Cost estimation methodology using database layer in construction projects

Recently, as the scale, structure, capacity and use of buildings are more complicated in construction projects, it is more difficult to estimation project's costs. Because its project's scale is much bigger than any other project's one and total project cost is concluded after project is finished, it is important to make cost estimation method and system. In past, it is possible to estimate cost only using simple method. But, to cope with the now and future situation, it is necessary to have to study not only method but also database. In this paper, using real structure data of Korea public residential buildings, we discuss cost estimation based on the quantity of material at design stage. To estimate costs accurately under complicated situations, After selecting influence factors, cost database, named Database Layer, is created. And then, cost model is suggested using Case-Based Reasoning and Regression. This paper is expected to improve the accuracy and contribute to estimation studies under various conditions.