Editorial review: 19 September 2026. The examples below are illustrations, not current construction quotations.
A building estimate tells you a price. A useful bill of quantities helps you understand what that price is buying.
A bill of quantities, usually called a BOQ, is an itemised description of building work with measured quantities. When priced, it connects the work, units, quantities and rates to an amount. It should relate to your actual drawings and specifications. A document copied from another three-bedroom house is not automatically suitable for yours.
This guide is for homeowners comparing proposals, including Nigerians managing a project from abroad. It explains what to look for, not how to design a structure or replace a quantity surveyor.
A BOQ is not the same as a shopping list
A list saying “cement, blocks, sand and roofing” may help with procurement. It does not necessarily explain the complete work, labour, specifications, temporary facilities or costs outside those materials.
The Nigerian Institute of Quantity Surveyors’ material on standardising quantity-surveying documents describes BOQ components such as work sections, preliminaries and summary information. The arrangement can vary. What matters to you is that the document makes the scope understandable and the pricing traceable. Source: NIQS technical presentation.
Ask your quantity surveyor which measurement rules were used and what information was missing when the quantities were prepared. A professional-looking cover is not a substitute for those answers.
The six columns you should be able to follow
| Column | What it should tell you |
|---|---|
| Item reference | A stable number or code you can quote when asking a question. |
| Description | The work, relevant specification and what is included in that item. |
| Unit | How it is measured, for example square metres, cubic metres, number or an identified sum. |
| Quantity | The measured amount, linked to the project information. |
| Rate | The price per unit, with its inclusions understood. |
| Amount | For a measured item, quantity multiplied by rate. |
Do not compare two rates until you know they cover the same thing. A supply-only rate and a supply-and-install rate answer different questions.
Read one line together
Arithmetic illustration only, not a Nigerian market rate: suppose a hypothetical floor-finishing item measures 40 square metres and its invented supply-and-install rate is NGN 8,000 per square metre. The line amount is 40 x NGN 8,000 = NGN 320,000.
This example covers only that floor-finishing item in a hypothetical 120-square-metre bungalow. It is not a whole-house estimate, material recommendation or quotation. Land, structure, other finishes, professional fees, external works and contingency are outside the example.
The multiplication is the easy part. Before accepting the line, ask:
- Which room areas does the 40-square-metre measurement cover?
- Which product specification and installation work does the rate include?
- Are preparation, adhesives, trims, delivery and waste included elsewhere?
- What drawing revision supports the quantity?
- When was the rate obtained, and when does the quotation expire?
If the answers change, the amount may need to change too. Do not add a separate waste allowance automatically when the quantity or rate already includes it.
Check the costs outside the obvious work items
Build a separate inclusions checklist beside the BOQ. For every item below, record its location in the documents or write “not yet priced”. Do not enter zero just because you cannot find it.
- Site establishment, temporary services, security and access arrangements.
- Professional appointments and the scope of each professional’s work.
- Applicable approvals and the person responsible for confirming requirements and charges.
- External drainage, fencing, gates and other external works included in your brief.
- Water, electricity and other service connections or systems required by your design.
- Testing, commissioning, handover information and agreed close-out work.
- Tax treatment, risk allowances and assumptions about future price changes.
Some may already sit inside work rates or preliminaries. Your job is to locate them, not add every heading again. Have the quantity surveyor reconcile the building-work estimate with your whole-project budget.
Watch for allowances and incomplete design
An allowance is not necessarily a problem. Hiding the uncertainty is the problem.
If a sum has been inserted because a selection or scope is unresolved, ask what it covers, how it was set, who will resolve it and how the final adjustment will be recorded under your agreement. Ask the project professionals to explain any provisional or prime-cost sums in that specific document; do not assume every document uses the terms identically.
A line marked “electrical works: lump sum” is a reason to request the specification and breakdown. It is not evidence, on its own, that the contractor is dishonest.
What to send a quantity surveyor
Start with a short project brief: site location, intended use, target floor area, budget constraint, proposed timing and finish expectations. Then ask which drawings, specifications, site investigations and specialist inputs are required for the stage of estimate you need.
Use an issue list: document title, author, revision and date. When drawings change, ask whether the quantities and cost plan have been updated. Keeping an old BOQ beside new drawings makes comparison unreliable.
RICS’ cost-prediction standard emphasises the relationship between scope, information quality and professional judgement. It is a useful general principle, not a source of Nigerian prices or a substitute for local project advice. Source: RICS cost prediction.
Five questions to ask before relying on the total
- Which drawings and specifications does this version price?
- Which costs are excluded, and where will they sit in my overall budget?
- Which quantities or rates remain provisional?
- How will scope changes and price changes be recorded?
- Who will check the work and quantities when payment requests arrive?
Common questions
Can I use a sample BOQ for a three-bedroom bungalow?
Use a sample to understand the format and prepare questions. Do not use its quantities to order structural materials or promise a project budget. Houses with the same bedroom count can differ in area, layout, specification and site requirements.
Does a BOQ guarantee the final cost?
No. Changes, unresolved scope and the terms of the eventual contract affect how costs are managed. Ask the project professionals to explain the estimate’s limitations and the agreement’s adjustment provisions.
Should I start with a cost guide or a BOQ?
A guide can help you frame an early conversation. A project-specific cost plan and, where appropriate, a BOQ take that conversation closer to the work you actually intend to commission.
Start with our three-bedroom bungalow cost guide or five-bedroom duplex cost guide. Read their assumptions before applying any figures to your project.
Next in this series: compare contractors’ building quotes, then organise a weekly report when building from abroad.
Want to help shape a better budgeting tool? Join the Feasibility Studio waitlist. The tool is not presented here as a live estimator or professional BOQ service.
