Quantity based active schematic estimating (Q-BASE) model

The schematic estimating methods proposed in the literature have been limited in that they estimate construction cost in terms of composite cost but fail to consider other influential factors. In particular, when market prices of principle construction materials fluctuate, traditional cost estimation is less likely to accurately reflect these market changes. As an effort to address this issue, this research proposes a schematic estimating model that will decrease cost estimation errors during the preliminary design phase, while providing a tool for detailed estimation in subsequent design phases. The development of this model focuses on schematic estimating of building construction projects from the contractor’s perspective. For model validation and system prototyping, this research model is applied to cost estimating for building skeleton work of a mixed-use residential building project. The schematic estimating model proposed here will increase the reliability of cost estimation during the early stages of construction projects by actively responding to market and design changes.