Construction contingency in a development budget

Construction contingency is money set aside in the development budget for costs you are confident will occur somewhere but cannot yet attach to a line item. It is not padding, and it is not a slush fund. It is an honest admission that a budget written before the drawings are finished will be wrong in ways nobody can name yet.

How much contingency is normal?

Rabbet's guide to construction contingency states that "the industry standard for construction risk contingency is 3-10% of total hard costs." Note what that percentage is measured against. It is hard costs, not the total project budget, and the two produce meaningfully different dollar amounts on a project with heavy land or financing costs. If someone quotes you a contingency percentage, the first question is always what the base was.

The range is wide for a reason. A straightforward new build on a clean site sits near the bottom of it. A renovation, a site with unknown subsurface conditions, or a design that is only partly drawn sits near the top or above it. The percentage should also come down over the life of the project. As design resolves and contracts get signed, the remaining uncertainty shrinks, and a contingency held at its day-one percentage through construction is telling you the number was never being managed.

Owner contingency and contractor contingency are not the same pool

The general contractor may carry its own contingency inside the contract sum for its own risks. The owner carries a separate contingency outside that number for scope decisions, design gaps, and the changes the owner chooses to make. Confusing them produces the same overrun twice, once in the contract and once in your budget.

The distinction also decides who can spend it. Contractor contingency moves within the contract sum without touching you. Owner contingency should move only through a recorded decision, which in practice means it moves alongside the change order process.

The part that actually decides whether contingency works

Logging the drawdown. Every time contingency covers something, three facts need recording: how much, for what, and who approved it. Do that and the remaining balance is a real number you can act on. Skip it and the reserve becomes invisible, and the project reports as on budget until the day the buffer is gone and the next change order has nowhere to land.

This is the single most common way a development budget goes wrong quietly. The budget variance discipline that catches everything else depends on contingency being one of the tracked lines rather than a footnote. Contingency is also one of the five buckets a lender will want to see separately, so keeping it visible is not extra work invented for internal comfort.