Variation claims in construction are where many projects quietly gain or lose their margin. A contract signed at one figure rarely finishes at exactly that figure, and the difference is usually made up of variations: changes to the scope, the documents or the conditions under which the work is carried out. This guide explains how variations and delay claims should be priced, why they so often end in dispute, and how an independent assessment of a claim protects builders, owners and developers alike.
What counts as a variation under a construction contract
A variation is any change to the scope of works described in the contract documents. Common examples include design changes issued after the contract is signed, substituted materials or finishes, and additional works requested by the owner. Latent conditions, such as rock, contamination or hidden structural defects that could not reasonably have been foreseen, are treated as variations under many contracts as well. Most standard form contracts used in Australia set out a specific procedure for directing, pricing and approving variations, and following that procedure matters as much as the pricing itself.
Not every extra cost is a variation. Work that was always required by the documents, even if the builder did not allow for it, is generally not claimable. Much of the disagreement around variations comes down to this boundary: whether the work in question was a genuine change, or something the contract price should already have covered. That is a question answered by careful reading of the drawings, the specification and the tender documents, rather than by negotiation strength.
How a variation claim should be priced
A properly priced variation is built up the same way an estimate is: measured quantities, current rates and documented assumptions. Where the contract contains a schedule of rates, those rates generally apply. Where it does not, the price should be demonstrably consistent with the market. A defensible variation claim typically includes the elements below.
| Element | What it covers |
| Direct costs | Measured labour, material and plant for the changed work, priced at rates consistent with the contract or the current market |
| Omissions | Credit for any work in the original scope that is no longer required, measured on the same basis as the additions |
| Preliminaries | Time-related costs where the change extends the program, such as supervision, site facilities and scaffold hire |
| Margin | Overheads and profit applied in accordance with the contract, shown separately rather than absorbed into rates |
| Substantiation | The drawings, directions, site records and correspondence that establish the entitlement, not just the amount |
The weakest variation claims are round-number lump sums with no measurement behind them. They are difficult for the other side to assess, easy to reject, and hard to defend if the matter escalates. A claim built from measured quantities and current rates, with the entitlement documented, tends to be resolved faster and closer to its full value.
Delay claims and time-related costs
Delay claims deal with time rather than scope. A project sometimes runs longer for reasons the contract puts at the owner’s risk, such as late design information, delayed access or variations themselves. When that happens, the builder may be entitled to an extension of time and, depending on the contract, delay costs for the extended period.
Pricing a delay claim means establishing two things: how long the delay actually was, demonstrated against the construction program, and what it genuinely cost. Delay costs are largely time-related preliminaries: supervision, site sheds, cranage, scaffold and other week-by-week costs that continue whether or not productive work is happening. Because these accrue gradually, they are commonly underclaimed by builders and just as commonly overclaimed when calculated as a flat daily rate without substantiation. Site records, the program and the preliminaries build-up in the original tender are the evidence that separates a strong claim from a weak one.
Why variation disputes escalate
Pricing left until the end
Variations priced months after the work was done rely on memory instead of records. Agreeing the price, or at least the pricing basis, before or as the work proceeds keeps the final account manageable and the relationship workable.
Procedure not followed
Most contracts require variations to be directed in writing and claimed within set timeframes. Work done on a verbal instruction, or claims submitted out of time, can compromise an otherwise legitimate entitlement. Keeping the paperwork current is not administration for its own sake; it is what preserves the claim.
Neither side has an independent measure
When a builder’s claim and an owner’s assessment are both unmeasured opinions, the gap between them is settled by negotiating power. A measured assessment gives both parties a common reference point, which is usually what turns a dispute back into a discussion.
The value of an independent assessment
An independent quantity surveyor can act for either side of a variation or delay claim: preparing and substantiating a claim for a builder, or assessing a submitted claim for an owner, developer or financier. The approach is the same in both directions. The changed work is measured, rates are applied consistent with the contract and the current market, the time claimed is tested against the program and the records, and the result is documented so it can be reviewed line by line. The Australian Institute of Quantity Surveyors (AIQS) sets professional standards for exactly this kind of cost assessment, and an assessment prepared on that basis carries weight in negotiation and, if it comes to it, in formal dispute resolution.
The earlier that independence is introduced, the cheaper it is. A measured review of a contested variation costs a small fraction of what the same disagreement costs once lawyers are involved, and most claims assessed on a measured basis never get that far.
Order an independent variation or delay claim assessment from Accent Estimating.
Frequently asked questions
What is the difference between a variation claim and a delay claim?
A variation claim relates to a change in the scope of the works and is priced from measured quantities and rates. A delay claim relates to the project running longer for reasons the contract allocates to the other party, and is priced from time-related costs over the demonstrated delay period. One change can give rise to both.
Can a builder claim for work not covered by a written direction?
It depends on the contract, and most contracts require written directions for variations. Claims based on verbal instructions are harder to establish, which is why contemporaneous records, confirmation emails and site diaries matter so much. Specific situations should be checked against the contract terms and, where necessary, with legal advice.
How are variation rates determined if the contract has no schedule of rates?
Generally on the basis of reasonable market rates for the work at the time it is carried out. An independent assessment establishes these from measured quantities and current pricing data, which is considerably more defensible than a negotiated lump sum.
What records support a delay claim?
The construction program and its updates, site diaries, photographs, correspondence showing the cause of delay, and the preliminaries build-up showing what the time-related costs actually are. Claims supported by records are assessed on evidence; claims without them are assessed on scepticism.
Who can assess a variation claim independently?
A quantity surveyor or professional estimator with no stake in the outcome. Because the assessment is based on the contract documents, drawings and records, it can be prepared for projects anywhere in Australia without a site visit in most cases.