# Infrastructure_Debt_Investor_Models.xlsx: start here

## What the file is

The companion workbook of *The Infrastructure Debt Investor* (Julian R. Sterling). It rebuilds the three fictional loans the book follows, year by year: Wexmoor Schools (an availability-based senior loan), Tarnbeck Wind (a senior loan with twelve contracted years and a merchant tail) and Carrow Heat (a holdco loan behind a district heating business with its own senior debt). Every figure the book prints from the model is recomputed by live formula. Amounts are US dollars in millions. Year 1 is the first year of operations.

Blue numbers on a light blue background are inputs you may change. Black numbers are formulas.

## Which tab answers which chapter

| Tab | What it holds | Chapters |
|---|---|---|
| README | How to use the file | |
| Wexmoor | Sizing, schedule, ratios, live stress with the loan fixed, secondary price | 1, 4, 5, 8, 12, 13 |
| Wex_Stresses | Eight stress cases side by side, closed-form breakevens | 5 |
| Tarnbeck | P50, P90, P99, contracted and merchant sizing, live stress, breakeven price | 3, 4, 6, 8, 10, 12 |
| Carrow | Opco waterfall and lock-up, holdco cover, reserve, PIK, value, LTV, breakevens | 2, 4, 7, 8, 12 |
| Pricing | Yield including fees, WAL, expected loss, spread after EL, threshold PDs | 9 |
| Fund | Portfolio weights, net yield, concentration | 13 |
| Interview | The sixty-minute sizing case | 14 |
| Checks | The book's printed figures beside the live formulas; ends with ALL CHECKS OK | Appendix A |

## Sizing inputs and stress inputs

Each loan sheet has two kinds of input. A sizing input (target DSCR, tenor, gearing cap, the statistic the loan is sized on) re-sizes the loan: that is a sensitivity. A stress input (a cost shock, a lifecycle shock, a deduction, lower indexation, a merchant price shock, a bad wind year, a permanent output loss, an EBITDA shock, the PIK toggle) changes the cash flow and holds the signed loan fixed: that is a stress, and only a stress tells you how close the loan comes to failure.

## Recalculation

The file recalculates when you open it. It has no macros, no data tables and no circular references, so it works the same in Excel, LibreOffice and Google Sheets. The Checks sheet reads ALL CHECKS OK at the default inputs; after you change an input, some lines read DIFF, which is expected. To go back to the book's figures, download the file again.