Keywords

1 Introduction

The renovation industry is very competitive around the world, especially in China. Numerous projects are being renewed each year, a large part of which is hotel renewal projects [1]. Renewal is slower in hotel renovation projects due to a variety of factors (such as site, environment and lacking of drawings) [2]. The increasing demand on a comfortable and artistic living environment has led to hotels being renovated every few years, and hotel renovations are required to be completed with shorter durations than ever before for the sake of cost effectiveness.

In hotel renovation projects, many old hotels may have lost the original design drawings or the specific geometric information dimensions of the building due to management confusion, construction deviations or unclear changes [3, 4]. It will take a lot of time, money and work to renew projects without actual geometric data of the building. If renovation projects are guided by inconsistent and inaccurate original design drawings, it can incur a lot of rework. During the renewal process, the traditional on-site wet construction has the shortcomings of low efficiency, much waste and long construction duration, which often delays the construction duration and brings poor decoration quality [5].

Losting the original design drawings or the specific geometric information dimensions of the building is the biggest stinker in the hotel renovation projects. 3D scanning is a technique for quickly and massively capturing spatial point cloud data to build a three-dimensional model. 3D scanning allows to record the changes in as-built conditions and to ensure the accuracy of BIM model at operation stage. The prefabricated technology is a production method in which the components are prefabricated by industrial production lines, and then transported to the construction site for assembling [6]. The combination of 3D scanning, BIM and PC (Precast Concrete) is currently the most advanced digital solution in the construction industry [7]. The 3D scanning transforms the building into BIM model, and BIM can further optimize the decoration assembly. Combination of the three tools has been demonstrated good properties embodiment.

Hotel decoration projects have characteristics different from other renovation projects: similar decoration style across rooms. Once the decorating design is determined, it can be applied to all or most rooms. This paper proposes a BIM-based digital framework to shorten the renovation duration, save costs and reduce rework. The developed framework integrates building information modeling (BIM), 3D scanning and prefabrication technology to improve information utilization and reduce rework in hotel renovation projects.

2 Literature Review

2.1 Rework Problem

Rework is a significant challenge in project-based and labor-intensive construction industries [8]. Non-value-added reworks result in high costs and may lead to project delays that severely affect the project performance [9, 10]. Uncertainty caused by missing documents, inaccurate or conflicting information in original design drawings may result in rework. 3D laser scanning technology can provide a solution. Advanced laser scanning technology collects spatial coordinates of existing buildings to be refurbished and accurately restores original building information into BIM models [11,12,13]. Based on the rebuilt digital model, further design and prefabricated data analysis can be performed [14]. The BIM digital models can be used for facility management of property companies.

2.2 BIM and Prefabrication Integration

Numerous projects are being renewed each year. Prefabrication is an innovative solution in the decration industry that adopts the principles of industrialization [15]. According to the literature review, prefabrication has lower cost and better quality than traditional on-site construction [16].

BIM has great potential to support space standardization and flexibility for refurbishment or new buildings [17]. Building Information Modeling (BIM) is a tool of utilizing digital building information for effective information sharing. The integration of BIM and prefabrication is a possible way of improving the efficiency of collaboration in decration industry [18]. BIM can model prefabricated components for efficient data management [19]. BIM modularity and parametric advantages allow the optimized design of prefabrication components [20], promotion of information sharing and communication of prefabricated products, and help manage the progress of on-site assembly. The combination of BIM and fabricated technology is already the most advanced industry practices.

3 A Digital Framework for Hotel Renovation Projects

This framework integrates BIM, 3D laser scanning technology and prefabricated technology. Moreover, MBS (Model Breakdown Structure) and other technologies are used to support the proposed framework. The framework covers the design phase, procurement phase and construction phase of hotel renovation projects, as shown in Fig. 1. Reverse engineering based on 3D laser scanning is the data foundation of the entire framework. Prefabricated technology overcomes the shortcomings of construction waste on site and improves decoration efficiency. Construction stringing and parallel construction based on BIM model improve the decoration precision and construction efficiency.

Fig. 1
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BIM based digital framework for Hotel Renovation projects

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3.1 Design Phase

In real world projects, there are many inconsistencies between the original construction drawings and the final buildings, which are caused by poor construction quality, construction deviation or uninformed design changes. If a BIM model is built on the basis of original drawings, the decorative components produced accordingly will have large deviations resulting in difficult on-site assembly. The inconsistency can cause a lot of reworks. On-site 3D laser scanning can acquire 3D coordinates and spatial point information of the target object surface with high resolution and high efficiency. The accurate point cloud data collected by 3D scanning can facilitate the hotel BIM modeling. High-precision 3D laser scanning modeling solves the large error in actual construction and drawing.

Reverse modeling is one of the support technologies for hotel renewal projects. Point cloud data can be used to collect accurate spatial locations of components, providing data for later location analysis. Based on the BIM model constructed by the on-site point cloud model, the structures, electromechanical and decorative systems are virtually constructed on the same coordination platform. Through collision check, the electromechanical equipment layout is repeatedly simulated and optimized. The optimized piping arrangement ensures the clearance height and avoids unnecessary removal.

MBS is a decomposition tool similar to WBS, which classifies model elements [4]. It summarizes and defines the model scope with each submodel representing a more detailed definition of the model. MBS decomposes the design model in detail and can be defined to the bottom level such as screws. On the one hand, the decomposed components are exported as a BOM list to guide the prefabrication. On the other hand, each part that has been decomposed is made into a construction specification, and the construction tasks are visually animated for on-site workers.

3.2 Procurement Phase

The integration of BIM and digital manufacturing can enhance data interoperability. A single data source can eliminate the inconsistency introduced by multiple data sources and ensure the authority of design data.

As an important data foundation of the integrated system, the BOM list covers the material design, structure and process flow of the engineering design stage, planning stage, manufacturing stage, etc. At the same time, BOM is also the interface of Product Data Management (PDM) and Enterprise Resource Planning (ERP) system, and is designed and manufactured throughout the product. The process played an extremely important role.

3.3 Construction Phase

The 3D laser scan restores the specific dimensions and precise location of the building components. The BIM model built on the scanned data could export data to the manufacturing machine, which ensures that the manufactured components can be assembled without error on site. Based on the decoration BIM model, the total station can be used to achieve accurate on-site positioning, which can improve accuracy and efficiency. At the same time, based on the release file, the production cycle is scientifically arranged.

In manufacturing, MBD (Model Based Definition) was applied to realize digital manufacturing and on-site installation, which changed the traditional linear construction process. The MBD single data source can eliminate the inconsistency of multiple data sources, ensure the accuracy of design data, and improve data security. The single data source is used throughout the project by BIM, and each stakeholder can perform parallel construction work according to the BIM model, which can effectively control the construction progress.

4 Case Study

4.1 Background of Case Study

To explore how the proposed framework could be applied in renovation projects, this study took a holiday hotel project as an example. The project was a commercial hotel under renovation. The difficulties facing the project team were: (1) the schedule of design, procurement, and construction was tight; (2) The construction site space was limited and the decorative material stacking area was very small; (3) the investment budget was tight. The Holiday hotel rooms were divided into three types and each type had the same number of rooms. The decoration design had a strong coupling with the electromechanical system. In order to solve the above problems, the BIM-based digital framework route is applied to the hotel interior decoration life cycle (design, construction, completion, operation and maintenance phase).

4.2 Application at the Design Phase

With the proposed digital framework, information was well shared throughout the project lifecycle and the project progress was effectively controlled. At the design phase, 3D scanning was used to collect point cloud data for the holiday hotel. In this study, a Trimble TX5 3D laser scanner was used. With high-speed laser scanning, designers can quickly access the 3D data of the target building to quickly build a 3D point cloud model. Figure 2 shows the scene of the scanning scene and the point cloud model obtained by scanning. Compared with traditional measurement methods, a lot of measurement and inspection time, and labor cost at the design phase were saved. According to the BIM model built upon the point cloud data, the structures, electromechanical and decorative systems were virtually constructed on the same platform, and the arrangement of electromechanical equipment was optimized through collision checking. The optimized pipeline arrangement ensures clearance height; avoids later demolition and shortens the construction period.

Fig. 2
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Hotel room point cloud model

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4.3 Application at the Procurement Phase

At the procurement phase, the model was decomposed using the Model Breakdown Structure (MBS) method based on the BIM model, and the components were further categorized to extract the size, material, position and other information required for manufacturing from the BIM model, and the BOM was derived.

As shown in Fig. 3, the bathtub area was decomposed into smaller modules by MBS. The modules can extract information such as the size, material, and position required for the machining operation. The BOM list contained the material name, specifications, usage, process and attributes to guide the production process (see Fig. 4).

Fig. 3
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Bath area MBS decomposition

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Fig. 4
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BOM list of water supply and sewer system

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The SolidWorks model was imported into the CNC processing equipment by converting it into a STEP or IGS file format. The Manufacturing Execution System (MES) system converted the component order of the ERP system into a manufacturing order, collected the production information in the manufacturing process, and used the collected data for management. The MES system applied the collected data for management, scheduling, production, control, and input feedback to the ERP system. Based on a BIM model, Fig. 5 showed the process of cutting and installing a metal component with a numerical control device.

Fig. 5
figure 5

Metal component processing and installation

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4.4 Application at the Construction Phase

Based on the decoration BIM model, pay-off robot was used to achieve accurate on-site positioning (see Fig. 6). Since the model already contains accurate building dimensions, the determination of the construction point based on the BIM model is accurate.

Fig. 6
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On-site positioning

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The BIM data package served as a single data source for the entire renovation project. In the project, the component production and the release of the construction site can be guided at the same time. As shown in Fig. 7, the on-site pay-off and pre-fabricated components of the processing plant can be carried out simultaneously, and the components can be accurately installed. Parallel construction greatly shortens the construction time and the entire construction period is better controlled.

Fig. 7
figure 7

Parallel construction process based on BIM

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5 Results and Discussion

After comparison it was found that there are many inconsistencies between the actual building and the original design drawings. At the joint position of the structural beam and the wall on both sides of the room, the entire structural frame is offset to the west side, and the actual cross section of the east side beam is larger than 5 cm than the design drawing. Figure 8 showed the point cloud data model and point cloud entity model of the project.

Fig. 8
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Point cloud entity model

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Based on the size provided by the point cloud data, a BIM decoration model of a single room was constructed as shown in Fig. 9.

Fig. 9
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Single room BIM decoration model

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In this project, the layout was so complicate that there were many collisions. Through BIM design, the plan had a net height of 2.5 m in front of the pipe gallery and a net height of 3.5 m in the power distribution room. After optimization, the net height of the pipe gallery was 3 m, and the power distribution room was clean. Figure 10 showed the layout of the electromechanical equipment before and after the optimization.

Fig. 10
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Mechanical equipment arrangement before and after optimization

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Compared with similar projects in the past, it can be concluded that the digital framework reduced the project total construction time by 15%, the total procurement schedule by 25%, the cost estimation time by 50%, the design changes by 30%, and project management costs by 40%.

6 Conclusion

This study proposed a new framework to improve the efficiency in hotel renovation projects. An investigation into the inefficient construction process revealed that a large amount of reworks were caused by the inconsistency between the building and the drawings. The primary solution was to combine BIM, 3D scanning and prefabrication technology, which enhance information sharing across the project lifecycle. Besides, the applicability of this proposed framework was tested and validated in a case study of a Holiday Hotel.

  1. 1.

    The combination of BIM, 3D scanning and prefabrication improved the information utilization among all the professionals at different phases. The proposed framework had the following practical values:

  2. 2.

    Compared with traditional hotel renewal projects, the decoration quality has been greatly improved. The deviations of prefabricated components produced in factories are controlled at the level of millimeters.

  3. 3.

    The construction period has been greatly shortened. Efficient digital manufacturing reduces work time. In addition, BIM improves collaboration and enables professionals to accurately understand and share building information.

  4. 4.

    The economic benefits have been significantly improved. In this case, project management costs were saved by 40%.