Progress payments and quantity tracking: how much of the work is actually done

A progress payment isn't a reward for time elapsed or general activity on site, it's a claim for work actually completed, measured against quantities and unit rates fixed in the contract. The percentage figure in a payment application should trace back to specific measured quantities, not an overall visual impression of how far along the project looks.

This distinction matters most on items that are hard to see once complete, reinforcement inside a poured slab, waterproofing under a finished floor, or conduit inside a wall, where a payment claim depends on measurements and photographs taken before the work was covered, not on what's visible at the time of the payment application.

A contract that defines measurement method and required evidence clearly, before construction starts, prevents most disagreements about what counts as 'complete' for payment purposes, leaving it implicit is what causes disputes later.

Once reinforcement is covered by poured concrete, or a service is buried behind a finished wall, there is no practical way to re-verify quantity or quality without destructive investigation. This is why measured, photographed sign-off before covering is not optional documentation, it is the only evidence that will exist for that item for the life of the building.

The practical workflow: a specific checklist item for every concealed-work stage, requiring photographs against a scale reference and a written measurement, signed off by both the contractor and the supervising party before the next stage proceeds. Skipping this under schedule pressure is a common mistake with an expensive fix if a dispute arises later.

This evidence also protects the contractor, not just the client, a properly documented concealed-work stage is the contractor's best defence if a later dispute questions whether reinforcement or waterproofing was actually installed to specification.

A common source of disagreement is partial completion on a single line item, a wall that's framed but not yet finished, for instance. Contracts should specify whether payment for that item is all-or-nothing on completion, or proportional to sub-stages (framing, first fix, finish), because the two approaches produce very different cash flow and very different incentives.

Materials delivered to site but not yet installed are another frequent grey area, some contracts allow partial payment for stored materials against a delivery note and proof of ownership, others don't recognise them until installed. Neither approach is inherently wrong, but it needs to be explicit in the contract rather than negotiated ad hoc at each payment cycle.

Retention, a percentage withheld from each payment until final completion or the end of a defects liability period, should also be clearly defined from the start: the percentage, the release trigger, and the timeline, so it isn't a point of friction reopened at every application.

A payment application prepared solely by the contractor and accepted without independent verification puts the client in a weak position if the figures are later disputed. A supervising architect or engineer reviewing and countersigning each application against site records is the standard safeguard, and it protects the contractor as much as the client by giving the figure independent credibility.

This review should be a genuine measurement check against the evidence trail described above, not a formality, comparing the claimed quantity for each line item against photographs, measurements, and delivery records from that period, not just checking that the total looks reasonable.

Where this independent check happens consistently, payment disputes are rare, because both sides are working from the same evidence rather than reconciling two different mental pictures of progress after the fact.

A measured quantity breakdown by line item, not just a summary percentage and total, a client should be able to see which specific quantities the claimed percentage is built from, not just trust a single top-line figure.

Photographic evidence for any concealed work claimed in that period, dated and referenced to the specific location on the drawings, so it can be checked against both the contract quantities and the site log.

A running comparison against the original schedule of values agreed at contract signing, not a renegotiated baseline, so that drift between the original plan and the current claim is visible rather than gradually normalised over the course of the project.