How to read a tender Bill of Quantities

A Bill of Quantities (BoQ) is the priced skeleton of a construction tender. It lists, in a standard order, every measurable item of work with a quantity, and leaves a column for you to insert a rate. Priced up, the extended amounts add to your tender total. Learn to read one properly and you can see where the money is, where the risk is, and where a rival might be hiding a low number.

The columns

A typical BoQ line has: an item reference, a description of the work, a unit of measurement (m³, m², m, kg, No, sum), a quantity, a rate, and an amount (quantity × rate). Your job as the pricing contractor is to fill in the rate. The quantities are usually given (measured by the quantity surveyor from the drawings); your rate must cover materials, labour, plant, waste, and your mark-up for that item.

The sections

• Preliminaries: the P&G — site-wide costs, priced as items or as a lump sum.
• Measured work: the bulk of the bill, grouped by trade or element (earthworks, concrete, brickwork, roofing, finishes, services).
• Provisional sums: an allowance for work not yet fully designed, to be expended as instructed.
• Prime Cost (PC) sums: an allowance for materials or specialist work to be bought at a stated cost, with the contractor adding handling and profit.
• Dayworks: a schedule for valuing work done on a time-and-materials basis when no rate applies.
• Contingencies: a sum the client holds for the unforeseen — not yours to spend without instruction.

Measured vs provisional

Firm quantities are measured from a complete design and remeasured on completion; you carry the risk of your rate, not the quantity. Provisional quantities are estimates for work that isn't fully designed — they'll be remeasured and adjusted at your tendered rates. Knowing which is which tells you where the quantity risk sits and where it doesn't.

The traps

• Unbalanced pricing: loading rates onto early items (front-loading) to improve cash flow. Legal but scrutinised, and risky if quantities are remeasured down.
• Quantity errors: a bill quantity that looks wrong. Query it before tender close rather than pricing around it.
• Rate-only items: where you price a rate with no quantity — often for remeasurement. A high rate here can hurt if the actual quantity is large.
• Provisional and PC sums: don't mark these up as if they were your measured work; add only the handling and profit the contract allows.
• The 'sum' items in preliminaries: make sure your P&G is genuinely covered, not left thin to win the job.

Pricing it

Price each rate from a build-up: material cost plus waste, labour output, plant, and mark-up. Benchmark your rates against known figures for the trade so nothing is wildly out. A priced bill that's internally consistent — no random highs or lows — reads as competent to the QS assessing it, and protects you on remeasurement.

The BoQ Pricer imports a bill, suggests rates from South African benchmark data, and lets you adjust each line and export the priced bill — the practical companion to reading one.