A remeasurement contract prices work at fixed rates but pays for actual quantities built, verified on site rather than assumed at tender. The Bill of Quantities issued at tender stage is treated as provisional: quantities get adjusted throughout the project, and the final account is settled on measured, as-built quantities at the agreed contract rates. For anyone forecasting interim payments, that single fact changes everything about how cash flow gets modelled.
TL;DR:
- Remeasurement contracts rely on provisional or approximate Bill of Quantities, causing final costs to depend on actual onsite measured quantities rather than estimates.
- Joint measurement and clear rules before valuation are essential for honest remeasurement processes, reducing disputes over quantity differences.
- Variation clauses address large quantity changes, but proper documentation and rate review mechanisms are necessary when site conditions differ from estimations.
- Digital takeoff tools aligned with measurement standards decrease the risk of disputes by providing auditable, traceable quantity data from the start.
- Choosing remeasurement contracts is advisable when site conditions or design uncertainty dominate, but lump sum agreements suit finalized, well-defined projects.
Table of Contents
- What are remeasurement contracts and how do they use a BoQ?
- When should you choose a remeasurement contract?
- How does the remeasurement process actually work?
- How do contracts treat large quantity variations?
- Dealing with missing items, provisional sums and variations
- What causes disputes, and how do you control them?
- A practitioner's view on measurement discipline and digital records
- Reduce remeasurement risk with structured digital takeoffs
- Sources
What are remeasurement contracts and how do they use a BoQ?
Two terms get confused constantly in commercial correspondence: remeasurement and admeasurement. Remeasurement describes the whole procedure of re-checking completed work against the drawings and the BoQ. Admeasurement is narrower. It's simply the numeric gap between what was estimated and what was actually measured on site, as the Designing Buildings Wiki entry on remeasurement sets out clearly. Mixing the two up weakens a claim the moment a contract administrator spots the imprecision.
NRM2 is the reference standard most UK practitioners work from. It sets out the rules for detailed measurement, covers how preliminaries and non-measurable items get treated, and explains when an approximate BoQ is the right tool rather than a firm one.
The distinction between the two BoQ types matters commercially:
- Firm BoQ: quantities are considered accurate and fixed, used where design is substantially complete.
- Approximate BoQ: quantities are provisional estimates, used where design detail is insufficient at tender, and the whole bill is subject to remeasurement.
A BoQ isn't just a quoting document. It's the pricing and payment mechanism that carries the contract rates from tender through to final account, which is exactly why approximate quantities carry more variation risk than a lump-sum equivalent.
When should you choose a remeasurement contract?
Remeasurement suits specific circumstances rather than every job. It works well where design is incomplete at tender, where ground conditions are uncertain, or on civils, groundworks, and repair contracts where quantities genuinely cannot be pinned down until excavation starts. NEC Option B and JCT with quantities are the standard-form routes most commonly used for this unit-price approach.
Weigh the trade-offs before committing to the form:
- Employer advantage: pays only for work actually done, avoiding overpayment on inflated tender quantities.
- Contractor advantage: rate certainty is locked in early, even if total quantities shift.
- Employer disadvantage: budget certainty is weaker, since the final cost isn't fixed until practical completion.
- Contractor disadvantage: cash flow forecasting is harder when quantities move significantly from tender assumptions.
- When lump sum wins: choose it once design is frozen and quantities are genuinely known, since remeasurement's flexibility becomes an unnecessary administrative overhead.
Ask yourself one question before drafting the contract: is the uncertainty in the design, or in the site? If it's neither, a lump sum is usually the leaner option.
How does the remeasurement process actually work?
Tender quantities are estimates from the design available at the time, nothing more. Every party to the contract should treat them as a starting point, not a promise. Once work is underway, the mechanics follow a fairly consistent rhythm across most standard forms.
- Quantities are measured jointly by the contractor's surveyor and the contract administrator or employer's QS, ideally at agreed intervals rather than ad hoc.
- Interim certificates are compiled by applying contract rates to the quantities measured up to the valuation date, not the quantities originally billed, as explained in detail in CIS for subcontractors: registration and deductions explained.
- Measurement records, marked-up drawings, and site diaries form the evidence base for each valuation.
- The final account consolidates all interim remeasurements into one settled total, with retention released according to the contract's timing provisions.
Pro Tip: Agree the measurement rules and rounding conventions with the other side before the first valuation, not after a dispute forces the issue. A five-minute conversation at kick-off saves weeks of argument at final account.
Joint measurement is the safeguard that keeps this whole process honest. Skip it, and you're relying on one party's word against another's months later, with no contemporaneous record to settle the argument.
How do contracts treat large quantity variations?
Variation-in-estimated-quantity clauses exist precisely because approximate BoQs invite disagreement once as-built quantities diverge from tender assumptions. FAR 52.211-18, used in US government contracts, is the clearest worked example: if actual quantities vary beyond a set threshold above or below the estimate, either party can demand an equitable adjustment. FIDIC and NEC carry equivalent, though differently worded, provisions.
The practical effect depends heavily on what else is in the contract.
- A VEQ clause can be overridden where differing site conditions or a change/variation clause better fits the actual cause of the quantity movement.
- Set clear notice windows for raising a variation claim; late notices weaken otherwise valid claims.
- Build in a rate review mechanism for cases where the character of the work itself changes, not just its volume.
- Document any shift in working method, sequencing, or plant requirement alongside the quantity change, since a rate review needs more than "we dug more than expected" to succeed.
Dealing with missing items, provisional sums and variations
Omissions from the original BoQ surface constantly once excavation or strip-out begins, and how they're handled shapes the final account far more than most people expect.
- Record the omitted item the moment it's identified, with a description, location reference, and photographic evidence attached.
- Value provisional sums against actual instructions issued, not the sum originally allowed, since provisional figures are placeholders rather than caps.
- Instruct additional items formally through the contract's variation procedure before pricing them, never verbally on site.
- Price new items using the nearest analogous BoQ rate where possible, adjusted for genuine differences in condition or quantity.
- Keep a running schedule of all instructed variations alongside the measurement records, so the final account reconciles without a scramble at handover.
Contractor-designed elements need particular care here, since the BoQ rate assumed a specific design intent that a later variation may have quietly changed.
What causes disputes, and how do you control them?
Most quantity disputes trace back to a handful of recurring triggers: BoQ errors baked in at tender, late or infrequent measurement, rates that don't stretch to cover unforeseen conditions, and genuinely differing site conditions that nobody priced for. Practical guidance on NEC Option B flags exactly these as the most common sources of claims on remeasurable contracts.
The controls that actually work are unglamorous but effective:
- Joint measurement with both parties signing off, every time.
- Photographic evidence and annotated drawings kept contemporaneously, not reconstructed later.
- NRM2-compliant takeoff methods applied consistently from tender through to final account.
- Contemporaneous site diaries cross-referenced against valuation dates.
Adjudication suits fast, binding interim decisions during the works; arbitration or litigation tend to come into play only when final account positions are entrenched and the sums are significant enough to justify the cost. Courts and adjudicating boards routinely ask whether a large variation was foreseeable, and whether a differing site conditions clause should govern the remedy instead of the VEQ mechanism.
A practitioner's view on measurement discipline and digital records
Clear measurement rules, agreed before work starts, resolve more disputes than any clause redrafting exercise ever will. Most quantity arguments I've seen dissected in commercial reviews come down to one side having a contemporaneous record and the other having a recollection. That imbalance decides the outcome before anyone opens the contract.
Structured BoQ output, generated consistently and traceably, supports joint measurement far better than a spreadsheet rebuilt from memory after the fact. When the baseline takeoff is auditable from the start, interim valuations move faster because nobody's arguing about what the original quantity actually was.
Keep tender quantities within realistic tolerances of what the drawings actually show, and keep every subsequent measurement event logged against that baseline. It's a small discipline that pays for itself the moment a final account gets contested.
— Michael
Reduce remeasurement risk with structured digital takeoffs
Approximate BoQs carry variation risk by design, and the practical fix is not better guesswork at tender. It is a measured baseline you can defend at final account. Some platforms build NRM2-aligned BoQ output directly from architectural drawings, with every quantity and revision logged in an audit trail that stands up when a valuation gets challenged.
That structure translates into fewer arguments over what the tender quantity actually was, clearer evidence at interim certification, and less time spent reconstructing measurement history months after the drawings changed. For firms tendering approximate BoQs regularly, that consistency lowers the risk baked into every remeasurable line item. Certain software keeps the quantity surveyor's professional judgement in charge throughout. It flags and structures; you sign off. If measurement disputes are eating into your final account timelines, view how Quantiflow's takeoff engine works and request a demo to see your own drawings turned into a structured, defensible BoQ.
Sources
For deeper reference, consult NRM2's detailed measurement rules, guidance on BoQ formats, and variation-in-quantity case analysis.
- NRM 2: Detailed measurement for building works (RICS)
- Construction Claims for Variation in Quantity | Long International
- Bill of Quantities in Construction: How a BOQ Works and Why It Matters
- Remeasurement (Designing Buildings Wiki)