The bill of quantities (sometimes referred to as ‘BoQ’) is a document prepared by the cost consultant (often a quantity surveyor) that provides project specific measured quantities of the items of work identified by the drawings and specifications in the tender documentation. The quantities may be measured in number, length, area, volume, weight or time. Preparing a bill of quantities requires that the design is complete and a specification has been prepared.
The bill of quantities is issued to tenderers for them to prepare a price for carrying out the works. The bill of quantities assists tenderers in the calculation of construction costs for their tender, and, as it means all tendering contractors will be pricing the same quantities (rather than taking-off quantities from the drawings and specifications themselves), it also provides a fair and accurate system for tendering.
The contractor tenders against the bill of quantities, stating their price for each item. This priced bill of quantities constitutes the tenderer’s offer. As the offer is built up of prescribed items, it is possible to compare both the overall price and individual items directly with other tenderers’ offers, allowing a detailed assessment of which aspects of a tender may offer good or poor value.