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.
Approximate bills of quantities can also be used during the design process as a tool for controlling design development.
[edit] 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.
- Working up construction works.
Featured articles and news
Designing sustainability and performance into buildings
Specifying and selecting sustainable resilient timber products.
Modifying wood to improve resistance to decay and movement.
A last minute, long look for built environment professionals.
The architecture of creative reuse. Book review.
Installing solar panels on listed structures.
Sustainable development global goals, history in progress?
"Unless we act now, the 2030 Agenda will become an epitaph for a world that might have been."
Mike Kagioglou FCIOB named CIOB President
'Sustainable Development Goals must be focus for construction'
BSRIA training; a look at what's on offer
From energy management to compliance training.
TESP video warns to beware of rogue trainers.
Highlighting the slippery tactics of non-approved providers.
New Building Safety Wiki launched
Boosting awareness and understanding of the new fire safety regime.
New playbook on AI in construction published by CIOB
How to get to grips with, and the best from AI.
Digital Construction Report NBS
BIM, cloud, off-site, immersive tech, AI, twins and sustainability.
ECA learning zone and industry focus video series
From updates and amendments to circular economy, emergency lighting and much more.
The Building People Communities Network
Celebrating and amplifying voices of the under-represented, this refugee week and pride month.
Pride of Place: queer heritage
Acknowledging and taking pride in LGBTQ histories.