Common mistakes in bill of quantities
A bill of quantities (sometimes referred to as 'BoQ' or 'BQ') is a document prepared by a cost consultant (often a quantity surveyor) that provides project-specific measured quantities of the items identified by the drawings and specifications in the tender documentation for construction works.
It is very important that bills of quantities are prepared according to a standard, widely recognised methodology. This helps avoid any ambiguities or misunderstandings and so helps avoid disputes arising through different interpretations of what has been priced.
However, there are some common mistakes that can be made in the bill of quantities. These include:
- Inaccurate measurement of quantities.
- The inclusion of irrelevant preliminary items (this can be due to using preliminary items from a previous project which, although it may be similar, contains differences in scope).
- Insufficient information given in the descriptions.
- Omissions and discrepancies between the BoQ and the drawings or specifications (perhaps due to out-of-date or inaccurate information being used).
- Omissions or double-counting of items (this can be due to more than one quantity surveyor working on the same bill).
- Omission of temporary works items.
There can also be errors made in the pricing, such as:
- Incorrect understanding of the work method.
- Past performance used to assume future productivity.
- Inexperience of the estimator.
- Ignoring the relationship between items of work.
- Changes that are made late in the process.
- Inaccurate assumptions regarding items in the BoQ.
- Arithmetic errors.
- Differences in currencies not considered.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
- Advantages of a bill of quantities.
- Approximate bill of quantities.
- Bill of quantities.
- Bill of quantities software.
- Common mistakes in construction tenders.
- Cost plans.
- Cost overruns.
- Elemental bill of quantities.
- Estimate.
- How to take off construction works.
- Measurement.
- Taking off.
- Types of bill of quantities.
Featured articles and news
From Chaucer to Fawlty Towers.
Electrotechnical excellence, now open for entries.
Net zero electricity grids BSRIA guide NZG 5/2024
Outlining the changes needed to transition to net zero.
CIOB Global Student Challenge 2024
Universitas Indonesia wins for second year running.
New project and cultural district described in detail.
The nature of EPCs, crticism and inaccuracies.
History, issues and redesign.
From waste recycling to energy performance the hierchy.
An introduction to WERCS and WEEE responsibilities
Dealing with 2 million tonnes of waste equipment a year.
Global BACS Market: analytics and optimisation
A BSRIA glance at building automation and control systems.
What it is and how to use it.
Types of insulating plaster by binder and insulant.
Investors in People: CIOB achieves gold
Reflecting a commitment to employees and members.
Scratching beneath the surface; a guide to selection.
ECA 2024 Apprentice of the Year Award
Entries open for submission until May 31.
UK gov apprenticeship funding from April 2024
Brief summary the policy paper updated in March.