Bill of Quantities (BOQ)

A Bill of Quantities (BOQ) is the itemized schedule prepared by the procuring entity that lists every measurable element of work or supply in a contract, with pre-defined quantities, against which competing bidders fill in their unit rates and extensions to produce a total contract price. It is the primary financial document in works contracts and enables fair, like-for-like comparison of bids.

What is a BOQ?

The BOQ is prepared by the procuring entity's engineer or quantity surveyor using the technical-specifications and drawings-and-plans as the basis for measurement. Each line item describes a discrete work item (excavation, concrete, reinforcing steel, brickwork, and so on), states its unit of measurement (cubic metres, tonnes, square metres), and gives the quantity. Bidders complete their unit rate for each item and calculate the line-item extension; the sum of all extensions gives the total bid price. Because all bidders price exactly the same quantities, the resulting prices are directly comparable.

The BOQ is also the mechanism for valuing variations and interim payments during contract execution. When the engineer orders a variation or certifies a monthly progress payment, the BOQ unit rates provide the agreed pricing basis. For this reason, a well-priced BOQ - with realistic unit rates across all items, not rates artificially loaded on early items - is both a competitive submission and a sound commercial foundation for contract administration.

Why the BOQ matters for bidders

Errors in BOQ pricing are very difficult to correct after bid submission. Most bidding documents prohibit bidders from amending unit rates after the submission deadline, though arithmetic errors in extensions may be corrected by recalculation. Contractors should therefore price every line item, even apparently minor ones, because omitted items cannot be claimed as extras later - the BOQ is the agreed schedule of rates for the whole scope. Extremely low unit rates on early work items followed by inflated rates on later items (front-loading) may be flagged as abnormally low and investigated under the unbalanced bids provisions of many development-bank contracts.

FAQ

What is the difference between a BOQ and a Schedule of Rates?

A BOQ has pre-defined quantities that the procuring entity has measured; bidders price unit rates against a fixed volume. A Schedule of Rates has no pre-defined quantities; payment is based on the actual quantities of work instructed, priced at the agreed rates. Both use the same unit-rate principle but allocate quantity risk differently.

Can I alter the quantities in the BOQ before submitting?

No. Bidders price the quantities as provided. If a bidder believes a quantity is wrong, they should raise a clarification request before the submission deadline. The procuring entity may issue a corrected BOQ as an addendum.

How are BOQ unit rates used during contract execution?

When the engineer certifies work done in an interim payment application, the quantity completed is multiplied by the BOQ unit rate to determine the payment due. For variation work not covered by existing BOQ items, the parties agree on a rate based on the nearest analogous BOQ item or on actual cost.