• Korean Journal of Construction Engineering and Management
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• v.7 no.5
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• pp.167-176
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• 2006

It was found that Korean Standard of Estimate which has been used as the only basis of cost estimate of public construction projects had some side effects such as jerry-build construction and over-estimation because it failed to reflect the current price and the state-of-the-art construction methods in a changing construction environment. Therefore, the government decided to gradually introduce historical construction cost into cost estimate of public construction projects from 2004. This paper presents analytic criteria and a process model for deducing more current and reasonable historical construction cost for contract items from not only previous contract prices but also all of the other bid prices that were not contracted. The procedure of estimating actual unit cost proposed in this paper focuses on the removal of abnormal values including strategically too low or high prices and the time correction. In addition, basic research is conducted for the correction of actual unit cost through the analysis of fluctuation of bid price depending on bidding types and rates of successful bid. It is anticipated that the effective use of the proposed process model for estimating actual unit cost would make the cost estimation more current and reasonable.

• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.73-84
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• 2006

Standard safety management cost system was established in 1988 as a decree Number of 88-13, first time. And then, it has been revised fourteen times, up to now. A lot of practical investigations have been made for the revision but many problems at sites are continued to be put out so that it should be revised. This study is to find out hazard level of each work kinds through questionnaire and interview and investigate analyze the status which standard safety management costs have been used. Also, this study is to show reasonable rates of standard safety management costs in construction industry and to set up countermeasures against those problem after reviewing its status in korea with in Japan and Europe. Budget and actually performed amount of safety management costs in this study are investigated. costs for temporary work which is clarified in Japan is collected in order to compare domestic cost rate with Japanese one related to the total project amount. This study is to investigate eleven project kinds of domestic system, first, and to investigate eleven items of apartment bldg, office, civil work such as bridge, tunnel, dam, plant etc, secondly. Additionally, three items of gymnasium, railway, particular steel tower are investigated in this study. Also this study is to investigate and analyze performed costs of presently processing worker finished work so that it shows a new reasonable rate against standard safety management costs in construction industry, in order to make basical data and material to be systemized.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.146-147
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• 2017

Recently, as the living standards of residents in apartment houses continued to improve, the dispute of post management have also increased. one of the Issue, Concrete Cracks comprised high percentage of dispute. Especially, between criteria the cost of repairing defect and the judgement of defect isn't clear, they are a lot of dispute in this regard. Even though lots of the criteria about Inter-layer crack is existed by judging defects, In a court, they are judging their own criteria about Inter-layer crack. The purpose of this study is to compare and analyze Defect Judement Standard both MOLIT and Court, and to provide the Improvement for Defect Judgement and Repair Method of Inter-layer concrete crack.

• Journal of the Korean Society of Safety
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• v.21 no.5 s.77
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• pp.53-59
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• 2006

Standard safety management costs can not be applied to each site with same rate, it is very difficult, because it depends on the experience, work method, work kind, work progress schedule, and hazard level of each construction company. Therefore, this study is to find out hazard level of each work kinds through questionnaire and interview and investigate analyze the status which standard safety management costs have been used. Also, this study is to show reasonable rates of standard safety management costs in construction industry and to set up countermeasures against those problem after reviewing its status in korea with in Japan and Europe. The domestic system of standard safety management costs is not considered in the foreign country, while only related subjective items have been investigated and evaluated for this study. This study is to investigate eleven project kinds of domestic system, first, and to investigate eleven items of apartment bldg, office, civil work such as bridge, tunnel, dam, plant etc, secondly. Additionally, three items of gymnasium, railway, particular steel tower are investigated in this study. Also this study is to investigate and analyze performed costs of presently processing worker finished work so that it shows a new reasonable rate against standard safety management costs in construction industry, in order to make basial data and material to be systemized.

• Journal of the Korea Institute of Building Construction
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• v.10 no.1
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• pp.213-219
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• 2010

The research, based on 200 cases of small interior works in6 different floor area types of apartment in Busan, intended to compare the architectural work with the breakdown structure and analyze the cost of general small-scale interior work, by work type. The outcome of the research is outlined as follows. (1) Given the cost of small interior works for apartmentsranges from 10 million to 15 million won, which correspond to apartments ranging in size from $79.2m^2$ (24PY) to $105.6m^2$, it is necessary to implement a cost analysis for material cost and labor cost for these two types. (2) Given that small interior work for apartments comprises mostly finishing work, unlike the categoriesof general architectural work, it is more reasonable to classify the works into 9 categories,which include embellishment, wood, tile, paint, metal, toilet, sink & furniture, electric & mechanical and other works, instead of the 22 divisions stipulated in the Korean Architectural Standard Specification. (3) After reviewing the average cost of small interior work and rate by floor area, it was found thatthe average cost of 24PY was 10.5 million won, of which metal work accounts for 12.8%, embellishment work 17.8%, and toilet 19.7%, while sink & furniture appeared to be the highest with 22.1%, while for 32PY, average cost was 12.5 million won,which comprises 7.4% wood work, sink & furniture 20.2%, toilet 23.4% and embellishment work the highest at 28.6%, indicating that embellishment work accounts for the greater portion.

• Korean Journal of Construction Engineering and Management
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• v.9 no.2
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• pp.182-189
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• 2008

In private and public construction works, cost estimation and site productivity management are based on designed labor quantities calculated by the Standard Quantities per Unit (SQU). The designed labor quantities are regarded as the basis for insurance costs and safety and environmental costs and also affect the progress measurement of construction works. Even though the designed labor quantities from the SQU has been considered to be different from actual labor quantities put to construction works, there is no research that empirically analyzes the statistical differences. This study analyzes actual labor quantities of form workers, steel-bar fabricators, concrete pourers in reinforced concrete works of the 43 apartment projects, and compares the actual labor quantities to labor quantities from the SQU. It goes further to scrutinize the critical reasons underlying the differences through a survey on 65 practitioners and interviews with 32 site managers and supervisors. The regression models of labor quantities of the apartment concrete work produced by the present study will contribute to reasonable construction contracts based on the past actual costs and practical site management by the actual labor quantities.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.87-88
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• 2015

A defect dispute surrounding an apartment building is in constant trouble, a defect consulting is necessary that objective and impartial for solving a defect. The defect dispute about a defect lawsuit is conducted in the order that filling of lawsuit, consulting order, defect inspecting, estimating a repairing cost, writing a consulting report, submitting a consulting report, and decision by court. Of these, a step of defect inspecting is extensively investigated an occurred defect that each defect index and type from each part and place. At this time, it is collected of many data and created many information. For this, it need to organize and manage. The study is a modeling of field investigation work process that second phase of defect inspecting step. A literature study is defined a work until level 2. This study is defined the work until level 3 to 4. In addition, the modeling can do for using a job name, a place to job, a job to do, and a person concerned about defect consulting case. The modeling is expected a contribution of improving a defect consulting process and systematizing a judgment standard.

• Journal of the Korea Institute of Building Construction
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• v.11 no.6
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• pp.597-608
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• 2011

It has been often noted as a problem that as there are no objective and clear criteria for the repair cost estimate of persistent defects, when a claim arises in relation to an apartment construction, significantly different amounts of compensation may be given for similar defects based on the experience and tendencies of the construction experts asked to make a judgment. For this reason, this research aims to present defect managers with a more reasonable and objective estimation criteria and a system to determine the repair cost of defects based on an analysis of relevant factors. The research findings show that the historical cost system is applied first, and then a standard of estimation is used to estimate the cost for the items that are not included in the historical cost system. The criteria for the repair cost for each defect is as follows: the repair cost for defects arising from a regulation violation is determined by calculating the reconstruction cost of the parts in question after demolishing them; the repair cost for progressive defects is determined based on a contribution ratio proportional to the age of the building; the repair cost for repetitive defects is calculated by considering an alternative to maximize the intended function of the defective parts; and the repair cost for value depreciation defects is determined based on the ratio of the warranty period to the lapsed years. However, repair cost estimation for dual value depreciation defects should be studied in future research.

• Korean Journal of Construction Engineering and Management
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• v.23 no.1
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• pp.89-97
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• 2022

Recently, various problems such as reduced productivity, insufficient inflow of skilled manpower, reduced quality, and concerns about increasing safety accidents have appeared in the domestic construction industry. Stakeholder of construction project are considering the Off-Site Construction (OSC) method rather than the conventional on-site construction as an alternative. Despite the importance of decision making in the early stage of the adoption of OSC, there is a lack of methodologies for rational decision making. In this study, a decision making system has been developed to derive the final construction cost score by deriving the project characteristics, selecting the construction difficulty index, and developing a cost model for each construction method alternatives to calculate the standard construction cost. Using this system, the OSC method can be effectively evaluated in terms of its feasibility in the early stage of construction

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.1
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• pp.28-42
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• 2009

In the wake of categorizing the design changes occurred during the period from 2004 till the first half of 2006 in Choongcheong province area, based on purpose and reason of design changes identified by the Korea National Housing Corp, it included 11 types such as the image of the apartment complex, scenic elements, consideration by the user, prevention of the defect, constructability, site conditions, incompatibility between the activities, superordinate standard, prevention of civic complaints, design details and others, along with 47 subordinate elements. And the evaluation intended to identify the corelation between the number and time of design change approval, frequency and scale of design change by type and the cost variations indicated that; firstly, enhancing the image of the apartment complex proved to be the main reason for design changes, accounting for 22% in terms of frequency and 54.9% in terms of cost variation. Secondly, the higher the increase in cost by design change aimed at improving the image of the complex, the lower the decrease in cost by design change for uncertain reasons, dubbed the inverse proportional relations, indicating that the design changes for uncertain reasons were mostly aimed at reducing the construction cost. Thirdly, with regard to the number of design change approval and the time of the initial approval, twice or less and 90 days or less before completion of the construction work, respectively, accounted for $52{\sim}53%$, indicating the design change deliberation and approval tended to have been carried out collectively in the form of ex post facto approval, which seemed to be attributable to the attempt of reducing the construction cost or budget problem, as a result of comparing with the cases in which the cost was reduced.