A capital project arrives at the board with a number attached. Design, construction, contingency, timeline. What it rarely arrives with is the other number, which is what the project costs while it's happening.
That cost is real, it's often large, and it's usually absorbed rather than counted.
Every section out of service is revenue that doesn't return. In a building that sells out, it can't be recovered elsewhere. Multiply the seat count by the number of home dates by the average ticket price and the figure is usually bigger than people expect.
Suites, clubs, and hospitality areas are frequently the first spaces construction takes. They're also the highest revenue per square foot in the building, and the hardest to replace temporarily. A season without them is a season without the inventory that funds the rest.
Harder to model, and the one that lasts. A donor who spent a season in a worse seat than they paid for makes a decision at renewal. So does a season ticket holder who found the concourse closed and the walk longer. Neither of them files a complaint. They just don't renew.
A building mid-renovation can't host what it normally hosts. Concerts, neutral-site games, graduations, community events. Each one is revenue, and each one goes somewhere else.
Before approval, four questions produce most of the answer. How many seats come out, in which phases, across how many home dates? What premium inventory is unavailable, and for how long? What non-game events can't happen in the building during construction? And what does a season of reduced experience do to renewal rates, based on what happened last time?
None of this argues against renovating. It argues for knowing the real figure before the vote, because the project's return looks different when the cost of getting there is included.
Mostly, sequence. A project phased with the revenue calendar in view looks different from one phased purely around construction logic. Work moves into off-seasons. Phases overlap or separate. Temporary capacity gets used where it protects the most revenue, and skipped where it doesn't.
The construction budget is the number everyone debates. The other one decides what the project actually costs.