Every month a construction project runs past its planned schedule, interest keeps accruing on the financing behind it. This calculator quantifies that specific cost — built primarily for real estate developers and project owners, though the same planned-vs-actual interest logic applies to any project owner carrying construction-period financing.
Construction financing — whether a bank construction loan, an NCD, or another debt instrument — accrues interest for as long as it remains outstanding. When a project runs past its planned construction duration, the financing typically stays outstanding for longer too, which means additional interest accrues that the original project appraisal never budgeted for. This is a real, often-underestimated cost of schedule delay — separate from and in addition to any direct cost overrun on the construction itself.
A developer financing ₹5 crore of average outstanding construction cost at 10% p.a., planned for a 12-month construction period, would budget roughly ₹50 lakh in financing cost. If the project actually takes 18 months, the same financing now costs roughly ₹75 lakh — an additional ₹25 lakh that a 6-month schedule slippage alone accounts for, independent of any change in the construction cost itself.
Track planned vs. actual construction duration explicitly as a financing-cost driver, not only as a project-management metric — and model the financing-cost impact of a schedule slippage as soon as it becomes apparent, rather than only discovering it in the final project cost reconciliation.
Experienced developers model financing cost as a function of schedule, not just of the sanctioned loan amount — and revisit that model the moment a delay becomes likely, rather than waiting for the final cost reconciliation to discover the impact.
Rebota's Project Dashboard tracks planned vs. actual project duration alongside cost data, so a schedule slippage and its financing-cost implication are visible together rather than in separate reports.
