A refurbishment budget without a contingency can look pleasantly precise. Every pound appears allocated and the projected outcome may look stronger. The problem is that an existing building does not always reveal everything before work begins. Precision on a spreadsheet is not the same as certainty on site.
A contingency is an allowance for additional costs that may arise as the project develops. It should be discussed as part of the funding plan, with clear rules for using it. It is not an excuse for a vague specification, and it should not be counted as profit before the work is complete.
Start with a properly defined scope
The first defence against an unreliable budget is understanding the work. A schedule of works should explain the proposed tasks and standard of finish, while quotes should make inclusions and exclusions clear. Professional investigations may be needed before some elements can be priced sensibly.
Contingency does not replace that preparation. If the heating system has not been assessed or an important area could not be inspected, identify the uncertainty explicitly. A single reserve line should not hide the fact that a major part of the job is still undefined.
Ask the team to distinguish known work, provisional allowances and genuinely unexpected items. Those categories help you understand the budget more clearly than a total accompanied by a general assurance that there is some spare money.
The amount depends on the project
There is no single contingency figure that is automatically right for every house. The condition, scope, level of investigation and complexity of the work all matter. A light refurbishment with well-understood services is different from a project involving substantial alterations and inaccessible building elements.
The useful question is why the proposed allowance is appropriate for this project. Ask what the team considers uncertain and how the amount has been arrived at. If important information is missing, more investigation may be preferable to simply increasing a percentage.
Keep the contingency separate from planned upgrades. A more expensive kitchen chosen after the budget is agreed is a scope decision. An unexpected necessary repair is a different type of change, even if both ultimately require additional funds.
An illustration of how it affects the numbers
Imagine an illustrative refurbishment with £24,000 of specified work and a £4,000 contingency. The works-related funding allowance is £28,000, not £24,000. This is a teaching example rather than a recommended percentage or an Oakridge quote.
If an additional necessary repair costs £2,500 and is approved, the reserve falls to £1,500. The project update should show the original allowance, the approved use and what remains. That makes it possible to judge whether the remaining reserve still fits the outstanding uncertainty.
If further work then exceeds the reserve, the project needs another decision. The existence of a contingency does not guarantee that it will cover every eventuality. Agree in advance how a potential shortfall would be reported and what options would be considered.
Decide who can approve spending
For a hands-off investor, the approval process matters. You may want the team to handle minor decisions within an agreed scope, while reserving approval of material changes. The agreement should describe the limits and how requests will be made.
A useful change request explains the issue, why the work is needed, the proposed solution, the price and any timing consequence. Where there are reasonable alternatives, it should explain them. Photographs and professional advice can support the request without replacing the written decision.
Avoid relying on a hurried phone conversation as the only record of a significant change. Confirming the decision in writing helps everyone work from the same understanding, especially when several trades and advisers are involved.
Track time as well as money
Additional work may extend the programme. Even if the repair itself fits within the reserve, extra ownership or finance costs may arise elsewhere in the budget. Check the whole project rather than assuming that the contingency line absorbs every effect.
For example, a delayed finish may alter the anticipated marketing date. That could extend insurance, utilities or borrowing costs under the actual arrangements. The amounts need to be assessed for the particular project rather than borrowed from a generic example.
Reporting should therefore connect changes in scope with both expenditure and programme. A reserve balance is useful, but it is not enough if the expected exit date has moved and the wider cash-flow plan has not been updated.
Review unused money at the end
If the reserve is not fully used, the final account should show that. How the resulting proceeds are distributed depends on the agreed structure, fees, finance and tax position. Do not assume that every unspent pound translates directly into a personal investment return.
Before completion, keep the money available for its intended purpose. Treating it as already earned can create pressure to avoid necessary work or leave the project short when a genuine issue appears.
A useful question for your next conversation
Ask: “What could change this budget, and how would we deal with it?” The answer should cover the investigation already completed, the remaining uncertainties, the reserve, the approval process and the reporting. That is a more meaningful conversation than asking only whether the quote is fixed.
Our investor guide explains the main budget terms, and the Oakridge process shows where the scope and decisions are agreed. A realistic contingency helps make the plan understandable; it does not turn an uncertain project into a guaranteed outcome.