Planning note: Building rules, product standards, taxes and professional requirements differ by location. Use this guide for preparation, then verify local requirements.
Contingency covers uncertainty
A contingency is money reserved for unforeseen work inside the agreed project, not for routine items forgotten from the budget. First make the base estimate as complete as possible; then assess what cannot be known before work starts.
Hidden pipes, damaged substrates, access problems and product changes are common sources of uncertainty.
Risk is not equal on every project
Cosmetic work in a recently inspected room is normally more predictable than opening walls in an older building. Structural alterations, wet rooms, drainage and heritage materials create more ways for the scope to change.
List each uncertainty and consider its potential cost and likelihood. This produces a more thoughtful reserve than choosing a percentage without context.
Keep the reserve separate
Do not include contingency in the visible finish-shopping budget. Hold it separately and release it only after the core risks have passed.
Record every use of contingency so you know how much protection remains for later stages.
Know when to pause
If a discovery could affect safety, structure or a large part of the budget, stop and obtain suitable advice before proceeding. Spending quickly is not the same as resolving the risk.
When contingency is almost exhausted, reduce optional scope rather than assuming no further issues will appear.
Project checklist
- ✓ Complete the base estimate
- ✓ List hidden risks
- ✓ Match reserve to uncertainty
- ✓ Keep it separate
- ✓ Track every use
- ✓ Reduce scope if protection falls
Turn the plan into an estimate
Use the related free calculator to test quantities, labour and a broad regional cost range.
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