Give a competent team a data room and they will usually land the capital cost within a defensible range. Equipment is quotable, designs are comparable, and a sponsor who has got as far as raising money has usually costed the build. The number that decides the return, and the one that is most often wrong, is not the capex. It is the schedule.
Why the timeline is where the money is
An infrastructure return is sensitive to when revenue starts, and delay compounds: financing cost accrues, contracts slip, and a first-mover thesis quietly becomes a me-too one. A project that comes in on budget but eighteen months late can miss its case entirely while every line item in the capex model was correct.
The schedule is also where the sponsor’s document is weakest, because the Gantt chart is a plan, not a forecast. It shows the sequence the sponsor intends. It rarely shows the process durations the sequence actually depends on.
Where schedules actually slip
- Permitting and approvals. National and county-level consents, environmental assessment, and sector licences each run on their own clock, and they are frequently sequential rather than parallel.
- Grid interconnection. A plant can be mechanically complete and still not energised. Interconnection — the studies, the works, the queue — is a classic critical-path item that sits outside the sponsor’s direct control.
- Land, wayleaves, and access. For anything linear — fibre, transmission — securing continuous right-of-way is often the real critical path, and a single hold-out parcel can stall a corridor.
- Lead times, logistics, and FX. Long-lead equipment, port and inland logistics, and currency or import friction stretch procurement in ways a domestic Gantt understates.
How we test a schedule
We rebuild it from the bottom up against real process durations, not the sponsor’s target dates, and we look for two things. First, whether the stated critical path is the true one — often the binding item is interconnection or a permit, not construction. Second, the single longest-lead item, because that is what actually sets the earliest credible start of revenue.
Then we frame the finding the way an investment committee can use it: not “the schedule is optimistic,” but what would have to be true for it to hold — which approval, which interconnection milestone, which delivery — and which of those are inside the sponsor’s control and which are not.
Price the schedule with the same rigour as the capex. It is the side of the model where the optimism lives, and the side where the return is won or lost.