- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 02 Oct 2020
Firm bill of quantities
A bill of quantities (BoQ) is a document prepared by a cost consultant 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. A bill of quantities is issued to tenderers for them to prepare a price for carrying out the works.
The more precisely the work in a bill of quantities can be measured and described (i.e. the ‘firmer’ it is) the more accurate tenderers’ prices should be, the easier it will be to control costs and the fewer variations will be necessary. The process of identifying elements of construction works that can be measured and priced is known as 'taking off'.
A firm bill of quantities can be prepared when the design is complete, a detailed specification has been prepared and quantities can be accurately calculated. If there were no changes to the project requirements following the preparation of a firm bill of quantities, then the tenderer’s priced bill of quantities would be the same as the final cost of the contract. In practice of course there are always changes.
Where it is not possible to prepare a firm bill of quantities at the time of tendering, an approximate bill of quantities (or notional bill of quantities) might be prepared. This might be necessary, for example, if the design is relatively complete, but exact quantities are not yet known. However, this will tend to result in more variations during construction and so less price certainty when the investment decision is made.
 Related articles on Designing Buildings Wiki
- Advantages of a bill of quantities.
- Approximate bill of quantities.
- Approximate bill of quantities vs approximate quantities cost plan.
- Approximate cost plan.
- Approximate quantities.
- Bill of quantities.
- Bill of quantities software.
- Common mistakes in bill of quantities.
- Cost plans.
- How to take off construction works.
- New Rules of Measurement.
- Priced bill of quantities.
- Quantity surveyor.
- Taking off.
- Types of bill of quantities.
Featured articles and news
CLC provides guidance related to product marks, post-Brexit.
Net zero goals incorporated into plans for a new European Bauhaus.
BREEAM offers its resilient approach to Building Back Better.
Country moves one step closer to creating independent body.
BSRIA examines factors driving the industry.
Ensuring designs are developed, validated and can be effectively implemented.
The Homebuyer Survey most suitable for newer homes or simple properties.
Health and safety practices for body and mind.
28 leading bodies set out their vision for the future.
Chancellor announces latest Winter Support packages.
Tapping technology to boost infrastructure and create jobs.
4 ways to ensure certificates are valid.
White elephant construction projects.
How Paul Williams bent over backwards to overcome racial barriers.