Sources and Uses Modelling
Executive Summary
Key Takeaways
- ✓ The sources and uses statement should be built as a live, formula-driven reconciliation, not a static summary with a hardcoded balancing figure.
- ✓ Total uses (construction cost, interest during construction, fees, contingency, reserve funding) and total sources (debt sized against total uses, plus equity as the residual) are mutually dependent, creating a structural circularity that must be resolved the same way as other project finance circularities.
- ✓ Equity should be sized as the residual once maximum debt capacity is determined through debt sculpting, not fixed as an independent assumption that the model then forces sources and uses to balance around.
- ✓ A sources and uses statement that balances only because of a hardcoded plug figure signals an error elsewhere in the model, most commonly an incomplete uses list or a static IDC estimate.
- ✓ The sources and uses statement should be presented as a standalone summary schedule, since it is the schedule most frequently reviewed first by a lender or auditor.
Institutional Definition¶
Building a sources and uses statement is the process of constructing a live, formula-driven reconciliation between every source of funding for a project finance transaction and every use of that funding, resolving the structural circularity between total uses and debt sizing so the statement balances automatically as assumptions change, rather than through a static, hardcoded figure.
Why This Is a Construction Discipline, Not a Summary Exercise¶
A sources and uses statement is often treated as if it were simply a presentation summary, assembled after the rest of the model is built. In a correctly constructed project finance model, it is the opposite: the sources and uses reconciliation is a live output of the model's construction budget, financing structure, and debt sizing logic, and building it correctly requires resolving a genuine circular dependency, not just formatting a summary table.
Build Sequence¶
Step 1 — Assemble the Uses Side¶
Total uses is the sum of independently calculated cost components:
- Construction / EPC cost — from the construction budget.
- Interest during construction (IDC) — calculated from the drawdown schedule, described in full on Construction Period Modelling. This is the component that introduces circularity.
- Financing and advisory fees — from the fee schedule, typically a percentage of debt quantum plus fixed advisory costs.
- Contingency — from the construction risk assessment, see Construction Contingency.
- Initial reserve account funding — where reserves are funded upfront rather than accrued from operating cash flow, see Reserve Accounts in Project Finance Models.
Step 2 — Size Debt Against Total Uses¶
Debt is sized as the maximum quantum the project's projected operating cash flow can support at the lender's minimum DSCR and LLCR, through the debt sculpting calculation, subject also to any maximum gearing constraint. Because financing fees are frequently calculated as a percentage of debt quantum, and IDC depends on the debt drawn, this step feeds back into the uses side, reinforcing the circularity.
Step 3 — Size Equity as the Residual¶
Equity is calculated as total uses minus total debt sources (and any other non-equity sources such as grants), not fixed as an independent assumption. This ensures the sources and uses statement balances structurally, as a mathematical consequence of how it is built, rather than through a plug.
Step 4 — Resolve the Circularity¶
Because IDC depends on the drawn debt balance, which depends on total uses, which includes IDC, the sources and uses calculation is circular. This is resolved the same way as other project finance circularities: a controlled iterative calculation, explicitly enabled and documented in the model's assumptions log, or a closed-form algebraic solution where the drawdown profile permits one. See Circularity in Debt Models for the general treatment of this resolution.
Common Construction Errors¶
Error 1 — Hardcoded Balancing Plug¶
The most common error is a hardcoded adjustment entered on either the sources or uses side, forcing the two totals to match. This masks whatever real structural error caused the imbalance and means the statement will not correctly respond to any change in the underlying assumptions.
Correct approach. Every line on both sides should be formula-driven from its underlying calculation, with no manual override.
Error 2 — Incomplete Uses List¶
A cost category, most commonly financing fees or initial reserve funding, is omitted from the uses side entirely.
Correct approach. Cross-check the uses list against the full set of cost categories identified in the transaction's term sheet or financing documents before finalizing the schedule.
Error 3 — Static IDC Estimate¶
IDC is entered as a fixed lump-sum assumption rather than calculated from the actual drawdown profile and interest rate.
Correct approach. Calculate IDC through the drawdown mechanics as described in Construction Period Modelling, feeding the result back into total uses.
Error 4 — Equity Fixed Before Debt Sizing Converges¶
Equity is entered as a fixed amount decided early in structuring discussions, before the debt sculpting calculation has converged on its final debt quantum.
Correct approach. Treat equity as the calculated residual once debt sizing is finalized; where a fixed equity commitment is genuinely a transaction term (for example, a sponsor has committed a specific amount regardless of debt capacity), model debt as the residual instead, and represent the fixed side as the true independent assumption.
Audit Checks¶
Balance check. Confirm total sources equals total uses through formula alone, with no hardcoded adjustment on either side.
Completeness check. Cross-reference the uses list against the transaction's term sheet or financing documents to confirm no cost category is omitted.
IDC traceability check. Confirm the IDC figure in uses ties directly to the drawdown schedule's interest calculation, not a static assumption.
Circularity documentation check. Confirm the sources-and-uses circularity is explicitly documented in the model's assumptions log.
Best Practices¶
| Best Practice | Why It Matters |
|---|---|
| Build every line on both sides as a formula, never a hardcoded plug | Ensures the statement responds correctly to any change in the underlying assumptions |
| Size equity as the residual once debt capacity is determined | Reflects how project finance transactions are actually structured, and keeps the statement balanced structurally rather than by adjustment |
| Cross-check the uses list against the term sheet | Catches an omitted cost category before it becomes a funding shortfall discovered during construction |
| Present sources and uses as a standalone summary schedule | Supports the schedule's role as the first thing a lender or auditor typically reviews |
Further Reading¶
- IFC, Project Finance in Developing Countries, International Finance Corporation
- ICAEW, Financial Modelling Code, Institute of Chartered Accountants in England and Wales
Continue Reading¶
Prerequisites¶
- Project Finance Model Audit — the parent pillar
- Project Finance Model Structure — the overall module architecture this guide fits within
Related Technical Guides¶
Related Glossary¶
Related Products¶
- Financial Model Audit Engine (FMAE) — deterministic structural auditing referenced throughout this guide
How OXXON tests thisRun a free structural check with FMAE
Frequently Asked Questions
What is the correct sequence for building a sources and uses statement?
Build the uses side first from the underlying construction budget, financing fee schedule, contingency assumption, and reserve funding requirement, including interest during construction calculated through the drawdown mechanics. Size debt against this total uses figure through debt sculpting, then size equity as the residual to complete total sources.
Why does the sources and uses statement involve circularity?
Because total uses includes interest during construction, which depends on the debt drawn, which depends on total uses (since debt is sized against it). This mutual dependency is resolved the same way as other project finance circularities, through a controlled iterative calculation or a closed-form solution.
Should equity be a fixed assumption or a calculated residual?
Equity should be calculated as the residual once maximum debt capacity is determined through debt sculpting against the lender's minimum DSCR and other covenant thresholds, not fixed as an independent assumption the model is forced to balance around.
What does it mean if sources and uses only balances with a hardcoded plug?
It signals a structural error elsewhere in the model, most commonly an incomplete uses list (a fee or contingency line omitted) or an interest during construction figure estimated statically rather than calculated from the actual drawdown profile.
How should the sources and uses statement be presented in the model?
As a standalone summary schedule, visible without navigating into the underlying calculation detail, since it is typically the first schedule a lender or auditor reviews.
Related Articles
Sources and Uses (of Funds)
A sources and uses statement is the schedule in a project finance model that lists every source of funding for a transaction, senior debt, subordinated debt, sponsor equity, grants, and any other funding instrument, against every use of that funding, construction costs, capitalized interest during construction, reserve account funding, financing fees, and contingency. The two sides must reconcile to the same total with no unexplained balancing figure. It is typically the first schedule built in a project finance model and the one lenders review first, because it is the clearest single statement of how a transaction is actually funded and what that funding is spent on.
Interest During Construction (IDC)
Interest during construction (IDC), also called capitalized interest, is the interest that accrues on project finance debt drawn during the construction phase, before the project reaches commercial operations and begins generating revenue to service that debt. Because there is no operating cash flow available to pay this interest as it accrues, IDC is typically capitalized, added to the total funding requirement and financed as part of the debt facility, rather than paid in cash during construction. IDC is calculated on the cumulative drawn balance, which itself depends on the total funding requirement, creating a circular reference that is one of the most common structural features of a project finance construction-phase model.
Construction Period Modelling
The construction phase of a project finance model has no operating revenue and is governed entirely by funding mechanics, the construction cost curve, the drawdown profile, interest during construction, and contingency drawdown, culminating in a commercial operations date (COD) test that governs the transition to operations. This guide sets out how to build each of these mechanics and the common errors that misstate the total construction-phase funding requirement.
Drawdown and Funding Mechanics
The drawdown schedule translates the total funding requirement from the sources and uses statement into a period-by-period draw of debt and equity during construction, governed by a funding competition rule that determines the relative proportion of debt versus equity drawn each period. This guide sets out how to build pro-rata, equity-first, and debt-first funding competition mechanics, how to sequence multi-tranche debt drawdowns, and how standby facilities interact with the base drawdown schedule.
Gearing Ratio
The gearing ratio, also called the debt-to-equity ratio or leverage ratio depending on how it is expressed, is the proportion of a project finance transaction's total funding provided by debt rather than equity. It is read directly off the sources and uses statement as total debt sources divided by total sources (debt-to-total gearing) or total debt divided by total equity (debt-to-equity gearing), and is one of the central negotiated parameters of a project finance transaction, since it directly determines how much of the project's risk is borne by lenders versus sponsors.