• Korean Journal of Construction Engineering and Management
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• v.25 no.2
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• pp.56-68
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• 2024

A construction standard production rates system for the factory built and on-site installation phases of OSC (Off-Site Construction)-based precast concrete (PC) structures in apartment buildings was recently proposed to establish an objective cost standard (Lee et al., 2021). In addition, the Korean government has taken steps to improve the institutional foundation for the systematic calculation of PC construction costs such as revising construction standard production rates for major components that can be applied to the on-site installation phase of PC method. In this study, we analyzed the results of a field survey of apartment building PC structures and collected expert opinions to develop factory-built and on-site installation standard production rates that can be applied to apartment building PC method. We also propose directions for improving the standard production rates so that they can be applied to the site and component of apartment buildings by comparing them with the current standard production rates. This study also derived the cost characteristics and cost reduction measures of PC construction by calculating the construction costs using the developed rates and comparing the construction costs with the RC methods of apartment buildings of the same scale. The construction standard production rates for PC construction derived in this study are expected to contribute to the spread of PC construction by ensuring the objectivity and consistency of the results of PC methods cost estimation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.226-227
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• 2019

The basic type construction cost which is the base of the building cost estimation is being adjusted according to the price changes by utilizing the apartment construction cost index in order to flexibly operate it. In this study, we analyzed the change trends and characteristics of the housing cost index for the basic type building cost model project operated from September, 2012 to March, 2018. As a result, the increase in material costs is slight while the share of the labor cost increased in the construction cost due to the rise of labor unit price, leading to a perceived increase in sensitivity of labor costs. We should be careful to keep the sensitivity of the material cost and the labor cost to an appropriate level so that the index may not be distorted.

• Korean Journal of Construction Engineering and Management
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• v.16 no.1
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• pp.110-118
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• 2015

The standard production unit system is the most basic element in our country construction. However, this standard production unit system shows a large difference in the actual amount of labor input for works at the Apartment housing construction, Therefore, it may be a reasonable alternative to estimate the cost of construction by historical cost data, works will be calculated the cost of labor must determine the exact amount and It is necessary to determine the exact amount of labor input for the construction progress management. This study examines the results of comparing the standard production unit system and the actual amount of labor counting in apartment housing construction was completed in the metropolitan area since 2000, the following results were obtained. the actual amount of labor input are looked for 1.184person/1000 of masonary, $0.084persons/m^2$ of plaster, $0.039persons/m^2$ of Waterproofing, $0.059persons/m^2$ of tile at the Apartment housing construction. in the actual amount of labor counting Compared with standard production unit system, masonry ratio of 59.8%, plaster ratio of 41.3%, waterproofing ratio of 31.5%, tile ratio of 34.3% and The labor rate in the works was the lowest in the plaster. was relatively high in the masonary. Therefore, the amount of labor country apartment housing construction is preferably calculated on historical cost data. But it seems that the amount of labor necessary complement ongoing close enough to the actual standard production unit system a major variable in construction management.

• Journal of the Korea Institute of Building Construction
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• v.6 no.1 s.19
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• pp.117-122
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• 2006

Apartments construction is a one of largest parts in buildings construction. In apartments construction, work interferences are frequently occurred in work processing because workspaces are very various and numerous. However, though work process is important for mainly influencing to the schedule, quality and cost of apartments construction, these work interferences are considered a kind of uncertainty, which is difficult to anticipate at construction planning stage, in work processing. Therefore, this study proposed the measures for work interference reduction in apartment buildings construction and the actual planning for practices. The results can be summarized as follows: (1) the standard of work process is checked regularly. (2) The scope of work and work process is adjusted. (3) The standard of drawings process and cost about work interferences work profess is established.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.33 no.12
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• pp.11-18
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• 2017

The safety inspection cost of the construction work was based on commercial facilities classified as a single building. Therefore, it is not possible to fully reflect the characteristics of the multi-building construction project such as apartment houses. Therefore, this study suggests a reasonable estimation model that can fully reflect the characteristics of the multi-building construction project. The safety inspection cost estimation model proposed two models such as construction cost ratio method and cost plus fixed fee method. And these models were simulated by the apartment construction work and compared with the current standard. As a result, the current construction cost ratio method has shown that the safety inspection cost tends to be overestimated as the construction size increases. Therefore, the proposed model has reflected characteristics of the multi-building construction project, so that it can reasonably estimate the safety inspection cost more than the current standard.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.48-49
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• 2019

The number of disputes over defects after completion of construction work in apartment buildings is increasing every year. In this situation, the prediction of reasonable defect repair costs is very important. In this paper, we are going to collect basic data for predicting defect repair costs through the correlation analysis of the construction period and defect repair cost of apartment houses. For this purpose, first of all, the construction period and defect repair cost of apartment houses were analyzed to analyze the construction period for each type of work, the construction period for each project type, and the construction period for each standard calculation. Next, the correlation between defect repair cost and the independent variables of the candidate was conducted. According to the analysis, the ratio of framing air, the ratio of finishing air, and the number of delay days showed strong correlation.

• Journal of the Korean housing association
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• v.23 no.6
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• pp.49-59
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• 2012

This study suggested a new model in consideration of long life and constructability of apartment house suggested in the former part. New model suggested the possibility of cost saving based on the idea that people trend to reject because of the recognition that the new model would cost a lot of expense which work as the barrier for the expansion and distribution at the local market so as to prepare the ground for its activation. The Study was aimed at verifying the possibility of cost saving through comparing it with the existing standard apartment house system centered on the skeleton and cladding system among the new structural design models suggested in the former part. Assuming that these existing standard both models should be changed structural design into new model system, the quantity volume, cost and construction period along with the alteration of finished materials between two models were compared altogether. Simultaneously BIM library was built for easy taking-off bill of quantity and consideration of working methodology for construction working cycle, which was translated into construction cost so as to derive the cost of the two subject systems to be counted. Through the analysis, it was concluded that new model would secure variability in the future and constructability along with shortening the construction period (29%) and achieve cost saving (13%) of construction against the those of existing model.

• Journal of the Korea Institute of Building Construction
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• v.4 no.4
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• pp.117-126
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• 2004

Construction industry is faced with the problems such as the quickly changeable circumstance and increasing construction companies due to regulation mollification of company registration. In order to overcome these problems, new estimation system based on historical estimation cost is ready to introduce by government step by step. But the time of transition for estimation system causes another problems such as chaos addition to simultaneity of a standard of estimation system and new estimation system, lack of related regulation, accumulation of historical extensive cost data, and adjustment methodology when historical estimation data is applied to next projects. The purpose of this study is to suggest the change factors by activities for estimating historical cost for apartment housing projects. New estimation system is based on historical construction data. For application of this system, the standard adjustment methodology system is necessary. and extensive cost data should be accumulated under an unified construction work classification system. Therefore in this study, according to the construction work classification system, every apartment housing project was classified to 16 work classifications, and 7 major composed items which occupy more than 85% of construction costs are analyzed by detailed activities and by average ratio and maximum ratio each of them. In the result of the study, furniture work, foundation work and masonry work are the works which have big gap of costs between average ration and maximum ratio. In addition to suggestion of change factor by work species, 5 qualified construction specialists are interviewed and change factors in 7 major works are analyzed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.158-159
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• 2014

There is urgent for defect consulting work to standardize the investigated method, repaired and reinforced method, and estimated cost about defect in increasing a defect lawsuit of apartment building. For the purpose of developing the standard process of defect consulting work, the review that a used process in law and institution should take precedence. There is not prepared the national standard for defect consulting but is dependent on an experience and a practice of consultants. This study analyzes defect consulting case, defines main steps for developing the standard process, and draws phased work factors. As systemizing this, it is expected to apply to basic structure for developing the standard process of defect consulting work for the next.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.177-178
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• 2011

Recently a great deal of people are taking legal action against the housing provider due to the defects of their Apartment house. And most of the housing companies are spending a huge amount of expenses and efforts to keep their brand value. This essay will carry out time series analysis the 20 housing district which are constructed by huge construction companies. This analysis itemised by metropolitan area(Seoul) and others to keep the degree of reliability, and converted future defect maintenance cost into current cost applied by discount rate to figure out suitability of defect maintenance cost. Even though, this essay is not able to represent standard of defect maintenance cost due to the insufficiency of record, while it will be assisted as a referance when long-term record of time series is estabilished.