Ask a sponsor what makes a project finance deal work, and you'll get an IRR. Ask a lender the same question, and you'll get a debt service coverage ratio. Both numbers come out of the same model, run off the same cash flow forecast, and they're answering fundamentally different questions. Confusing the two, or worse, presenting one to an audience that actually cares about the other, is how otherwise well-underwritten deals end up in covenant trouble.
I built a ten-year integrated model for an off-grid eco-luxury resort development in East Africa, a phased build on a remote lake island, financed in dollars against revenue that would eventually be earned in Kenyan shillings. The headline numbers looked good: a base-case unlevered IRR near 18 percent, a levered equity IRR near 21 percent, MOIC around 6x. If I'd stopped there, the investment committee would have approved it, and the deal would have been underwritten wrong.
The number that actually mattered sat somewhere else in the model. During the ramp-up period, before occupancy stabilized, projected debt service coverage dropped below 1.0x, which is worth pausing on. A DSCR under 1.0x means the property's operating cash flow, in that window, doesn't cover its debt payments, and it's the single clearest signal a lender's credit committee will look for, exactly the kind of finding a return-focused sponsor deck tends to bury beneath the exit multiple slide.
The distinction that actually matters
Here's the distinction CFA-level credit analysis insists on and equity-return thinking tends to skip past: IRR measures whether the deal creates value over its life. DSCR measures whether the deal can survive its own repayment schedule in the periods that matter most, which are almost never the stabilized years. A project can clear a 20 percent IRR on a ten-year view and still default on a debt payment in year two if nobody structured for the ramp-up gap. Lenders don't get paid in year ten dollars. They get paid on the schedule in the loan agreement, and if the coverage isn't there in month eighteen, the equity story doesn't matter yet.
The model also caught something the sponsor hadn't priced in. The bottom-up construction budget, built from freight and installation multipliers rather than a headline contractor estimate, came in above what the sponsor had told lenders to expect, a finding you'll never see in an IRR figure. It only shows up in a sources-and-uses table, and it's exactly the kind of gap that turns a financeable deal into a renegotiation six months after financial close.
What I take from this, and what I'd push any team structuring blended finance or private debt into Emerging Markets to sit with, is that a financing memo built primarily around IRR is optimized for the wrong reader. An interest reserve sized to cover the ramp-up shortfall, and a construction contingency stress-tested against the sponsor's own budget rather than accepted at face value, cost far less than the alternative: a covenant breach eighteen months into a fifteen-year facility, in a jurisdiction where restructuring a project finance loan is neither fast nor cheap.
The IRR tells you whether the deal is worth doing. The DSCR tells you whether the deal, as structured, will actually survive long enough to prove that IRR right.