• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.232-233
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• 2021

As construction projects become larger and more complex in the construction environment, and as the Building Information Model(BIM) is technically introduced, the demand for construction costs in units of space is increasing. Cost estimating of spacial element can reduce the error in cost prediction method based on cost of work type and to utilize the construction cost data for each space in the design phase. The purpose of this study is to extract spatial statements by utilizing spacial information of quantitative statements based on items that are common elements of the Quantity Take-Off and Bill of Quantity.

• Korean Journal of Construction Engineering and Management
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• v.20 no.6
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• pp.89-97
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• 2019

Recently, BIM has been actively introduced in construction projects. In particular, the introduction of BIM in cost estimating process is expected to improve the accuracy and efficiency of the cost estimate. However, the quantity calculation and BoQ documents preparation process still require manual work. Although the BIM model may support quantification process, it is still problematic that the level of detail of the model must be very detailed to meet the items in BoQ. To address this, it is necessary to analyse the LOD criteria and to analyze the extent to which quantity can be computed according to the level of detail in the BIM model. For the analysis of LOD-based work items, the work item grades were divided into A,B, and C. In this study, the ratio and cost of each item that can be calculated at the LOD level in the detailed design phase are reviewed for each type of work, and the method for improving the quantity calculation using BIM is proposed. In the LOD 300 stage(Detailed design stage), the largest number of items in the class B, the major improvement class, are window and glass work. In addition, the most expensive type of work was analyzed by reinforced concrete work. In the future, it is necessary to suggest appropriate improvement way for items with high item ratios and items with high cost ratios. The results of this study are expected to be used as a BIM-based cost estimation or as basic data for improving the current BoQ system.

• Korean Journal of Construction Engineering and Management
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• v.11 no.2
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• pp.35-44
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• 2010

Currently, the unit price of public construction projects are not being evaluated appropriately for several reasons. First, the evaluation of the unit price differ per nature of the bidding process and its estimation process. In fact, pricing is determined to meet the total price in turnkey projects and to pass the low bid price deliberation process in unit price projects, and thus, such prices cannot be said to be reasonable prices per public project. After the contract is awarded, however, the prices determined without taking into consideration the characteristic of each bidding process and price estimate process are used for the valuation of progress payment, design changes, and escalation. Furthermore, this is also being applied to other low bid deliberation process as actual public project unit price, thereby affecting other processes as well. In effect, this system increases the risks for both the owner and the bidder who have determined the unit price. This research examines the risk factor and its extent in order to properly manage it in preparation for the future.

• 월간 기계설비
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• s.233
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• pp.47-54
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• 2009

공정거래위원회(위원장 정호열)는 지난 11월 6일 표준하도급계약서를 개정하고 이날부터 시행에 들어갔다. 개정된 표준하도급계약서는 발주자의 요청에 따라 설계변경이 이루어진 경우 증가된 물량 또는 신규비목의 단가는 설계변경 당시를 기준으로 산정한 단가와 이 단가에 낙찰률을 곱한 금액을 합한 금액의 100분의 50 이내에서 당사자간 협의해 정하도록 했다. 다만, 발주자의 요청 이외의 사유로 설계변경이 이뤄진 경우에는 종전과 같이 $\Delta$증감된 공사의 단가는 수급사업자가 작성한 산출내역서 상 단가를 적용하고 $\Delta$신규비목의 단가는 설계변경 당시 기준으로 작성한 단가에 낙찰률을 곱한 금액을 적용토록 했다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.23 no.3
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• pp.186-190
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• 1994

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6488-6494
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• 2013

Recently, BIM has attracted attention as a technology to improve the construction productivity. The BIM standards to be applied to the BIM project are necessary for using or connecting the current 2D-based drawing standards. To develop the standard for BIM-based QTO and cost, this paper focused on using QDBEx, which was applied to road project cost management and connecting QDBEx with IFC, which is the BIM data delivery format. The IFC schema was evaluated to determine if it is possible to use the converts to the QDBEx XML file. As a result, 66% of the whole was available to connect directly, and 17% was available to connect through the processing of instance. The remaining 17% was evaluated to determine if it was available to connect. In the future, improvements in the schema will be suggested based on these results.

• Journal of Korean Society of Steel Construction
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• v.21 no.1
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• pp.1-14
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• 2009

Estimating appropriate construction cost at the design phase is judged with one important issue to the efficient security and the execution of budget. Therefore, in this paper, to build fundamental data of appropriate construction cost for steel box bridges, the existing calculated document such as the quantity, unit price document and detail items etc.. was analyzed and the basic specification of the bridges was investigated. Also, by estimating the relationship between predetermined cost and construction items on the bridges, the paper is intended to produce basic data for the calculation of appropriate construction cost in planning phase. From the result, it was calculated ratio of construction item in the total construction cost and unit cost. And then it was deduced effect factor of construction cost in steel box bridge.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.198-199
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• 2014

In construction management the estimation procedure of construction expanses follows a series of submission phases: production of drawings, the assessment report, and the expanse report. In South Korea, it is a widely known issue that the expanse report only includes the net expanses at each construction phase and part, which makes it difficult to trace detailed basis from the records. This issue with inefficient record management should pose a number of problems, which result from discontinuation of construction record, unproductiveness for reproduction of records at each construction and submission phases for construction management, and failure to perform fair management among the contracting parties. Thus, the amendment in which the assessment report and the quantity estimation report reflect common codes to share throughout types of construction, space, and parts should be applied into practices so as to model production of acceptable reports and record.

• Korean Journal of Construction Engineering and Management
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• v.13 no.3
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• pp.99-108
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• 2012

The rough design information is only available from BIM(Building Information Model) based schematic design. So, it is difficult to obtain sufficient information for generating BOQ. Like 2D design, there are some problems that the results are depend on what the choice of cost estimator. However, the most research of BIM based cost estimation are focus on quantity takeoff, the consideration of work item for generating BOQ is insufficient. Therefore, this paper present automatic inference process of work items in a BOQ using ontology. The proposed process and ontology is validated through applying tiling construction. If the proposed process is utilized, it is expected the basis of developing generation method for consistent BOQ by resolving intervention of cost estimator's arbitrary decision.

• Journal of the Korea Institute of Building Construction
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• v.19 no.6
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• pp.521-527
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• 2019

Quantity takeoff and cost estimates in Korea are carried out in practice without any clear standards or standards. Especially, quantity takeoff of Reinforcing bar and BoQ documentation process is very complex using 2D drawings. In this study, 10 case sites were analyzed for the status of inefficient quantity takeoff and how the statement was prepared. In order to solve this problem, this study presented a method for calculating the quantity of rebars through the ratio of concrete volume for schools, offices, and apartment buildings, and analyzed the accuracy of results. In the future, it is expected that the error range can be reduced by defining the factors affecting the results and calculating the correction value for them.