Professional bill of quantities: what should be clear at handover?
A professional bill of quantities should explain not only how much work has been measured, but also the information behind the figures and what remains unresolved. Item descriptions and totals need a traceable basis in identified drawings, measurement workings and recorded assumptions. That gives the client, bidders and reviewer a common scope to read, rather than a set of numbers whose origin has to be guessed.
A professional bill of quantities needs a clear evidence chain
The description, unit and quantity connect design information with the contractor's offer. To review an item, a reader needs to identify the drawing, detail, specification or schedule supporting it. Where a calculation covers a particular floor or area, that boundary should also be visible to someone who did not prepare the workbook.
The BOQ does not replace design decisions. If documents conflict, record both references and a focused question for the relevant project role. A documented answer provides a basis for updating the calculation while retaining the previous version. See BOQ preparation for the wider workflow.
Identify the information set before measuring
Start with a document register: document name, discipline, revision and date. Mark what has been received, what is missing and which revision forms the calculation baseline. Permit drawings and working drawings may show different information; their purposes should be identified rather than silently combined.
- Drawings and details: architectural, structural, external works and the construction details within the agreed scope.
- Specifications and schedules: finishes, windows, metalwork and joinery, based on the information available.
- Reports and consultants' BOQs: the soil report, building services information and quantities supplied by consultants, where relevant.
- Purpose of the issue: a tender, subcontract work packages or another use agreed in the appointment.
New documents do not need to be commissioned solely to make an initial enquiry. Send the material already available and identify what is still expected. The presence of a model does not demonstrate that every detail, temporary work item or specification requirement is included in it.
What should be clear in each item?
| Component | What to check |
|---|---|
| Work description | The material, type and scope boundaries are identified, with a detail or specification reference where needed. |
| Unit and measurement basis | Area, volume, length or count is clear, together with the measurement rules agreed for the project. |
| Location and source | The relevant area, level, drawing number and revision can be found. |
| Trade boundaries | Supply, installation and interfaces with other work do not remain hidden assumptions. |
Chapter numbering helps readers navigate the document; it does not, by itself, establish a binding measurement method. Identify the basis that applies to the project documents and use it consistently. The measurement methods guide explains why a geometric quantity and a BOQ quantity may need different treatment.
A synthetic example: two quantities and a design question
The existing interactive example below is illustrative only. A fictional soil report defines a replacement area of 26 metres by 20 metres at a depth of one metre, giving 520 cubic metres. The fictional structural drawing marks only 13 metres by 20 metres at the same depth, giving 260 cubic metres. These are example inputs, not a recommendation for the replacement depth or extent on a real site.
| Item | Description | Unit | Quantity | Source |
|---|---|---|---|---|
| 01.030 | Excavation and removal of clay soil under the building, according to the soil report: the building footprint plus one metre on each side, one metre deep | m³ | 520.00 | Soil report |
| 01.040 | Imported fill, compacted in layers, in place of the replaced soil, according to the soil report | m³ | 520.00 | Soil report |
| — | Check: the same work according to the marking on the structural drawing, over half of the area | m³ | 260.00 | Structural drawing |
| — | Gap between the soil report and the marking on the drawing | m³ | 260.00 | Flag: question |
| 01.090 | Compaction tests of the compacted fill by an accredited laboratory | each | Missing | Missing |
The arithmetic difference is 260 cubic metres. The quantity surveyor records it with both references and raises a question with the geotechnical consultant and structural engineer. Neither the larger nor the smaller number should be selected automatically. The number of compaction tests also remains missing until the relevant instructions are available; it is not inferred from the volume alone. See the soil report and BOQ for more on the document interface.
Keep questions, assumptions and answers beside the quantities
A question register should let each issue be followed independently: a stable reference, affected item, source document, responsible project role, temporary assumption and review status. Record a documented answer with its date and reference, then identify the BOQ rows changed as a result.
Missing is different from zero: if the available material does not support a quantity, mark it as missing and explain the information required. Where a temporary assumption is used, state it explicitly and distinguish it from an input received from the design team.
The number of questions is not a quality score. A long list can still be difficult to act on, while a short list does not prove that a review is complete. Focused wording, clear references and a traceable resolution status are more useful to the reader.
Handover and revisions of a professional bill of quantities
At handover, identify the BOQ revision, its source documents and open questions. An organised calculation workbook lets the reviewer move from an item to the formula and supporting reference. Breakdown by building, floor or area depends on the agreed scope. See the quantity calculation workbook guide.
When a revised drawing arrives, retain the previous version and show what changed. Review omissions as well as additions. An amended quantity does not demonstrate approval to build or pay for the change, and measurement is not design approval. Keeping these decisions separate makes the record easier to understand later.
Preparing an enquiry
Yaakov Avital is a registered building technician and quantity surveyor for construction projects. He measures every detail like a contractor who needs to build it. An enquiry should identify the project type, stage and intended use, with the available documents attached. Scope, deliverables and terms are set out in a written quotation.
Pricing and cost estimating are additional services: verbal feedback on prices together with the client, with no commitment to a price. Preparing quantities does not automatically include payment application checking, tender administration or ongoing change management. Additional services are considered under a separate scope.
Frequently asked questions
What makes a professional bill of quantities?
Clear scope, consistent units, identifiable quantity sources and a record that distinguishes received information, assumptions and open questions. Presentation helps readers, but it cannot replace checkable measurement workings.
Does a model replace reading specifications?
No. Check what is in the model and what is held in other documents. A detail, schedule or specification requirement does not become a measured quantity simply because a model exists.
Who resolves conflicting drawings?
The authorised project roles decide. The quantity surveyor records the conflict and its effect on the calculation, then updates the BOQ against a documented answer.
Are prices included in quantity preparation?
Not automatically. Pricing and estimating are additional services with a separately defined scope, providing verbal feedback with the client and no commitment to a price.
* Created with AI for marketing, for illustration only. Not reviewed by Yaakov Avital and not professional advice. Every project must be checked on its own by a professional quantity surveyor and an engineer.