• Journal of KIBIM
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• v.7 no.2
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• pp.16-24
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• 2017

It is very important to estimate accurate construction total cost needed early in the project. In the initial phase of the design, the project cost estimates are determined by total quantity from design documents and the variables that affect the calculation of the total cost of the project. In order to determine accurate total construction cost, the contractor has to produce detailed quantity information based on the drawings and specifications. The process of preparing quantification and cost estimation documents is still being worked out manually, and a lot of errors have been occurred in many cases. Recent advances in information technology have led to the BIM based quantity takeoff and cost estimation. However, there are some limits to the extent to which the current specifications for BoQ documents are computed from BIM model. This research analyze the current BoQ cases and analyze how to make quantity takeoff possible through BIM. The study defined five levels of quantity category that could be produced by BIM. Only about 40% or indirectly usable items can be used when information is extracted to BIM modelling. This is very insufficient to fill out the BoQ. The BoQ document structure quantity takeoff specifications should be simplified in order to BIM based cost estimation more efficiently.

• Korean Journal of Computational Design and Engineering
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• v.20 no.4
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• pp.431-442
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• 2015

Currently, a BIM-based quantity takeoff (QTO) system is mainly focused on architectural projects. To perform this, diverse quantity takeoff methods such as an object-based automatic quantity takeoff, manual quantity and base functions of calculation have widely been utilizing. However, since BIM library for road projects includes structural elements associated with alignment, it is necessary to establish cost estimation system interlocked with historical cost using 3D library by each unit length. Accordingly, the aim of this study is to develop cost estimation model with using a historical cost approach so that it can be utilized in construction planning based on the BIM library for road projects. For this, based on the BIM library for road, the standardized quantity is estimated, and a process for calculating historical cost and a verification model with a 5D simulation was developed by mapping a WBS code with each BIM library object. This can be applied during the approximate cost estimation process in a project planning and an initial design phase for road projects. Besides, it is expected that these results will be utilized in constructing an optimal historical cost estimation process for project libraries.

• Journal of KIBIM
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• v.1 no.1
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• pp.13-17
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• 2011

Currently, a lot of design, engineering and construction companies has been interested in BIM(Building Information Modeling) technologies for higher productivity and efficiency. The information provided from BIM can be mostly used for automated quantity takeoff. But BIM has some problems for fully automated quantity takeoff to solve. The purpose of this study is to show the problems and suggest solutions through case study, especially with concrete and form work.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.92-93
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• 2019

Estimates based on BIM makes it possible to perform from quantity take-off to construction cost estimates by using model, which is made in the phase of design and construction. As the BIM models are made up of the units of element, there an advantage of the automative quantity take-off, if the correction or change of element occurs. Work items, not included in the elements of the BIM model, are excepted from bill of quantity. Level of detail(LoD) of the BIM model can be improved for detailed estimates, but an excessive modeling for estimates is inefficient. This study presents the measure for selection and quantity take-off of work items, those are not expressed in the BIM model. The proposed method avoids the creation of excessive BIM Models and enables quantity take-off in conjunction with the element.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.217-218
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• 2015

There are various standards and manuals on the quantity takeoff for construction estimation. However, a lot of time and money has been spent on retraining because of difference between practice and education. Therefore, the main purpose of this paper is to suggest improvement to analyze problems and limitations of the existing educational content for quantity takeoff. In order to achieve research objective, comparative analysis for quantity takeoff contents is carried out. This study will be extended to assist in effective quantity takeoff in building projects by supplementing the existing issues with quantity takeoff contents and developing a BIM-based quantity takeoff multimedia contents that use diverse media to increase the understanding on the subject for a non-professional.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.6
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• pp.567-576
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• 2017

The object of this research is an establishment of BIM-based quantity takeoff(QTO) and cost estimation guidelines for reinforcement concrete structures focused on improvement of field applicability in transition period from 2D drawing-based environment to 3D BIM-based environment. Preliminary studies on existing guidelines and standards for BIM modeling, QTO and cost estimation of reinforcement concrete structures are performed, and then a standardization of BIM-based cost estimation process is proposed through comparative analysis between 2D drawing-based cost estimation process and 3D BIM-based. In addition, modeling, QTO, and cost estimation processes of cost-BIM model for RC structures are conducted. The contributions of this research and the guidelines suggested by this research are 1) lowering barriers to entity to the new BIM-based environment for small size companies, 2) reducing construction cost by a close estimate, 3) establishing the foundation for integrated management of informations through construction project life cycle, 4) and ultimately, developing the BIM ecosystems.

• Korean Journal of Construction Engineering and Management
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• v.21 no.1
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• pp.61-69
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• 2020

As the amount of information generated in the construction project increases exponentially, design and construction review have a serious impact on the success of the site. For this reason, academic and business circles have been expanding the use of BIM at the whole life, and BIM is now accepted as one of the standards used in the construction industry. However, the BIM-based design for the temporary work is used as an aid to the 2D design because there is no specialized software and there is absolutely lack of a professional engineer. The objective of this research is to develop BIM-based temporary work support system. This system minimizes human errors in BIM-based design, quantity takeoff and inspection and shortens working hours.

• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.79-92
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• 2011

Quantity take-off is one of the critical tasks that determine the cost of a construction project, and its result should be accurate and reliable. BIM-based quantity take-off is a very attractive process for practitioners since the quantity take-off can be done automatically in a fast and accurate way. However, the result of BIM-based quantity take-off can be varied depending on how BIM was modeled. As a project progresses, more detailed design information is getting available, and it can be expected that the degree of completeness and accuracy for the BIMbased quantity take-off is going to be improved as well. However, when estimation is performed at each stage of a project life-cycle, there is no way to measure or forecast how accurate of the quantity take-off result from the BIM data given at the current stage. Therefore, this research derived factors that affect the BIM-based quantity takeoff and developed a methodology and framework to measure and forecast the completeness of BIM-based quantity take-off. The measurement framework and index that are proposed by this research was verified and validated for their consistency and feasibility through six pilot projects.

• Korean Journal of Computational Design and Engineering
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• v.18 no.2
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• pp.93-103
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• 2013

In the situation where there should be a gap between the design environments of 2D drawing and 3D BIM modeling, it is unavoidable aspect to face confusion caused by parallel usage of both technologies unless the project delivery systems are entirely upgraded to 3D. Therefore, it is critical to make efforts to minimize this confusion. Meanwhile, detailed drawings have very important roles in the construction process because they do not only concretely express construction methods for a given design plan but also provide basis for quantity takeoff and construction cost estimation etc. This paper suggests a plan to standardize detailed information based on BIM standard framework in order to make BIM realize the information. In the short term, this plan provides improved environment where both BIM and CAD technologies can be applied and, in the long term, it provides bases for BIM to replace CAD technology.

• Journal of KIBIM
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• v.10 no.4
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• pp.40-49
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• 2020

This report describes the development of a program that can be linked to an alignment and extracts related information using a prefab structured digital engineering model. The subject bridge was set as a straight alignment, the Superstructure type as Precast girder and the Substructure type as Precast pier and Cast-in-situ Abutment. We identified the variables required to create a digital engineering model and reviewed them to create the digital engineering model by entering them as numerical values in the program. In addition, it is configured so that the variables linked to the alignment can be entered numerically. The quantity takeoff can be calculated when the design is complete. The purpose of the program development presented in this report is to enable the designers to select the optimal alternative by designing a bridge that best fits their current situation, extracting the relevant information and then by providing it to the manufacturer and construction company.