Bill of quantities (BOQ)

A bill of quantities, abbreviated BOQ or BQ, is a document that lists the measured quantities of every item of work required to build a project, so that each tenderer prices the same scope at their own rates. It is prepared by a quantity surveyor working from the drawings and the specification. Every item carries a description, a unit and a quantity - linear meters of containment, square meters of ceiling tile, number of light fittings - and the contractor enters a rate against each one to arrive at a tender total.

What a BOQ contains and how it is measured

A UK bill is normally prepared to NRM 2, the RICS rules for detailed measurement of building works, published as part of the New Rules of Measurement suite. NRM 2 sets out how items are described, what each unit covers, and what is deemed included in a rate, which is what makes two contractors' prices comparable rather than merely similar. It also governs the treatment of preliminaries and provisional sums.

Beyond the measured work, a bill typically carries preliminaries, which price the cost of running the site rather than any single item of work, provisional sums for work that cannot be measured yet, and prime cost sums for materials or specialist work to be selected later. The measured sections are usually grouped by work section or by building element, depending on how the bill was structured.

BOQ, specification and scope of works

Three documents are involved in describing the same job, and they answer different questions. The specification says what standard and what product: the cable type, the luminaire code, the paint system, the workmanship standard. The scope of works says which tasks the contractor is responsible for, including exclusions. The bill of quantities adds the measured quantity to each item so it can be priced.

A schedule of rates is the fourth relative and the one most often confused with a bill. It carries rates without quantities, and is used where the amount of work is not known in advance - term maintenance, reactive repairs, dayworks. A bill fixes the quantity and asks for the rate; a schedule of rates fixes the rate and lets the quantity fall where it may.

On a commercial fit-out, the scope of works might say supply and install LED lighting to floors 2 and 3. The specification would name the luminaire code and the dimming protocol. The bill would list luminaire type A at 84 units, 50 by 50 containment trunking at 186 linear meters, and final circuit cabling at 1,240 linear meters. Every bidder prices those same three lines, which is what makes the returns comparable.

Smaller projects rarely have a bill at all. The contractor takes off quantities from the drawings itself, which is why several quotations for the same small job can differ by more than the rates alone would explain: the bidders have measured different amounts of work. Pricing from a bill in Zigaflow's quotes keeps each measured line, its rate and its supplier cost on the same document that later becomes the job.