What is a bill of quantities? 

A bill of quantities (also known as a BOQ or BQ) is defined as “A detailed statement of work, prices, dimensions and other details, for the erection of a building contract”. 

Basically – A BOQ is a detailed itemised pricing document, usually prepared by a quantity surveyor or cost consultant to define the quality and quantity of work to be carried out by a contractor to complete a building project.

What is the purpose of a BOQ? 

A BOQ is useful for a number of reasons, especially in the construction industry. This includes: 

• The tendering process is standardised and therefore easy for contractors to use
• Provides a clear and precise method to value a construction project
• Enables consultants to analyse prices of a variety of items and overall costs
• Assists quantity surveyors when verifying individual contractors – ensuring they have submitted genuine tenders 

A BOQ is an important document which facilitates all contractors to price on the same information as well as providing a detailed scope of the work to be completed.

How is a BOQ prepared? 

The bill of quantities should be prepared by a quantity surveyor who will examine the drawings for a project, using this to prepare a list of work items which will be described in detail and allocated a cost estimate. 

The BOQ will usually be prepared in the pre-construction phase of a project. The process is as follows:

1. Receive the drawings and specifications created by the design team or architect 
2. Ensure understanding of the type of contract to be used
3. Take the quantities from the drawings
4. Draw up BOQ using this information 

What types of BOQ are there? 

Firm Bill of Quantities: Where work is measured and described precisely which enables those pricing it to price with precision.

Approximate Bill of Quantities: This involves the measurement and description of quantities that may be provisional. This may be used when a project has reached the tendering stage, however, the amount of information available about the design is limited and therefore not enough to create a precise BOQ.

When is a BOQ needed? 

For tender – When looking for a contractor it is important to get multiple quotes to compare. The BOQ makes it easier to get quotes for the same quantities and items. 

To reduce costs – A BOQ is useful for reducing costs as you can easily identify the most costly items and look for alternatives. This is especially useful when carrying out value engineering activities. 

For the contract – The BOQ will form a part of the contract fixing both the design and the cost. 

What is the process of creating a BOQ?

• Describe the work

This simply means the work needs to be described in detail and in simple words so your contractor can easily understand the tasks at hand. This article shows a detailed description of codes you can use to describe different tasks such as ‘A – Preliminaries and general conditions’ or ‘H – Cladding and covering’. 

• Work out the quantities 

This step requires the amount of work to be carried out to be given in units such as m3, m2, rm and foot. The more specific the quantities the better. 

• Describe the rates 

This step requires the rates of items of work in units. These can be measured in metres, square metres, cubic metres and number of.

Common mistakes made when creating a BOQ – It would be useful to check over your BOQ once it has been created to ensure that none of the following mistakes are made.

• Measurements of quantities of work are incorrect 
• Inclusion of unnecessary activities
• Some items are forgotten
• Discrepancies in the items of work and the drawings
• Miscounting of items of work
• For big projects – Lack of consideration for different currencies 
• Counting errors

For a good example of how to calculate elements of the BOQ – this article from Daily Civil is helpful.

What are the advantages of using a BOQ? 

• Save time – A BOQ will save you time during the tendering stage of a project. As previously stated, you can gain multiple quotes from different contractors knowing that they all have the correct tender information. This also saves the contractors having to do their own BOQ, ensuring your getting an accurate quote. 
• Improved project management – The BOQ will assist your project manager as the data for different aspects of the project are clearly noted down. As well as this the project manager can use this information for monthly progress reports and life cycle costs.
• Assists with future estimating and cost planning – This document can be kept and referred to for future projects as well as keeping track of how much costs are going up or down for certain materials. 
• Simplified tender analysis – The BOQ makes it much easier to analyse the costs of a project, helping with value engineering. 
• Transparency – As all items and quantities are specified there is greater transparency of the project between all stakeholders.
• Provides extensive and clear documentation of the work to be carried out 
• Aids with asset management – The BOQ contains all the data needed to analyse completed projects, life cycle cost, maintenance schedule, insurance and possible replacement costs.
• Assists with budget management and cost controls – This shouldn’t be overlooked during the planning and construction phases of a project as it can be easily controlled.