• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.2
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• pp.97-111
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• 2012

This study aims to find a proper construction cost calculation method by comparing unit prices of cost estimate in landscape construction among other public ordering construction projects. There were 7 out of 12 items from the actual work cost in the first half of 2011 were compared. The 12 items were classified as landscape Architectural construction and the 7 items were the approximate standard. As applied construction types, the comparable 35 items out of the 80 actual work cost items applied to 5 sites were compared to the unit price of the standard quantity per unit in March 2011, which was the approximate standard. Actual construction rate of the 7 items in the category of landscape sector was 104.86% for each item and 92.09% as a total construction cost. The high actual construction rate was caused by the high rate of seed spray depending on the status of applying rocks. However, there were more fundamental reasons for the cost generated from aslope treatment for grass and seed spray. So, it requires more detailed regulations on the modification factors for each soil type, the standard and needs to improve theillogical standard quantity per unit system. Actual construction rate of the 35 items in the applied sectors of civil engineering and architecture was 78.65% for each item and 71.31% (70.17%) as a total construction cost. This shows that actual unit cost cannot reflect actual cost structurally and standard quantity per unit system lacks practicality in terms of construction due to thelabor force. 85.1~91.2 % actual construction rate announced by the Ministry of Land and Maritime Affairs referred to the newly switched items. So the result was estimated as actual construction rate. This requires supplementation after verification in order to make the actual work cost produce at a proper rate. Also, standard quantity per unit system needs complementation with these actual data and so on.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.227-228
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• 2022

In order to achieve the goal of cost management, which is one of the three major management goals of building production, this paper introduces an approximate cost estimating automation technology in the design stage as the importance of predicting construction costs increases. BIM is used for accurate estimating, and the quantity of structural members and finishing materials is calculated by creating a 3D model of the actual building. However, only 2D basic design drawings are provided when making an estimating. Therefore, for accurate quantity calculation, digitization of 2D drawings is required. Therefore, this research calculates the quantity of concrete structural members by calculating the area for the recognition area through 2D drawing recognition technology incorporating computer vision. It is judged that the development technology of this research can be used as an important decision-making tool when predicting the construction cost in the design stage. In addition, it is expected that 3D modeling automation and 3D structural analysis will be possible through the digitization of 2D drawings.

• Korean Journal of Construction Engineering and Management
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• v.22 no.2
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• pp.42-52
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• 2021

The cost of remodeling parking lots of apartment houses accounts for about 20 percent of the total cost of remodeling. This means that when the remodeling cost of the underground parking lot is known, it becomes possible to estimate the total construction cost. The standard of estimation referenced when calculating the construction cost is difficult to apply to calculating the remodeling cost. Thus, a construction cost estimation model that reflects the characteristics of remodeling construction is necessary. This study developed a basic construction cost estimation model for expansion remodeling of underground parking lots of apartment houses that calculates the approximate cost of construction by reflecting the characteristics and design elements of remodeling. Based on literature review and consultation with experts, 37 activities of underground parking lot remodeling construction were derived. In order to enable calculation of approximate construction cost before the remodeling design drawing is finalized, the quantity calculation formula and unit price for each activity were presented. Based on expert advice, 13 factors that affect the increase in construction cost and weights of each factor were determined. As a result of applying three cases of remodeling complexes to the basic cost estimation model, the accuracy was confirmed to be 93 percent on average.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.604-605
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• 2015

To secure quality of dam construction needs appropriate construction duration. Tight construction schedule may have negative influence on infrastructure quality, work safety and maintenance cost. It is necessary to reflect proper construction duration in the planning phase. There have been standards for estimating construction duration of building and industrial complex development but dam construction have not. In order to estimate construction duration of CFRD, feasible study reports and design reports were analyzed to acquire available information. After that, considering on construction duration methods such as comparison with similar cases, approximate estimating formula, approximate quantity assumption were adapted to Critical Path items. Hence, this study present framework for construction duration estimating of CFRD in the planning phase. This framework can be applied other types of dam along the same line.

• Industrial Engineering and Management Systems
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• v.4 no.2
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• pp.123-128
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• 2005

The author derives a general explicit formula and presents an heuristic algorithm for solving Baker’s model. The examples show that this new approximate solution procedure for determining near optimum inspection intervals is more accurate than the ones suggested by Chung (1993) and Vaurio (1994), and is more efficient computationally than the one suggested by Hariga (1996). The construction and solution of the simplest profit model for an exponential failure distribution were presented in Baker (1990), and approximate analytical results were obtained by Chung (1993) and Vaurio (1994). The author will therefore mainly devote the following discussion to the problem of further approximating optimum inspection intervals.

• Journal of the Korea Institute of Building Construction
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• v.10 no.2
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• pp.75-80
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• 2010

With the intensifying of price competition and structural diversifications, the uncertainty of the domestic housing market has been increased. This highlights the importance of the planning stage of construction projects, and the increased need for a higher level of accuracy in approximate estimates. Currently, a number of research and development programs to calculate construction cost at the initial planning stage are being conducted. However, there are few cases in which local characteristics are considered in deriving the results. If local calibration can be conducted during estimates, more accurate cost estimates will be enabled. This could also play a major role in ensuring the success of a project. Therefore, the purpose of this research is to develop a calculation methodology and a model for a local index based on the historical data of public apartment buildings, and to derive a local index that supports accurate construction cost estimates.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1693-1705
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• 2013

To restore old aqueduct in Korea which is a irrigation bridge to supply water in paddy field area, it is needed to estimate approximate costs of restoration because the basic design for estimation of construction costs is often ruled out in current system. In this paper, estimating models of construction costs were developed on the basis of performance data for restoration of RC aqueduct bridges since 2003. The regression analysis (RA) model and case-based reasoning (CBR) model for the estimation of construction costs were developed respectively. Error rate of simple RA model was lower than that of multiple RA model. CBR model using genetic algorithm (GA) has been applied in the estimation of construction costs. In the model three factors like attribute weight, attribute deviation and rank of case similarity were optimized. Especially, error rate of estimated construction costs decreased since limit ranges of the attribute weights were applied. The results showed that error rates between RA model and CBR models were inconsiderable statistically. It is expected that the proposed estimating method of approximate costs of aqueduct restoration will be utilized to support quick decision making in phased rehabilitation project.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1474-1480
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• 2013

This study attempted to estimate construction costs in accordance with the resource-based cost estimation (unit cost price) system by diameter for TBM method, and analyzed the direct cost and the total cost. Based on such figures, this study performed a regression analysis and proposed a model for an equation for estimating construction costs. model for the resource-based cost estimation (unit cost price) system classified by diameter for TBM method proposed by this study can be effectively applied to business planning, preliminary investigation, feasibility study, construction cost estimations in the early design stages.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.139-140
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• 2012

Facility Management (FM) is a project phase to maintenance and to increase the qualities of product which is planned on the design phase and ensured on the construction phase. In addition, since the approximate time occupied in operation and maintenance phase is the longest from construction project as total approximate cost is about 85% of whole the project, it could be managed and realized primarily. The information of facility is not created on the specific point of project, but it might be created on the whole process of subject project widely. Thus, as the information could not be lost and it can be delivered into computer aided facility management system, it is necessary to manage the facility information. This paper proposed the necessities and the problems of BIM-based data interoperability on the Korean construction projects.

• Korean Journal of Construction Engineering and Management
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• v.21 no.3
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• pp.48-56
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• 2020

Prediction of construction cost in the planning stage that provides basic information for feasibility study, budgeting, and planning is an important factor for successful project execution. In this study, a prediction model was developed for the purpose of improving the accuracy of estimating the construction cost of Hanok in the planning stage. The cost of this model is estimated by two methods. First, the cost of wood work, which accounts for the largest portion of the total construction cost, is estimated by calculating the approximate quantity under various conditions (structure type, roof type, plane type, etc.). Second, the cost of the rest work sections except the wood work is estimated by using the unit cost model. The predictive model was verified by two case projects, and the error rate of total construction cost was -4%(case 1) and -6%(case 2). These results showed an error rate in the range that can be applied to practice in the planning stage.