A Bill of Quantities, commonly shortened to BOQ or BQ, describes and quantifies construction work in a consistent format. Tenderers insert rates and prices against the measured items, helping the project team understand how each tender total has been built up.
What does a Bill of Quantities contain?
The precise structure depends on the project and procurement route. A building-work BOQ commonly contains preliminaries, measured work sections, provisional or contingency-related items where appropriate, and summaries. Each measured item normally includes a description, unit and quantity, with columns for the tenderer's rate and amount.
- Project and tender preliminaries
- Trade or elemental work sections
- Descriptions defining the measured work
- Measurement units such as number, metre, square metre or cubic metre
- Quantities derived from the tender information
- Rate and amount columns for pricing
- Section summaries and a tender total
How is a BOQ prepared?
The quantity surveyor first reviews the drawing register, specifications, schedules and tender instructions. The work is then measured using the stated measurement rules. Dimensions and quantities are checked before descriptions are written and organised into a pricing document.
Good measurement is not only a mathematical exercise. The preparer must understand construction sequence, materials, interfaces and the information a tenderer needs to price the work. Ambiguities, missing details and assumptions should be raised or clearly recorded.
BOQ, quantity takeoff and schedule of rates
These documents are related but not identical. A quantity takeoff records measured quantities and may be prepared for estimating, procurement or checking purposes. A BOQ is a coordinated tender or contract pricing document with descriptions, units, quantities and summaries. A schedule of rates may contain rates for defined work items without committing to final quantities.
The right deliverable depends on how the project will be priced and administered. Contractors may need a trade takeoff for an internal estimate, while an employer may need a coordinated BOQ so tenderers return prices on a common basis.
How a BOQ improves tender comparison
When tenderers price the same descriptions and quantities, the reviewer can compare trade totals, unit rates, exclusions and qualifications more efficiently. Unusual rates and unpriced items are easier to identify than in a single lump-sum quotation.
A BOQ does not make tenders automatically comparable. The reviewer should still check arithmetic, scope qualifications, proposed alternatives, provisional allowances and whether every tenderer used the issued document correctly. See the tender submission checklist for a broader final review.
Using the BOQ during construction
Where incorporated into the contract, BOQ items and rates may support progress valuations, variation assessment and cost reporting. The actual use depends on the contract. The document can provide a helpful pricing reference, but it should not be applied outside the contractual valuation rules.
Measured progress can be reconciled against BOQ quantities during progress claim assessment. Additions and omissions can also be recorded against the original work sections, improving visibility of the forecast final cost.
Information quality affects BOQ quality
A detailed BOQ prepared from incomplete design information can create a misleading impression of certainty. Before measurement begins, confirm the design stage and identify missing architectural, structural, mechanical and electrical information. Where assumptions are unavoidable, state them clearly and update the quantities when the design develops.
- Use a controlled drawing and document register
- Coordinate information between disciplines
- Record inclusions, exclusions and assumptions
- Identify provisional or undefined scope
- Check quantities independently before issue
- Issue revisions with a clear change record
Common BOQ problems
- Measurement based on superseded drawings
- Duplicated or omitted work between trades
- Descriptions that do not reflect the specification
- Inconsistent units or measurement rules
- Unclear treatment of contractor design portions
- Insufficient coordination of M&E and builder's work
- Late design changes not incorporated before tender
When should measurement start?
Measurement can begin once sufficient coordinated information is available for the intended level of accuracy. Starting early may help an estimator meet a tender deadline, but the deliverable should distinguish firm quantities from allowances. For a formal BOQ, a stable tender information set reduces remeasurement and pricing uncertainty.
What to provide to a quantity surveyor
Provide the latest drawings and schedules, specifications, scope boundaries, tender instructions, preferred work breakdown, measurement standard and required file format. The programme and tender deadline help determine priorities and whether staged measurement is appropriate.
Need a BOQ or quantity takeoff?
Share the available drawings, specifications, tender requirements and submission date. YuHuang can advise on the measurement deliverables and level of detail appropriate to your project.
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