What the clause must contain
Four elements, and omitting any one makes it inoperative. They cover the trigger, the recording, the price and the decision.
A definition of a discovery, precise enough not to cover every deviation.
An obligation to stop and report, before any intervention on the element found.
A procedure for characterisation and pricing, with a time limit.
A decision rule, stating who decides, within what period, and what happens absent a decision.
That last point is most often omitted, and it is what stalls projects.
| Element of the clause | What it fixes | Consequence if missing |
|---|---|---|
| Definition of a discovery | What triggers the clause | The clause never triggers |
| Recording procedure | How the finding is established | The clause remains a dead letter |
| Method of pricing | How the extra is costed | The price is negotiated under pressure |
| Decision rule | Who decides and within what time | The works stop during the argument |
How to define a discovery
The exercise is to delimit without stifling, and two excesses threaten. A clause too wide and one too narrow fail equally.
Too broad a definition transfers all contingency to the client. If every deviation is a discovery, the contractor bears no estimating risk at all.
Too narrow a definition makes the clause unusable. If only extreme cases qualify, real situations fall outside it.
The useful test is prior verifiability: a discovery is an element that could not have been established by the investigations carried out, given their agreed nature.
That test links the clause to the written assumptions in the quotation, covered in the article on measurement in renovation.
The procedure to write
Five steps, each with its time limit.
The record, documented in writing and with photographs, with location.
The report, within a short period, to a designated contact.
Technical characterisation, distinguishing what must be dealt with from what may be.
Pricing, on the basis of contract unit rates where they exist, or by an agreed method.
The written decision, with its effects on price and programme.
Any step without a written time limit becomes a potential stoppage, as the article on periods and interruptions explains.
The default decision rule
The technical point distinguishing a good clause from a decorative one. It concerns how the price of discovered works is fixed.
What happens if the client does not decide within the period allowed.
Three options, to be chosen consciously.
Stopping the works at the client's cost, which prompts a decision but may prove harsh.
Continuing on unaffected areas, which preserves progress but complicates organisation.
A decision deemed taken in a given direction, which is effective but presupposes that the direction chosen is reasonable.
None is inherently better. What matters is that one option is written, failing which the project stops without anyone clearly bearing the cost.
The error that empties the clause
It is frequent and it nullifies everything. A clause without a recording procedure remains a dead letter.
Executing before deciding. Under programme pressure, the contractor deals with the discovery to avoid losing time, and the question of price arises afterwards.
The clause then becomes pointless, since its purpose is precisely to put decision before execution.
Two simple safeguards: the obligation to stop must be explicit, and the clause must provide that work carried out without a written decision gives no right to additional payment.
That second stipulation also protects the contractor, by deterring them from starting work they might not be paid for.
The link with the contingency
A point of connection making the clause budgetarily effective. It is read together with the contingency allowed in the quotation.
The contingency is what funds discoveries, as the article on pricing with a contingency explains.
The discovery clause is what organises its use. One without the other is incomplete: a contingency without procedure is consumed without decision, a procedure without contingency has nothing to draw on.
What this means for a professional
Four rules.
Define a discovery by prior verifiability, tied to the investigations actually carried out.
Write a default decision rule, even an unwelcome one, rather than leaving none.
Provide that work carried out without a decision gives no right to additional payment.
Tie the clause to the contingency, so the procedure has funding.
This article sets out drafting principles at the date of checking and serves professional orientation. It does not constitute legal advice and does not replace assessment of the individual case.