• Korean Journal of Construction Engineering and Management
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• v.23 no.5
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• pp.65-76
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• 2022

The New Excellent Technology (NET) designation system, introduced in 1989 for the purpose of promoting the development of domestic construction technology and enhancing national competitiveness, reviews the statement of construction cost of new technologies. And the cost reduction effect such as design, construction, and maintenance cost and the effect of reducing the construction duration are evaluated as an evaluation criteria of economic feasibility. However, in this evaluation process, differences of opinion between the institution of construction cost estimating standard management and the new technology developer about unique technologies frequently occur. In addition it is difficult to objectively compare the construction duration with existing similar technologies because there is no information on productivity as the current cost estimating standards for new technologies only present the required amount per unit quantity. In this study, the current state of cost estimating criteria review procedure, evaluation criteria, and cost estimating standards establishment method were analyzed when screening for the designation of a new construction technologies, and compared with overseas cost estimating standards, measures to improve the cost estimating standards of current construction new technologies were suggested. Through the improved cost estimating standards of this study, it is expected that cost information on new technologies will be provided to clients in more detail than the current ones, and the availability and applicability of new construction technologies would be improved by simplifying the construction cost calculation process more.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6D
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• pp.829-837
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• 2011

Construction cost estimation in planning phase which calculates the cost for performing construction tasks is used for various ways. Meanwhile, in the case of road construction, the existing cost estimating method in early phase based on numerical mean value of the past is not accurate to be used. This paper propose neural network model for estimating road construction cost in planning phase to solve the limit of current cost estimating method. The model was designed using past road construction bidding records, and variables of model were optimized through trial and error. The estimation result of the model was compared with regression analysis and government's standard and it was verified that the model is better in accuracy. It is expected that the proposed model will be used for road cost estimation in planning phase.

• Journal of Korean Society of Steel Construction
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• v.22 no.1
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• pp.55-65
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• 2010

To effectively secure and execute the national budget, it is very important to estimate the reasonable construction cost of each process in the construction of public facilities and works. The construction cost is generally estimated at the time when the design of the targeted structures has been completed. Without detailed sectional drawings and with only simple information on bridge structures in the planning stage or in the early design stage. it would be very difficult to predict the approximate construction cost. In this study, a more efficient and appropriate approximate construction cost estimation model in the planning stage and in the early design stage is presented and verified as reliable by analyzing the construction cost data of 61 existing steel box girder bridges from previous studies. The results of this study show that when the construction cost that was predicted using the construction cost estimation model in the design stage was compared with the cost from the conventional standards, the suggested model in this study produced results with a very high confidence level.

• Korean Journal of Construction Engineering and Management
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• v.2 no.2 s.6
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• pp.81-89
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• 2001

Construction industry has particular properties of non-continuity of production, and non-stability of market comparing to other industries. Because of them, the practical construction cost is more difficultly recognized than in manufacturing industry, so, that is various according to many projects. Therefore, it is very hard work to standardize construction cost, and it is worthy of analyzing and measuring exactly construction cost. On this study, the trouble in producing expected construction cost with original cost calculation method is progressed by the data of cost items in complete works. On the basis of analyzing data, as expected cost of practical construction is measured, it can be referred to the method and the standard of indirect labor cost rate in construction.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.371-381
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• 2008

The systematic methodology for estimating construction cost approximately at planning and pre-design phase of a river facility construction project has not yet been established because of its unique characteristics including its relatively small project size in terms of cost. This research suggests a 4-level cost information structure and identifies critical factors affecting construction cost as a result of thorough analysis of accumulated historical cost data of river facility construction projects. Also, this research presents the framework of the approximate cost estimating methodology for river facility construction project a planning stage.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.5
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• pp.527-534
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• 2020

A significant factor in construction work is cost. At early- and advanced-stage design, costs should be calculated to derive realistic cost estimates according to unit price calculation. Based on these estimates, the economic feasibility of construction work is assessed, and whether to proceed is determined. Through the Korea Institute of Civil Engineering and Building Technology, the construction cost index has been calculated by indirect methods after both the producer price index and construction market labor have been reprocessed to easily adjust the price changes of construction costs in Korea, and the Institute has announced it since 2004. As of January 2000, however, the construction cost index was released, and this has a time constraint on the correction and use of past construction cost data to the present moment. Variables were calculated to compute a rough construction cost that utilized past construction costs through surveys of the producer price index and the construction market labor force consisting of the construction cost index. After significant independent variables among the many variables were selected through correlation analysis, the construction cost index from 1970 to 1999 was calculated and presented through multiple regression analysis. This study therefore has prominent significance in terms of proposing a method of calculating rough construction costs that utilize construction costs that pre-date the 2000s.

• Korean Journal of Construction Engineering and Management
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• v.13 no.1
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• pp.44-52
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• 2012

In the cost management of public construction projects, it is an important issue to develop an adequate cost data for estimating the predetermined amount by various methods. For a long time, a standard of estimation in korea is used as a basis for estimating the predetermined amount of public construction. However, they did not have a reasonable cost data based on a labor and equipment productivity analysis. For this reason, it is difficult to make a reasonable and efficient estimation of the costs, and this situation presents an urgent need for more accurate cost data to use in an early phase. This study analyzed the productivity of form work by the CYCLONE model, and presented the model on the number of optimal labor through sensitivity analysis. This CYCLONE model can be useful in analyzing productivity on the various sizes of form. Also, the regression model to estimate the daily output can be used in predicting the amount of labor. Considering the work duration in the regression model is expected to make the daily output estimation much more accurate.

• Korean Journal of Construction Engineering and Management
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• v.13 no.1
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• pp.67-76
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• 2012

There are index adjustment method and item adjustment method in estimation methods for price fluctuation rate of public constructions. A relevant regulation has put item adjustment method as a principle, but in most construction, contract sum adjustment has been made by index adjustment method. Hence, this study, by figuring out width and causes of the gap between index adjustment method and item adjustment method through direct comparative analysis, solved inequality caused by difference between them and suggested a rational way against irrationality of each method. For building operations of public housing construction, a detailed fluctuation rate by index adjustment method and item adjustment method of construction cost elements of the same construction, that is, direct material cost, direct labor cost and historical construction cost was estimated to analyze difference between two adjustments and establish its cause. Across the analysis, it was found that fluctuation rate by item adjustment method was estimated lower than that by index adjustment method and difference between methods for estimating fluctuation rate of quotation unit price and application of index unrelated to construction type and construction nature are main causes of the difference. This study has a significance in that, for smooth contract sum adjustment between contracting parties, it practically proved the real difference between adjustment methods by conducting comparative analysis of the difference in direct correspondence way.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.468-477
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• 2019

This study analyzed the major contents and results of revision through an analysis of the specifications and the field survey to revise the construction cost calculation criteria. The result of the survey found that the background processing difficulty was reduced due to an improvement of the quality level of the field floor, and the enhancement of the material's function brought a decrease in construction time and the application of various construction methods. In addition, the application of combined waterproofing methods using more than one material was increasing and the productivity differed according to the site and location. Based on these results, waterproof items were subdivided and applied to the composite construction method, and the input items were differentiated according to the material and construction method. The adequacy of the construction calculation criteria was ensured by presenting the criteria classified according to the construction area, and deleting the items that are not applicable and amending them to make them suitable for the specifications by reflecting the actual conditions of the construction on the site.

• Proceedings of the Korea Society for Simulation Conference
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• 1998.03a
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• pp.61-64
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• 1998

도로의 건설을 위해서는 통상 타당성조사, 기본계획, 기본설계 및 시공의 여러 가지 단계를 밟는다. 이들 각 단계를 거치면서 일반적으로 투자비 추정액은 실제 공사비와 더욱 근접하게 되게 되나, 타당성조사 등 계획단계에서의 추정액은 실제 공사비와 상당한 차이를 보이는 것이 일반적이다. 이러한 차이는 계획물량의 추정이나, 단가의 추정 등에서도 발생할 수도 있고, 구체적인 지질조사 등이 없는 상태에서 가정한 지질조건이나 공사조건 등에 대한 불확실성으로 인해 발생한다. 현재의 일반적인 관행은 이러한 투자비 추정단계에 작용하는 불확실성을 명시적으로 고려하여 투자비 추정치의 확률적인 분포를 산정하지 않고, 하나의 확정적인 추정치만 제시하고 있어 제시된 추정치의 신뢰도를 확인하기가 곤란하다. 본 연구에서는 현재의 관행과는 달리 투자비추정에서 관여하는 불확실성을 확률분포를 사용하여 명시적으로 고려하여 추정된 투자비에 대한 확률분포를 명시적으로 파악하려는 노력을 하였다. 추정된 투자비에 대한 확률분포는 Mont Carlo 시뮬레이션 방법을 이용하여 분석하였으며, 연구의 결과와 현재 각 계획단계에서 일반적으로 용인되는 추정오차와의 관계도 분석하였다. 결과에 근거하여 도로사업에 대한 투자비 추정을 효율적으로 할 수 있는 방법을 제시하였으며, 추가적인 연구방향도 제시하였다.