Site Overheads and Project Preliminaries are critical enabling cost components in residential real estate construction projects, yet they are commonly budgeted during approval or design development stages as broad percentages of the Cost of Construction. This approach provides speed at the feasibility stage but does not adequately reflect actual cost behavior after site handover. These costs begin from the first day of site activation and continue throughout the project lifecycle, making them sensitive to duration, manpower deployment, built-up area, tower count, temporary infrastructure, utilities, statutory compliance, safety requirements, sales-gallery operations, market escalation and vendor rates.

This paper presents MAPAN, a Model for Adaptive Project Site Overheads and Preliminaries Appraisal and Norms, developed as a driver-based budgeting framework for residential real estate projects. The framework classifies cost heads, maps each head to measurable dependencies, applies scaling logic, normalizes historical rates through escalation factors and validates assumptions using awarded work orders, vendor quotations and internal project references. A preliminary gap validation using selected project data indicated an average observed budget gap of approximately 53.93%, confirming the limitation of percentage-based provisioning. The main contribution of the study is not the variance itself, but the development of a structured, auditable and scalable budgeting method that improves cost accuracy, monthly cash-flow visibility, approval discipline and IRR predictability. MAPAN can serve as a practical governance tool for costing, budgeting, project operations, procurement and senior management decision-making.

Keywords - Site Overheads; Project Preliminaries; Driver-Based Budgeting; Construction Cost Management; Real Estate Projects; Cost Governance