An Ontology for Relating Features with Activities to Calculate Costs

It is the cost estimator's task to determine how the building design influences construction costs. Estimators must recognize the design conditions that effect construction costs and adjust the project's activities, resources, and resource productivity rates accordingly to create a cost estimate for a particular design. Current tools and methodologies help estimators to establish relationships between product and cost information to calculate quantities automatically. However, they do not provide a common vocabulary to represent estimators' rationale for relating product and cost information. This paper presents the ontology we formalized to represent estimators' rationale for relating features of building product models to construction activities and associated construction resources to calculate construction costs. A software prototype that implements the ontology enables estimators to generate activities that know what feature requires their execution, what resources are being used and why, and how much the activities' execution costs. Validation studies of use of the prototype system provide evidence that the ontology enabled estimators to generate and maintain construction cost estimates more completely, consistently, and expeditiously than traditional tools.