What does BOQ mean? Its Components, Preparation Steps, and the Difference Between It and Quantity Takeoff

Many people search for the meaning of BOQ when entering construction and contracting projects. The Bill of Quantities (BOQ) is a pivotal document in the lifecycle of any engineering project, but understanding its true role is closely tied to the type of contract and the project phase.

In this educational guide, we clarify the exact meaning of a BOQ, the difference between it, takeoff, and pricing, and the correct steps for its preparation.

What does BOQ (Bill of Quantities) mean?

Simply put, the Bill of Quantities (BOQ) is a document that translates engineering drawings and specifications into a list of organized items. Each item usually consists of:

1. Item Number: The sequence of the item in the project.
2. Description: A brief explanation of the required work and materials used (linked to technical specifications).
3. Unit: The method of measuring the item (linear meter, square meter, cubic meter, number, lump sum).
4. Quantity: The number resulting from the "quantity takeoff" process.
5. Unit Rate: Left blank by the engineering office for the contractor to fill in their price.
6. Total: The product of multiplying the quantity by the unit rate.

For practical illustration, you can download an educational BOQ sample (CSV) to see the final shape of the table and how items are sequenced (quantities in the sample are hypothetical for explanation purposes).

The Difference Between Quantity Takeoff, BOQ, and Pricing

To simplify the concepts:

• Quantity Takeoff: Is the "calculating process" and extracting measurements and dimensions from drawings (architectural, structural, electromechanical).
• The BOQ: Is the "document or table" where the results of the takeoff process are placed in an organized manner according to project divisions.
• Pricing/Estimation: Is adding the financial cost to each item based on market prices and labor, which is mostly done by the contractor.

Is the BOQ Always a Binding Contractual Document?

A common mistake is considering the bill of quantities as a final and binding contractual document in all cases. In reality, the role of the BOQ is determined by the "contract type":

• In Remeasurement Contracts: Quantities in the bid are provisional. During execution, the contractor is paid based on the actual takeoff executed on the ground.
• In Lump Sum Contracts: The contractor is committed to executing the scope of work described in the drawings for a fixed total amount. In this case, the BOQ might be included as a schedule to price interim payments or variation orders, but the final reference is the drawings and specifications, not a shortage or excess of quantities in the table (unless the contract states otherwise).

(Disclaimer: The mechanisms mentioned as general examples are based on standard contract models like FIDIC Red Book, Second Edition 2017, Clause 12, and the actual mechanism always depends on the contract conditions signed between the parties. These examples are not considered a general rule applicable to all projects).

Steps for Preparing a Bill of Quantities (BOQ)

1. Studying Drawings and Specifications

Preparing the bill relies on the available drawings. In the Tendering phase, design drawings are used. For accurate takeoff before execution, it is preferable to use Shop Drawings.

2. Takeoff Process and Applying Measurement Rules

The engineer calculates lengths, areas, and volumes. To ensure consistency of measurements across projects, it is recommended to rely on standard measurement rules such as the recent edition of NRM 2: Detailed measurement for building works (2nd Edition, October 2021) issued by the RICS. (Note: NRM 2 is an engineering standard to unify the language of measurement and avoid overlap, but it is not a legally binding document unless your specific project documents stipulate adherence to it).

3. Drafting and Describing Items

The description must be clear, detailed enough, and linked to the projects technical specifications reference to avoid any misunderstanding during execution.

4. Quality Checks

This is a step to audit the conformity between the bills and the drawings, ensuring items are not duplicated (e.g., calculating excavation work twice) or omitting necessary works that are not clearly drawn but are required from an engineering standpoint.