Understand construction pricing on VEXORS

Construction bills carry vocabulary that general procurement never needs: provisional sums, PC sums, attendance, dayworks, remeasurement, lump-sum sections. VEXORS models each of these as a first-class thing rather than a note in a description field, which is what keeps bids comparable and the client bill honest. This page is the reference for all of it, for both sides of a tender.

The five line types

Every line on a construction bill carries a Line type. The buyer sets it when building or importing the BoQ; suppliers see it on every line they price.

Line type	What it means	How it is priced
Measured	The normal case: work measured from drawings with a firm description and quantity.	The supplier enters a unit rate; the line total is rate times quantity. Only measured lines compete on price in scoring.
Provisional Sum	An allowance for work that cannot be fully defined yet (the classic example: an unresolved scope pocket the consultant priced as a placeholder).	The amount is carried as stated; it is spent, adjusted, or omitted as the work becomes defined. Not a competitive price.
PC Sum	A prime cost sum: an allowance for materials or goods the buyer will select later (sanitary ware, tiles, ironmongery). A Nominated subcontractor can be named on the line.	The sum itself is fixed; the supplier adds their Attendance % and Profit % on top (see below). Those percentages are the competitive part.
Preliminaries	The cost of running the site: supervision, setup, insurances, temporary works.	Priced as its own lines or handled at project level through the Preliminaries modes in Pricing settings.
Daywork	Labour, plant, or materials to be charged at agreed rates for time actually spent, used for work that cannot be measured in advance.	The supplier quotes the rates; the spend depends on hours actually instructed.

PC sums: attendance and profit

A PC sum's amount is not the supplier's to change: the buyer fixed the allowance. What the supplier controls, and what you compare between bids, are two percentages entered on the line:

• Attendance %: the cost of receiving, storing, handling, and coordinating the supplied goods.
• Profit %: the supplier's margin on the sum.

The line total is the sum multiplied by one plus the two percentages combined. A 100,000 PC sum with 5% attendance and 3% profit totals 108,000. Two bids carrying the same PC sum can differ only in those percentages, which is exactly the comparison the evaluation shows you.

Quantity basis: firm, provisional, rate-only

Independent of line type, each line has a Quantity basis:

• Firm quantity: a quantity the buyer stands behind; priced as rate times quantity.
• Provisional quantity: an estimate the buyer may adjust before award; suppliers see it labeled and price the rate knowing the volume can move.
• Rate only: no quantity at all; the work is remeasured on site. Suppliers quote a unit rate, the line is excluded from bid totals with the count disclosed, and the client bill shows the marked-up rate with "measured on completion" instead of a fabricated amount.

Lines with structured dimensions (an opening, a penetration, a linear run) can also carry a Dimension shape, so the dimensions travel as fields rather than being buried in the description. The import guide covers how each basis arrives from a workbook, including rate-only schedule detection.

Bid response format: itemized, or one price for the section

Each section of a construction bill carries a Bid response format that tells suppliers how to price it:

• Itemized required: "Suppliers must price every line in this section individually." Every line gets its own rate, and lines compete on price in scoring.
• One price for the section (breakdown required): "Suppliers give one price for this whole section and a priced breakdown behind it. The breakdown gives you rates to value variations against later."

The second format is how lump-sum trades are tendered without losing the rates. The supplier enters a Lump-sum amount, which is the one figure that governs, and prices the lines beneath it as the breakdown. A Reconciliation panel shows the Build-up total against the Section price and reads Balanced, Over by, or Short by; any difference goes into an Adjustment (discount or uplift), which the panel can fill in one click. A bid cannot be submitted while a required lump-sum section is unpriced or unreconciled.

Part bids

Under Conditions of Tender, the buyer states the Part bids rule for the whole request:

• Full scope required: every item must be priced.
• Part bids accepted: suppliers may bid for part of the scope, whether a reduced quantity, an item they are not bidding, or a whole section they decline.
• Not stated: the buyer has not declared a rule.

Where part bids are accepted, a supplier's Decline this section is honoured and the bid total covers only what they priced. Where full scope is required, an unpriced line blocks submission. The AI evaluation reads the declared sections and unpriced scope back to the buyer in its checks before award, so a part bid is never compared to a full bid as if the two covered the same work.

How scoring treats all of this

AI Scoring's job is a fair price comparison, so it separates what genuinely competes from what merely adds up, and it tells you what it did in the disclosures panel of the run's audit view:

• Provisional sums, PC sums, preliminaries, and daywork lines are excluded from competitive price scoring but included in bid totals, and the disclosure states how many lines that covered.
• A section priced as one figure is compared at section level, not per line, and lines inside it are excluded from per-line price comparison. Bid totals say how many lump-sum sections they include.
• Rate-only lines are excluded from totals, with the count disclosed.
• Your own estimates only influence scoring within sane bounds, and a sole-bidder situation is disclosed in the same panel rather than silently scored.

The full evaluation workflow is in Review bids and AI Scoring.

Measurement standards

The Measurement standard on a construction bill declares which rules your quantities follow: POMI, CESMM4, NRM2, or SMM7. It does not change any arithmetic on VEXORS; it tells every bidder how the quantities were measured, so their rates assume the same measurement conventions yours did. Pick the standard your quantity surveyor actually used, and keep it consistent across the packages of one project (copying commercial terms from the master does this for you).

Retention, advance payment, and bonds

The Construction bill toggle also carries the commercial securities every subcontract price depends on:

• Retention %: the share of each payment held back until completion or the end of the defects period.
• Advance payment %: the mobilization payment made up front.
• Bid bond and Performance bond: each defined as a percentage or a fixed amount.

These are declared on the master and copied into packages so every trade prices against the same terms. A supplier pricing 10% retention and no advance quotes differently than one pricing 5% retention with 20% advance; putting the terms in the structure is what makes their rates comparable.

The sub-tender chain: when the supplier becomes a buyer

Construction supply chains run deeper than one level. A subcontractor who wins, or is bidding for, a large package often buys out parts of it themselves. VEXORS models that directly:

• Scale While preparing a bid, a supplier can select lines of the bill they are pricing and use Create Sub-Tender to carve them into their own trade package, floated to their own suppliers as a normal tender.
• As sub-tender bids arrive, the supplier can mark one Carry this price per line: the carried price rolls up onto their own bid so they can see their margin while they finish pricing the main bid. Carried prices show with a Carried badge in their roll-up, and the roll-up shows the margin at current and suggested prices. Sub-tender bids in a currency the supplier has no rate for are shown unconverted with a warning, never silently converted.
• A sub-tender cannot be awarded until the supplier's own bid on the main contract is awarded. Nobody commits to a sub-subcontractor for a job they have not won; carrying a price tracks the margin in the meantime.
• A sub-tender is itself a request, so its bidders get the same structured process, and it cannot be split again into trade packages.

What good looks like

• Line types match reality: allowances typed as provisional or PC sums, not disguised as measured lines with invented quantities.
• PC sum attendance and profit are compared deliberately at evaluation, because they are the only competitive part of those lines.
• Sections that the market prices as a whole are set to one price with a breakdown required, so you keep the rates without forcing a false itemization.
• The part-bids rule is stated, so no supplier declines a section the buyer assumed was covered.
• The measurement standard is declared once, on the master, and never varies between packages of the same project.
• Retention, advance, and bonds are set before splitting, so no trade tenders on terms you did not intend.
• Suppliers read the scoring disclosures the same way buyers do: knowing which of your lines competed on price tells you where sharpening your rates actually matters.

Run your next tender structured