• Journal of the Korean Society of Safety
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• v.37 no.3
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• pp.34-44
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• 2022

This study analyzed the smart construction safety cost included in safety management plans that are approved before construction. Specifically, it refers to the cost incurred in constructing and operating a safety management system using wireless communication and facilities. Based on the obtained statistical results, an activation policy for the inclusion of the smart construction safety cost in building safety management plans was proposed. The smart construction safety cost must be included in the safety management cost; notably, this is mandated by the Construction Technology Promotion Act. However, there are some problems with the inclusion of smart construction safety costs. To analyze the problems encountered when calculating the smart construction safety cost and including it in safety management plans, in this study, statistical analysis was performed using the data of 1,334 safety management plans received at the Construction Safety Management Integrated Information (CSI) from June to August 2021. The results show that only 50.7% of the safety management plans included the smart construction safety cost although the current law mandates 100% inclusion of these costs. Thus, it is apparent that the smart construction safety costs are only included in a low proportion of sites. In addition, the calculated smart construction safety costs were shown to have a small correlation with the construction cost; moreover, they appeared to be distributed at a constant cost level. In this context, it is believed that perfunctory cost calculations were performed at most sites since the effect of the construction cost on the smart construction safety cost was negligible. Therefore, it is necessary to improve the inclusion of smart construction safety costs by strengthening the authorization process of the approval institute of safety management plans. In addition, institutional support, such as guidelines that promote the calculation and inclusion of appropriate smart construction safety costs according to the characteristics of sites, are needed.

• Journal of the Korea Institute of Building Construction
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• v.10 no.4
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• pp.123-132
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• 2010

Rebar work accounts for approximately 30% of the total construction costs for rebars and concrete. Recently, the high rising prices of rebars have become one of the principle factors of rising construction costs. Therefore, construction companies are putting much effort into loss reduction of rebars. Consequently, in this study, we wished to present loss reduction methods of rebars before the preparation of the placing drawings. To devise such methods, we collected previous case studies and analyzed methods that were applied for loss reduction. As a result of the analysis, we were able to find the following methods for loss reduction of rebars: method of reducing the number of splices at the mat foundation, method of reducing splice length at the internal columns or walls of the underground parking lot, method of reducing cap-ties of internal beams of basement floors excluding perimeter beams, and method of reducing anchorage length at the internal column or wall of the underground parking lot. Based on those analysis results, we presented our own loss reduction methods of rebars. Applying our methods resulted in considerable loss reduction.

• Journal of the Korea Institute of Building Construction
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• v.9 no.1
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• pp.65-73
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• 2009

Looking at current construction costs estimations of publicly declared public works, there are many instances where estimation criteria are ambiguous and doesn't imply the reality. Up to date, estimation criteria for calculating construction cost estimations are simply by unit area multiplication and stochastic construction cost estimation. However, possibility of making errors are high due to using uniform data that excludes each public work's specifications and environmental conditions. Further, on the aspect of cost management, there is certain limitation in the efficiency of cost management in order-placing stage and commencing-work stage; while efficient cost management and reduction of expenses are highly possible during initial stages of the project. In this respect, the paper adopts positive approach with regards to construction cost estimations of public works and draws common elements from calculation tables of the construction cost estimations from 3 completed domestic construction works; after which, the paper analyzes whether business exposition, construction guide and publicly-declared estimated construction costs that the orderer issued are calculated economically and properly; deducing problems in the process, the paper seeks to recommend rational calculation method on this.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.579-585
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• 2009

Recently, Vertical-Closed Loop system using geothermal which is the most efficient among the building cooling and heating systems is coming into wide spread due to assistance of domestic policies. However, there is a limitation that a design of ground heat exchanger taking 60% of construction cost is done by GLD and GLHEPRO programs without specific guidelines and consideration on Entering Water Temperature(EWT). For getting an optimal EWT, we analyzed the costs for construction of ground heat exchanger and cooling and heating for 15 years. In the results, reduction of construction costs as the length of ground heat exchanger shortens was much greater than increase of the electrical power consumption as COP gets low. EWT that COP of heat pump can be 3.76 or above was below $31^{\circ}C$ in cooling and was over $5^{\circ}C$ in heating.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.3
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• pp.167-174
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• 2008

Cost related to building equipment accounts for about 85% of the life cycle cost of buildings. Therefore proper selection of air-conditioning system is important for reducing the overall cost of buildings. In this study, medium capacity EHP and GHP for air-conditioning a building with a floor area of 1,200 $m^2$ are compared economically. To consider all the factors of initial and operation costs effectively, an annual equal payment method is proposed. For the initial cost, cost of equipment, construction, installation, electric facility, financial subsidy and tax cut is considered. Cost of basic electricity, energy(electricity and gas), space charge, labor, insurance and repair is considered for the operation cost. Under the assumptions made in this study, overall cost of EHP is less than that of GHP, but this is not absolute and different outcome may result if different assumptions are made. This study is useful for those who are interested in choosing an air-conditioning system that costs less for mid-size buildings with simple calculations.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.7-10
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• 2008

As the land price in the downtown area increases, buildings are becoming bigger, deeper and higher. Consequently, the importance of underground construction has increased. Although construction engineers make every effort to complete underground construction without any problem, construction failures like landslides and the collapse of a retaining wall occur because of the uncertainty of the soil conditions as well as the unexpected risks of excavation work. In order to prevent potential excavation accidents, it is essential to understand the causes and impacts of such accidents. However, there are only a few examples of construction failures, which show the economic impact on accidents during excavation because of the sensibility of the information. This paper presents two cases of excavation accidents, which were investigated by construction insurance company. The compensation for the accidents paid by the insurance company was compared with the estimated costs calculated based on the estimation method for excavation accidents proposed by our previous study. The comparison results showed that the estimate calculated by our method was much less than the actual compensation because the estimate solely focused on the construction costs whereas the compensation included other external factors.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.294-295
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• 2018

Nowadays, the construction industry utilizes 3D models in the designing process, on which research is being conducted to establish an automated system for project cost estimation in connection with information related to construction such as material unit costs and wages, beyond the level of design interference review and construction quantity estimation. In this process, the project cost is estimated in connection with unit price data after takeoff the quantity based on the 3D model attributes and data types. A way to reduce cost and risk would be first developing prototypes of some of essential buildings and works, comparing and validating the outcomes, and then extending to the whole scope, because estimates differ on the basis of the scope and level of 3D design models as well as the data accuracy. This study analyzes case studies of project cost estimation by computing the quantity on the basis of 3D model in the construction industry and explores methodologies and management measures applicable for estimating nuclear power plant construction project costs.

• Journal of KIBIM
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• v.9 no.2
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• pp.1-10
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• 2019

In this research, schedule optimization is defined as balancing the number of workers while keeping the demand and needs of the project resources, creating the perfect schedule for each activity. Therefore, when one optimizes a schedule, multiple potentials of schedule changes are assessed to get an instant view of changes that avoid any over and under staffing while maximizing productivity levels for the available labor cost. Optimizing the number of workers in the scheduling process is not a simple task since it usually involves many different factors to be considered such as the development of quantity take-offs, cost estimating, scheduling, direct/indirect costs, and borrowing costs in cash flow while each factor affecting the others simultaneously. That is why the optimization process usually requires complex computational simulations/modeling. This research attempts to find an optimal selection of daily maximum workers in a project while considering the impacts of other factors at the same time through OPEN BIM based multiple computer simulations in resource leveling. This paper integrates several different processes such as quantity take-offs, cost estimating, and scheduling processes through computer aided simulations and prediction in generating/comparing different outcomes of each process. To achieve interoperability among different simulation processes, this research utilized data exchanges supported by building SMART-IFC effort in automating the data extraction and retrieval. Numerous computer simulations were run, which included necessary aspects of construction scheduling, to produce sufficient alternatives for a given project.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.321-322
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• 2021

This study is to develop a non-contact construction project management solution that can reduce cost and construction period through on-site information sharing, minimizing contact with others by COVID19, and improving the productivity of the construction industry. Decisions, checklists, and execution rates of construction costs can be checked with smart devices through sharing on-site photos and videos, exchanging opinions. Details and checklist data stored on cloud servers of sites that apply non-face-to-face construction project management solutions will be used as data for analyzing amounts and construction periods depending on the size of the construction. Real-time field information sharing will reduce expected problems and waste factors, expand communication channels with users to prevent or minimize construction disputes and claims, and contribute to the expansion and growth of new research industry markets in construction technology.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05b
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• pp.97-98
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• 2011

The number of high-rise buildings has increased year after year, with there currently being 5 projects in progress to construct buildings higher than 100 stories in Seoul alone. The construction cost for such high-rise buildings is significantly higher than the cost for a conventional low-rise building, while maintenance costs are expected to be two to three times higher. To reduce the maintenance cost of a high-rise building, there is the need for a guide rail to be used for maintenance, which is why there is the need for research on the guide rail system. For this reason, as preliminary research to develop a guide rail, this study aims to derive the factors increasing construction cost by taking the installation of a guide rail into account. This is expected to lay the groundwork for the design and construction of guide rails for high-rise building maintenance.