A bill of quantities (BOQ) is a document that lists every item of work in a construction project, with its quantity, unit, rate and total cost. It turns your drawings into a priced list, so you can see exactly what you are paying for, compare contractors fairly and value work as it is completed. If a quote is just a single total, you cannot check it; a BOQ lets you check every line.
Who prepares a BOQ?
A quantity surveyor usually prepares the BOQ from the architectural and structural drawings. Contractors then fill in their rates. In design-and-build projects, the contractor prepares and prices it. In Tanzania, quantity surveyors are registered with the Architects and Quantity Surveyors Registration Board.
How is a BOQ structured?
Most BOQs are divided into sections that follow the order of construction:
- Preliminaries: site setup, insurance, supervision, temporary works.
- Substructure: excavation, foundations, ground slab.
- Superstructure: walls, columns, beams, slabs, lintels.
- Roofing: trusses, covering, gutters.
- Doors and windows.
- Finishes: plaster, ceilings, floor and wall tiles, paint.
- Services: plumbing, drainage, electrical.
- External works: boundary wall, paving, drainage.
- Provisional sums and contingency.
How do you read a BOQ line?
| Item | Description | Unit | Quantity | Rate | Amount |
|---|---|---|---|---|---|
| 2.1 | Excavate foundation trench, average depth 1.0 m | m³ | 45 | rate | quantity x rate |
| 3.4 | 225 mm cement block walling in cement mortar | m² | 180 | rate | quantity x rate |
| 6.2 | Supply and fix ceramic floor tiles | m² | 110 | rate | quantity x rate |
Each line tells you what is being done, how much of it, and at what price per unit. The amount is simply the quantity multiplied by the rate.
What are provisional sums and prime cost sums?
- Provisional sums are allowances for work that cannot be measured yet, for example unknown rock in excavation.
- Prime cost (PC) sums are allowances for items you will choose later, such as tiles or sanitary fittings.
Both are estimates and will be adjusted to the actual cost. A quote with many provisional sums is less certain than it looks.
How do you compare quotes using a BOQ?
- Give all contractors the same BOQ and drawings.
- Compare the totals per section, not only the grand total.
- Look for very low rates, which may mean poor quality or later claims.
- Check that nothing is excluded, such as external works or preliminaries.
- Ask questions about any rate that is far from the others.
Why is a BOQ worth paying for?
A BOQ costs a little at the start but saves much more. It reveals missing items before work begins, makes contractors' prices comparable, controls variations and makes progress payments fair. Read our guide to avoiding cost overruns.
Frequently asked questions
What is the purpose of a bill of quantities?
To list and price every item of work so that you know the full cost, can compare contractors and can value completed work.
Is a BOQ the same as an estimate?
An estimate is a rough cost. A BOQ is a detailed, measured list based on drawings, which is much more accurate.
Can I get a BOQ without drawings?
Not a reliable one. Quantities are measured from drawings, so drawings come first.
Does the BOQ include materials and labour?
Usually yes. Each rate normally covers materials, labour, equipment and the contractor's overheads, unless the BOQ states otherwise.
Get a clear, itemised price
Vika Construction prices every project in detail so you can see exactly what you pay for. Read about project management or contact us.
