize with the increase of k value. k = 0.2 was selected for regression analysis, and the model \({R}^{2}=0.975\) was obtained, the independent variables and dependent variables were well fitted, F = 12.42, P = 0.01＜0.05, and the significance was good, which once again proved that the model was effective.

The influence formula of independent variable on dependent variable (Formula 5) can be obtained according to regression parameter analysis, and Formula 6 can be obtained by combining Formula 1 and the data in Table 1, therefore, evaluation model can be obtained by combining Formula 5 and Formula 6 listed below.

$$ {\text{T}}_{k} = - 2.478 + 0.048A_{1} + 0.029{\text{A}}_{2} + 0.243A_{3} + 0.007{\text{A}}_{4} + 0.089A_{5} + 0.003{\text{A}}_{6} + 0.002A_{7} + 0.389{\text{A}}_{8} $$
(5)
$$ {\text{S}}_{k} = 0.205A_{1} + 0.152{\text{A}}_{2} + 0.114A_{3} + 0.103{\text{A}}_{4} + 0.095A_{5} + 0.089{\text{A}}_{6} + 0.088A_{7} + 0.154{\text{A}}_{8}^{{}} $$
(6)

Through above evaluation model, it can be found that the development of prefabricated buildings has a positive impact on urban sustainable development mainly by promoting production and operation, economic environment, manufacture and transportation, design and other indicators. The reason may be that China is still in the stage of rapid urbanization development. With the support of the policy, prefabricated buildings are entering a period of rapid development and innovation, and there is significant great progress and visible fast development in the production and operation environment, intuitive economic output, production technology and design means of prefabricated buildings, so as to promote the overall urban sustainable development level.

5 Conclusion

Prefabricated buildings have the advantages of modular design, prefabricated materials and assembled construction, making it easy for the construction industry to achieve industrialization, automation, and high efficiency. The influence mechanism of prefabricated buildings on urban sustainable development is qualitatively analyzed in theory. Prefabricated building development level index system and the evaluation system of urban sustainable development level is both established, then the evaluation model and empirical analysis is performed by linear regression analysis of the correlation between above two systems, which provides a reference for guiding the further development of prefabricated buildings and formulating policies for urban sustainable development.