How to read a priced bill of quantities: structure, columns and warning signs

A well-structured priced bill is organised in three levels of hierarchy, always in the same order.

• Level 1, the package: a trade or a coherent grouping of works, groundworks and external works, concrete frame, roof structure and covering, and so on. Each package is the subject of a separate contract with a different contractor.

• Level 2, the sub-package: a subdivision of the package by phase of execution or by nature of the work, within the frame, for instance: foundations, superstructure, stairs, sundries. How the package is broken down determines how legible the monthly valuations will be.

• Level 3, the individual item: a single line with a precise description, a unit, a quantity and a unit rate. This is the level at which the quantities are checked against the drawings and the rates against the market.

A priced bill with no sub-packages, going straight from package to item, signals a take-off that is not detailed. One with too many levels, four or five, is hard to use at tender and on site. Three levels is standard good practice.

The column to read first for a quick check is the package subtotals. Each one should be compared with market rates for the building type and the region concerned. A concrete frame at 150 €/m² on an apartment building in the Paris region is suspect; the usual range is 250 to 320 €/m². A gap of that size signals either an error in the take-off or a very atypical project that deserves an explanation.

Here is a priced bill for the concrete frame of a scheme of eight dwellings, around 890 m² habitable area. The annotations in the last column flag the points to check.

Only one warning appears in this example: item 02.02.01, concrete walls at 145 €/m², sits at the top of the range. That rate may be explained by special formwork, fair-faced finishes or curved shapes, or by a high density of reinforcement, and it deserves a check with the architect. The overall package rate of 267 €/m² is consistent with the market range for this type of project.

ℹ Two-stage checking: the overall rate, then line by line Reading a priced bill efficiently happens in two stages. First the overall rate: if the package rate per square metre falls inside the market range, the estimate is probably coherent and there is no point checking every line. Then, if the rate is abnormal, more than 15 % above or below, go into the detail line by line to find the anomaly. That approach concentrates the checking time on the packages that deserve it, typically the three or four that carry 70 to 80 % of the total cost: frame, façades, mechanical services and finishes.

Some units are more transparent than others. Square metres, linear metres and cubic metres can be checked directly against the drawings. The "item" or "lump sum" unit, by contrast, hides the quantities behind an opaque global price. A priced bill with a lot of lump sums is hard to verify and hard to compare against the contractors' tenders.

Lump sum items below 2 000 € are generally acceptable, being minor pieces of work. Lump sums above 10 000 € deserve to be broken down, or at the very least justified by a calculation note.

• Tiling in linear metres instead of square metres: a frequent entry error that produces a total 40 to 80 times too low depending on the tile size.

• Windows in square metres instead of numbers: if the rate is not consistent with the area of the window, the total will be wrong.

• Insulation in cubic metres instead of square metres: produces a total 10 to 20 times too high depending on the thickness, unless the rate has been adjusted.

• Painting measured gross instead of net: paint is measured on the surface actually to be painted, with openings deducted; measuring gross overstates by 15 to 25 %.

The main purpose of a priced bill is not to present a budget to the client, it is to serve as the reference against which the tenders are compared. The comparison works at three levels.

• Level 1, package totals: if a contractor's tender is more than 15 % below the priced bill subtotal on a significant package, that signals a possible under-priced tender. More than 20 % above signals an over-priced one.

• Level 2, sub-package subtotals: shows which phase the contractor is abnormal on, under-priced on foundations but coherent on the frame, for instance.

• Level 3, line by line: used only on the items that triggered an alert at level 1 or 2. It establishes whether the anomaly comes from a rate or from a different quantity, which may mean the contractor is reading the drawings differently.

ℹ Different quantities in the pricing schedule: watch the lump sum In a lump sum contract, a contractor returning a pricing schedule with quantities different from the priced bill but a coherent overall total is entitled to have done its own measurement. Under a lump sum the contractor commits to a result, the completed works, in accordance with the drawings and specification, for the lump sum, not to the quantities in the priced bill. That distinction is fundamental: a contractor that allowed for less material cannot claim an extra if its quantities were understated. Equally, it cannot deliver less work on the grounds that its quantities were overstated.

These are the signals that should trigger a deeper check or a request for explanation from the economist.

A priced bill reads in three levels: package, sub-package, item. The quick check starts with the overall rate per square metre for each package; if that is consistent with the market, there is no need to go into the detail. The columns to watch are the date of the estimate, the source of the drawings, the units, lump sums above 10 000 € are suspect, and the rates on the significant items. The five critical signals are external works missing, contingency below 5 %, an overall rate more than 15 % below the range, items outside the works absent, and reference drawings not named. At tender assessment the priced bill serves as the reference at three levels: package totals, then subtotals, then line by line only on the abnormal items.

The nature of the figures quoted

The percentages and amounts quoted on this page are orders of magnitude for framing, not measurements. They illustrate mechanisms and proportions, and they substitute neither for a tender exercise nor for an estimate prepared on drawings.

• Priced bill, pricing schedule, specification: the three documents explained
• How to build a pricing schedule: structure, coding and completion rules
• How to analyse a contractor's tender: the reading grid and the warning signs
• Tender stage risks: under-priced tenders, inflation and contracts with traps
• How to read a construction estimate and spot the hidden risks