• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.217-218
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• 2015

There are various standards and manuals on the quantity takeoff for construction estimation. However, a lot of time and money has been spent on retraining because of difference between practice and education. Therefore, the main purpose of this paper is to suggest improvement to analyze problems and limitations of the existing educational content for quantity takeoff. In order to achieve research objective, comparative analysis for quantity takeoff contents is carried out. This study will be extended to assist in effective quantity takeoff in building projects by supplementing the existing issues with quantity takeoff contents and developing a BIM-based quantity takeoff multimedia contents that use diverse media to increase the understanding on the subject for a non-professional.

• 한국BIM학회 논문집
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• 제7권2호
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• pp.16-24
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• 2017

It is very important to estimate accurate construction total cost needed early in the project. In the initial phase of the design, the project cost estimates are determined by total quantity from design documents and the variables that affect the calculation of the total cost of the project. In order to determine accurate total construction cost, the contractor has to produce detailed quantity information based on the drawings and specifications. The process of preparing quantification and cost estimation documents is still being worked out manually, and a lot of errors have been occurred in many cases. Recent advances in information technology have led to the BIM based quantity takeoff and cost estimation. However, there are some limits to the extent to which the current specifications for BoQ documents are computed from BIM model. This research analyze the current BoQ cases and analyze how to make quantity takeoff possible through BIM. The study defined five levels of quantity category that could be produced by BIM. Only about 40% or indirectly usable items can be used when information is extracted to BIM modelling. This is very insufficient to fill out the BoQ. The BoQ document structure quantity takeoff specifications should be simplified in order to BIM based cost estimation more efficiently.

• 한국CDE학회논문집
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• 제20권4호
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• pp.431-442
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• 2015

Currently, a BIM-based quantity takeoff (QTO) system is mainly focused on architectural projects. To perform this, diverse quantity takeoff methods such as an object-based automatic quantity takeoff, manual quantity and base functions of calculation have widely been utilizing. However, since BIM library for road projects includes structural elements associated with alignment, it is necessary to establish cost estimation system interlocked with historical cost using 3D library by each unit length. Accordingly, the aim of this study is to develop cost estimation model with using a historical cost approach so that it can be utilized in construction planning based on the BIM library for road projects. For this, based on the BIM library for road, the standardized quantity is estimated, and a process for calculating historical cost and a verification model with a 5D simulation was developed by mapping a WBS code with each BIM library object. This can be applied during the approximate cost estimation process in a project planning and an initial design phase for road projects. Besides, it is expected that these results will be utilized in constructing an optimal historical cost estimation process for project libraries.

• 한국BIM학회 논문집
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• 제1권1호
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• pp.13-17
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• 2011

최근 설계사무소의 단가 및 설계 생산성이 계속 낮아지면서 3차원 설계에 대한 관심이 사회적으로 높아졌다. 설계사무소의 영역을 넘어 건설사회의 설계팀에서 기획설계 및 건설현장의 시공검토용으로 BIM이 활용되기 시작하면서 많은 성공사례가 나오기 시작하였다. 그래서 근래 각광 받고 있는 BIM의 견적 활용성에 대하여 알아보고자 기본적인 콘크리트 량과 거푸집 량을 일반 2D 기반의 방식으로 물량을 산출하고, 3차원 캐드를 통해서도 같은 내용의 물량을 산출하여 BIM 견적의 활용성과 그 정확도를 검토하고 문제점들을 분석하여서 BIM의 효율성을 높이는 방법을 연구한다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.92-93
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• 2019

Estimates based on BIM makes it possible to perform from quantity take-off to construction cost estimates by using model, which is made in the phase of design and construction. As the BIM models are made up of the units of element, there an advantage of the automative quantity take-off, if the correction or change of element occurs. Work items, not included in the elements of the BIM model, are excepted from bill of quantity. Level of detail(LoD) of the BIM model can be improved for detailed estimates, but an excessive modeling for estimates is inefficient. This study presents the measure for selection and quantity take-off of work items, those are not expressed in the BIM model. The proposed method avoids the creation of excessive BIM Models and enables quantity take-off in conjunction with the element.

• 한국건축시공학회지
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• 제19권6호
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• pp.521-527
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• 2019

국내 철근콘크리트공사 현장에서는 철근량을 산출하기 위해 2D도면을 이용하여 복잡한 식을 사용한다. 내역서상의 철근 내역이 전체 철근량으로 작성되는 것을 고려했을 때, 현행 철근량 산출방식은 다소 비효율적이라고 판단된다. 이에 본 연구는 공공청사, 학교, 공동주택 각 유형별 10개의 프로젝트에 실적데이터를 바탕으로, 콘크리트량 대비 철근량 비율을 산출하여 사례를 검증하였다. 연구결과 AACE가 제시한 상세견적 단계의 정확도 범위 안에 포함되었으며, 프로젝트 전체 철근량은 상세견적 단계 오차율범위에도 포함 되는걸 확인할 수 있었다. 향후 부재별 유형에 따라 적용할 수 있는 보정 값을 산출하여 오차범위를 줄여 부재별 철근 산출량 오차율이 상세견적단계에서도 적용이 가능한 연구가 필요하다고 판단된다.

• 한국CDE학회논문집
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• 제20권2호
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• pp.124-132
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• 2015

When Building Information Modeling (BIM) was introduced at the early stage, it was only utilized as a three-dimensional visualization tool. Nowadays, however, BIM is being studied for increasing design productivity and managing enormous information on building life cycle. One of the representative research is developing 'common prototype BIM libraries'. BIM data made of common prototype libraries should be utilized in various ways, quantity takeoff, code checking, energy analysis and so on. However, common prototype BIM libraries are not enough to estimate accurate cost. For example, composite wall libraries should be divided into several single objects, wall structure and finishes, for the quantity takeoff and construction cost calculation. In this paper, we are suggesting an automated division algorithm of composite wall and developing a system prototype for it. This study is expected to reduce extra modeling work and contribute to fast and accurate cost calculation in the construction.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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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.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.358-363
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• 2007

철근콘크리트 구조물 형태의 건설공사에 있어 철근공사는 구조적인 측면이나 공사비 비중으로 볼 때 매우 중요한 부분을 차지한다. 철근물량의 정확한 산출은 이러한 철근공사의 효과적인 관리를 위한 기본적인 업무로 볼 수 있으나, 기술의 발전이나 개선 노력에도 불구하고 여전히 철근 숙련공의 경험이나 인력에 의존하는 전 근대적인 방식에서 벗어나지 못하는 실정이다. 따라서 본 연구는 철근 물량을 부재별/배근별로 보다 신속하고 정확하게 산출하기 위한 전산프로그램의 개발을 목적으로 하며, 이를 위해 연결된 부재의 철근 배근 상태를 감안하여 이음길이와 정착 길이, 피복두께등을 고려한 물량산출 알고리즘을 개발하였다. 개발된 프로그램은 전문 인력의 판단이 아닌 논리적인 게산에 의해 신속하게 수량을 산출할 수 있으며, 설계 변경이 잦은 철근공사에 유연하게 대처할 수 있다는 장점을 지니며 물량산출 과정에서 나온 결과 값을 바탕으로 시공 상세도를 자동으로 작성하는 기능을 포함한다.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.61-68
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• 2007

There has been a lot of research on and release of commercial systems that enable evaluation and visualization of construction methods. These have enabled the selection of good construction plans. However, the process in which engineers build 3D geometry, formulate a schedule and eventually synchronize them is still a time-consuming process. Changing any aspect of the geometry or the schedule and re-linking them is also time-consuming. Therefore, the engineers may compromise on getting the best solution. This paper describes a technique to automate the generation of multiple sets of schedules, quantity takeoffs and 4D visualization from a single 3D model.