How to price a bill of quantities from first principles

Start with the rules of measurement

A bill of quantities is only as good as the rules it was measured to. Before you price a single item, read the preambles and find which method of measurement the contract names. Building work under JBCC is commonly measured to the ASAQS standard system for building work. Civil work under the GCC is commonly measured to the SANS civil engineering standards. NEC and FIDIC contracts state the method in the contract data or the specification.

The measurement rules tell you what each item includes. If formwork, waste or working space is deemed included in the concrete rate, you must price it there. If it is measured separately, pricing it twice inflates your tender.

Check the quantities yourself

You are pricing the bill, but you are building from the drawings. Take off the big-value items yourself: concrete, reinforcement, brickwork, earthworks and roofing. Where your quantity differs materially from the bill, raise a written clarification before the cut-off in the tender data.

In a re-measurable contract you are paid for what is actually built, so a short bill quantity is less dangerous. In a lump-sum contract the bill quantity may carry more risk. Your own take-off also tells you how much material to order and how long the work will take.

Build the rate from first principles

Every unit rate has four parts:

1. Materials, at delivered prices from written quotations, with a waste allowance.
2. Labour, as gang cost per day divided by realistic output per day.
3. Plant and small tools, hired or owned, spread over the output.
4. Waste and breakage, applied to materials, usually as a percentage.

Labour cost must include on-costs, not just the daily wage. That means UIF, COIDA, leave, bonus, bargaining council levies where they apply, transport and protective clothing. These commonly add 35 to 50 per cent to the basic wage.

Worked example: one-brick wall, per m²

Assume a 220 mm wall in NFP bricks in class II mortar, priced at assumed 2026 prices. Your own quotations will differ.

• Bricks: 110 bricks per m², plus 5 per cent waste, gives 115.5 bricks at R2.80 delivered: R323.40.
• Mortar: 0.06 m³ per m², plus 10 per cent waste, gives 0.066 m³. One m³ of mortar needs about 7 bags of cement at R110 (R770) and 1.25 m³ of sand at R450 (R562.50), so R1,332.50 per m³. That is R87.95.
• Labour: one bricklayer at R450 a day and two labourers at R300 each is R1,050, plus 40 per cent on-costs, giving R1,470 a day. At an output of 9 m² a day, that is R163.33.
• Plant and tools: mixer, scaffolding and small tools at R15.00.

Net cost: R323.40 + R87.95 + R163.33 + R15.00 = R589.68 per m².

Add 8 per cent head-office overheads (R636.85), then 7 per cent profit, giving R681.43. Round to R681 per m². Whether you add overheads and profit into each rate or as a separate sum depends on the bill's layout and your firm's practice.

Price the preliminaries and general items

Preliminaries cover the cost of running the site rather than building any one item. Split them into three kinds:

• Fixed: establishment, site offices, hoarding and removal at the end.
• Time-related: site agent, foreman, security, site office running costs and plant on standing time, priced per week or month.
• Value-related: insurances, guarantees and some levies, which move with the contract value.

Pricing these properly matters later. If the works are delayed, time-related preliminaries are often the basis for valuing the extra time.

Check against benchmarks

Once the bill is priced, compare key rates with your own recent tenders, completed jobs and published cost guides. A brickwork rate far below your last three jobs usually means a missed cost, not a clever saving. Check the totals too: preliminaries as a share of the contract sum, and the cost per m² of floor area, against similar buildings.

A tender timeline with real dates

Say tenders are issued on Monday 16 February 2026 and close at 11:00 on Thursday 12 March 2026. Counting working days and assuming no public holidays fall in this period, you have 19 working days including the issue date.

• By Wednesday 18 February: send material and subcontract enquiries.
• Tuesday 24 February: attend the compulsory site inspection.
• By Wednesday 4 March: chase outstanding quotations.
• Monday 9 to Wednesday 11 March: adjudicate, add markup and get sign-off.
• Thursday 12 March: deliver before 11:00, allowing for traffic and security at the tender box.

A tender that arrives after the closing time is normally not considered at all. A mispriced rate, once accepted, generally becomes the rate you are paid at, including for variations valued from the bill.

Common mistakes

• Using the basic wage without on-costs.
• Taking outputs from a good day rather than an average week.
• Forgetting waste, cutting or breakage.
• Pricing items already deemed included elsewhere by the measurement rules.
• Leaving rates blank or writing "included" without knowing where the cost sits.
• Front-loading rates so heavily that later items are priced at a loss.
• Ignoring price escalation on a long contract without a price-adjustment clause.

Your contract may differ

This guide describes general practice across JBCC, NEC, FIDIC and GCC work. The signed contract's own amendments govern over the standard conditions: Z clauses, particular conditions, contract data, and the bill's own preambles and stated method of measurement. This guide is not legal advice.

What Sakhani does

Sakhani does not price bills. Once the contract is signed, it reads the contract, counts the days from each event, reminds the people responsible and drafts the notice for a person to send. That helps your bill rates and preliminaries get used to value variations and delay. See how it works.