Abstract
This study presents a methodological framework for the parametric assessment of residential construction costs, designed to support decision-making processes through systematic cost monitoring and continuous updating. The approach is grounded in a Work Breakdown Structure (WBS) decomposition, organising the building process into hierarchical intervention categories and working clusters that enable clear cost attribution and aggregation at each level. The framework is applied to fourteen residential case studies located predominantly in the Municipality of Rome, Italy, organised in two phases: Phase I (five cases, with one excluded as anomalous) and Phase II (nine additional cases). A logical–deductive procedure introduces homogenization coefficients for accessory surfaces relative to the primary usable area, enabling the derivation of consistent, comparable unit construction costs and analysis of the relative economic weight of each cost component. Results are validated against official parametric benchmarks and delivered through operational tools—including interactive project sheets and GIS-based maps—that support both analytical interpretation and territorial comparisons. The framework is designed to be readily updatable through the integration of new cost inputs. Overall, the proposed model constitutes an applied instrument for monitoring and analysing construction costs in relation to building typology and territorial context, providing concrete support for the planning and economic management of residential construction.