Who produces the Bill of Quantities?

Usually the client's quantity surveyor or consultant, issued with the tender so that every bidder prices identical scope. On smaller jobs there may be no formal BOQ, and contractors take off quantities from the drawings themselves.

What is a provisional sum?

An allowance for work that is not yet fully defined. It is a placeholder to be re-measured or re-priced later, not a fixed price you have agreed to deliver for.

Do the rates include labour?

It depends on the preamble, which defines what rates are deemed to include. A composite supply-and-fix rate covers material, labour and associated work; a supply-only rate covers the material delivered and nothing else. Always check before pricing.

What are preliminaries?

The cost of running the site rather than doing the measured work — welfare, supervision, plant standing, temporary works and insurances. They are frequently under-priced because they are done last, and they do not scale with the measured quantities.

Home / Insights / What is a Bill of Quantities

What a Bill of Quantities is, and how to read one

Supreme Building Services · in Construction estimating

A Bill of Quantities is a line-by-line schedule of the measured work in a job — each item, the quantity, and the unit it is measured in. It exists so several contractors can price identical scope, which is why public and commercial tenders are usually issued with one. Read it as three things at once: what the work is, how much of it there is, and what each rate is expected to include.

What is in it

A typical line carries a reference, a description, a quantity and a unit. The unit tells you how the work is measured and therefore how it must be priced.

Unit	Means	Typical items
m	Linear metre	Drainage runs, kerbs, edgings
m²	Square metre	Paving, surfacing, membranes
m³	Cubic metre	Excavation, concrete, fill
tonne	Weight	Aggregates, muck-away
nr / each	Count	Manholes, gullies, chambers
item	A lump sum	Prelims, temporary works
sum	A stated amount	Provisional and prime cost sums

The lines that cost people money

Provisional sums

An allowance for work not yet fully defined. It is not a price you have agreed to deliver for — it is a placeholder that will be re-measured or re-priced later. Treating a provisional sum as fixed income is a classic way to be surprised.

Preliminaries

The cost of running the site rather than doing the work: welfare, plant standing, supervision, temporary works, insurances. Prelims are often priced last and thinnest, which is exactly backwards — on a long programme they are a large real cost and they do not scale with the measured work.

Rates with unstated inclusions

The single biggest trap. A line reading "110mm foul drain, 90m" might expect the rate to include excavation, bedding, pipe surround and backfill — or it might have those measured separately elsewhere. If you price supply-only against a supply-and-fix expectation, you have quoted a fraction of the real cost. Check the preamble, and see supply-only versus supply-and-fix rates.

How to price one quickly

Read the preamble first — it defines what rates are deemed to include, and it is the part everyone skips. Then price the lines that carry most of the value, because a handful of items usually account for the bulk of the total; chasing precision on ironmongery while guessing at the sub-base is effort in the wrong place.

Then get real quotes on those big lines before submitting anything. Our free BOQ pricer gives you a low, most-likely and high figure with the basis of each rate shown, which is enough to decide whether the job is worth a full submission — see the full estimating guide for how the bands work.

Got a bill you want priced?

Paste it into the free pricer, or send it over and we will price it properly and tell you what needs a supplier quote.