What is a BOQ in construction? A contractor's guide

What a BOQ contains

A BOQ breaks a project into measured work items. A typical line includes a reference, description, unit and quantity, with columns for the bidder's rate and amount. Bills or sections group related work so the reader can move from a summary into the detail.

The exact format varies. A consultant-issued tender BOQ may be detailed and tightly structured. A contractor's internal BOQ may be reorganized around work packages, suppliers or cost codes. The important part is that the team understands which document controls and how revisions will be tracked.

How contractors use a BOQ

At tender stage, the BOQ gives competing contractors a common list to price. Estimators build or select a rate for every line, then carry the amounts into bill and tender summaries.

After award, the priced BOQ can become a working cost document. Teams may use it to split procurement packages, compare committed cost with the estimate, support valuations and record changes. The contract determines its formal role, so project teams should not assume that every BOQ has the same contractual status.

Who prepares the BOQ?

A quantity surveyor or cost consultant often prepares the tender BOQ for the client or consultant team. Contractors may also create their own BOQ when tender information does not include one, when they need a trade package, or when the issued bill does not suit internal cost control.

Whoever prepares it needs a clear measurement basis and access to the current drawings and specifications. Good descriptions help bidders understand the scope. Good quantities can be traced back to a measurement source.

What to check before pricing

1. Confirm the BOQ revision and tender deadline.
2. Check that the drawing and specification revisions match the tender issue.
3. Scan for missing units, blank quantities, duplicated items and arithmetic errors.
4. Identify provisional, specialist or unclear scope that needs a query.
5. Record pricing assumptions and exclusions in a tender query log.
6. Assign each section to the person responsible for pricing and review.

A simple BOQ line example

Imagine a line measured in square metres. The description refers to a specific finish and installation requirement. The estimator should confirm the measured area, then build a rate using the current supplier quotation, labour output, accessories, waste allowance and the company's commercial method. The line amount is the accepted quantity multiplied by the tender rate.

This is why two BOQ lines with the same unit can require very different rates. The scope sits in the description and specification, not in the unit alone.

What comes after the BOQ?

If quantities have not been issued, start with a quantity takeoff. If the BOQ is ready, use a consistent BOQ pricing workflow and keep every quotation and assumption attached to the relevant line.