How Volve builds a traceable bill of quantities

A bill of quantities is a claim about the drawings and the model. Most bills don’t say what the claim rests on.

Take a slab measured at 1,860 square metres. It was right on revision B of the structural plan and wrong on revision C, where a core moved. The bill carried the number, not the revision. When the estimate and the model disagreed, nobody could say which was current without measuring again. The client’s bill, a subcontractor’s bill, a BIM schedule and an AI take-off share the same flaw: a number without its basis. The claim can be checked, as the checklist on how to check a bill of quantities says, but only if the basis is there to check against.

What traceable means

A quantity is traceable when you can open the sheet, schedule or model element it came from, see the revision it was measured on, and see the method of measurement applied. The test is practical. If a reviewer asks where 1,860 square metres came from and the answer takes more than a click, it isn’t traceable.

Traceability is what lets someone who did not measure a number use it: the estimator who prices it, the buyer who levels subcontractor bids against it, the site team that inherits it after award.

Four kinds of quantity

Every line in a Volve bill is one of four things, and the bill says which.

Measured. Taken off the drawings or the model, traced to the sheet or the element.

Counted. Items counted from schedules or drawings: doors, piles, fittings.

Conditional. Measurable once an open point is answered. A pile length that depends on a founding level the ground investigation hasn’t fixed. The method is known; one input isn’t.

Not quantified. The documents don’t support a number yet. It needs your input or an assumption.

The four are kept apart. A measured quantity and an assumed one are different kinds of number, and one total that mixes them hides the difference that matters most when pricing.

The fourth category matters most. A bill that admits what it did not measure is more useful than one that fills the gap and moves on, because the gap is where the pricing risk sits. An estimator reading a bill with twelve open items knows twelve things to settle before the price is committed. An estimator reading a bill with none knows nothing, including whether there were any.

Open points, and who closes them

Every conditional or unquantified line is an open point, and the team decides how it closes. Answer it from your own information: a survey you hold, a depth you know from the last job on that ground, a decision on extent. Or let Volve assume, in which case the assumption is marked as an assumption, carries its basis, and stays visible in the bill until something better replaces it.

“Assumed” is a legitimate state for a quantity as long as it is visible. An assumption dressed as a measurement is not. Volve measures what the documents support; the decisions stay with the team.

In the Three-Loop Bid Method this is loop two’s assumption baseline, every assumption tied to its source or marked open, and the bill is that baseline for quantities.

What comes out, and when you use it

The bill is a working document in Volve, where the team reviews it together with the trail attached to each line, or exported to Excel to price where you normally price. Lines are coded to the specification or to the measurement standard you choose: NS 3420, NRM2, CESMM 4.

Three moments in a tender week. Checking the client’s bill before pricing, with the measured quantities beside the client’s and the differences listed. Building quantities where there is no bill. Seeing what an addendum moved, re-measured from the revised sheets with the moved lines flagged.

What it doesn’t do

It does not set rates. It does not make the bid-or-no-bid call. It does not replace the estimator’s read of the ground, the market or the client. Treat every line as a finding to review; that is what the status is for.

The standard

A bill should show its working. That is the whole of it, and it applies to ours first. The full picture is on the cost and estimating page, the patterns bills fall into are in the Top 7 quantity gaps note, and the quickest way to judge the standard is to see Volve on a tender like yours.