A Feature Ontology to Support Construction Cost Estimating

Current building product models explicitly represent components, attributes of components, and relationships between components. These designer-focused product models do not represent the features of building components that are important for calculating construction costs, such as penetrations and component similarity. To provide product models that are useful to cost estimators, we need to transform current product models into estimator-focused prodect models that represent the features of building components that affect construction costs. Previous research efforts identify many of the different features that affect construction costs but they do not provide a formal and general way for practitioners to represent the features they care about according to their preferences. This paper presents the vocabulary we formalized to represent the different types of features of building product models that are important to cost estimators of building construction. The vocabulary allows estimators to reporesent their varied preferences for naming features, specitying features that result from component intersections and the similarity of components, and grouping features that affect a specific construction domain. The feature ontology provides the structure for transforming designer-focused product models into feature-based product models that support cost estimating. We also describe the framework we developed that uses the ontology to represent features in a project-independent way so that they can be reused from project to project to create estimator-focused feature-based product models from a given product model. Tests provide evidence for the power and generality of the feature ontology. The main contributions of the paper are the feature ontology and the framework developed to capture this knowledge from estimators.