How do I know a capital project will finish inside the money raised for it?

You cannot know in advance, but you can see early whether it is on track. The signal is committed cost, not spent cost. Overruns show up in purchase orders, change orders and contingency drawn down, well before they show up in invoices.

Most project reports compare what has been spent with the budget. By the time spent cost runs over, the money is already committed. The useful comparison is what has been committed plus a current estimate to complete, line by line, against the budget. Done monthly, it tells you whether the money raised will reach the end.

The pattern is familiar. Contingency is drawn early on things that were foreseeable. Change orders are approved one at a time and never added up. The estimate to complete is not revised because nobody wants to be the one who revises it. The gap appears late in the project, when raising more money is hardest and most expensive.

Seeing it early is what lets you act while there are still choices: re-scope, re-sequence, or go back to your lenders or investors before the money runs short rather than after.

What you can look at this week: ask for committed cost to date and an estimate to complete for each budget line, and put them next to the budget. Check how much contingency is left and what it has been used for. Then read what your financing documents require if the cost to complete exceeds the funds available.