BOQ (Bill of Quantities)
A Bill of Quantities is the itemised, measured schedule of works — each item described, quantified and rated — that turns drawings into a priced contract and later governs interim billing, reconciliation and variations.
Why it matters on an MEPF project
The BOQ is where engineering meets money: tender comparison happens on it, running bills certify against it, and every quantity dispute returns to it. Its quality is therefore project-risk in document form — vague item descriptions invite rate games, quantities lifted from uncoordinated drawings guarantee variations, and missing items become extras at the worst negotiating moment.
Discipline shows in the details: items described with specification references (not "supply and install cable" but which cable, laid how, tested to what), measurable units, honest provisional sums ring-fenced, and a variation mechanism with named rates. Route-validated quantities — measured off coordinated drawings, not schematic intent — are what separate a BOQ from a wish list.
How it's specified in practice
| Parameter | Typical / working position | Governing reference |
|---|---|---|
| Item description | Work + spec reference + inclusions | measurement conventions |
| Quantity | Measured from coordinated drawings | take-off discipline |
| Rate | Unit rate carrying stated inclusions | tender |
| Control functions | Billing, reconciliation, variation pricing | contract administration |
Common mistakes
- Quantities from un-coordinated drawings — the 1,000 m cable that measures 1,470 on site.
- "Including all accessories" doing the specification's job.
- Provisional sums scattered instead of ring-fenced.
- No named mechanism for pricing new items.
Related on this site
One of 68 working definitions in the MEPF & solar engineering glossary. The buying side of the same decisions is in the buyer's guides; the numbers are in the calculators.
Frequently asked
Who pays when site quantities exceed the BOQ?
The contract's measurement/variation clauses decide — which is why they, and the quality of the original take-off, matter more than the rate page. Route-based validation before award is the cheap insurance.
What makes an MEPF BOQ hard to game?
Specification-referenced descriptions, coordinated-drawing quantities, explicit inclusions/exclusions per item, and named rates for likely variations. Our tendering insight covers the pattern in depth.
Standards referenced: measurement conventions (contract-stated)