If you have ever been handed a Bill of Quantities by a Nigerian quantity surveyor, you will have noticed it follows a familiar pattern: a summary page, preliminaries, bills grouped by part of the building, provisional sums, and item references like 1.11:2.1.2/2 beside each line. That pattern comes from BESMM4 — the Building and Engineering Standard Method of Measurement, 4th Edition, published by the Nigerian Institute of Quantity Surveyors (NIQS). This guide explains what BESMM4 is, how a BESMM4 bill of quantities is structured from front to back, and what changes compared with the simple materials list most homeowners are used to.
What is BESMM4?
BESMM4 is Nigeria's standard rulebook for how building and engineering work is measured and described in a bill of quantities. It does not set prices. Instead, it makes sure every QS measures the same work the same way — the same units, the same item descriptions, the same things included or excluded — so that contractors pricing a tender are all pricing exactly the same scope.
It is the latest in a line of Nigerian standards:
| Edition | Year | What changed |
|---|---|---|
| SMMBWS (Standard Method of Measurement of Building Works and Services) | 1988, revised 1996 | The first Nigerian standard method |
| BESMM2 | 2002 | Introduced the coding system for item references |
| BESMM3 | 2008 | Corrections; coding designed for use with CAD and QS software |
| BESMM4 | 2015 (in use from January 2016) | Reviewed and reorganised; added risks, redefined provisional and PC sums, removed items rarely carried out on site |
The book is in three parts: Part 1 sets out the general rules, Part 2 covers how a bill of quantities is prepared and composed, and Part 3 holds the tabulated rules of measurement — Section 1 for building works (work sections 1.1 to 1.40) and Section 2 for civil and industrial engineering works (2A to 2AB).
The parts of a BESMM4 bill of quantities
BESMM4 lists the sections a bill of quantities usually contains. In order:
- Form of Tender — where the contractor writes the tender price. Once accepted, it becomes the contract sum.
- Main Summary — the totals of every bill, carried to one page (see below).
- Preliminaries — in two parts: information and requirements (project particulars, the drawings, site constraints, contract conditions, the employer's requirements) and a pricing schedule where the contractor prices site set-up, management, temporary works, insurances and the like.
- Measured work — the bills of measured items, including any contractor-designed work.
- Risks — a list of specific risks the employer wants the contractor to carry, each priced by the contractor as a fixed lump sum.
- Provisional sums — money set aside for work that cannot yet be measured, marked as either defined or undefined.
- Dayworks (provisional) — rates for any work that may be paid by time spent.
- Annexes — supporting information such as performance specifications or quotations.
The Main Summary, in BESMM4 order
The Main Summary is where most clients look first. BESMM4 sets out its order like this:
| Summary line | What it holds |
|---|---|
| Preliminaries | The main contractor's site costs not tied to one element |
| Measured work | Grouped as Facilitating works, Substructure, Superstructure, Internal finishes, Fittings & equipment, Services, Complete buildings, Works to existing buildings, External works |
| Risks | Lump sums for the risks transferred to the contractor |
| Provisional sums | Defined, undefined, and work by statutory undertakers |
| Overheads and profit | The contractor's head-office costs and profit |
| Credits, fixed-price and director's adjustments | Any refunds for materials arising and pricing adjustments |
| Dayworks (provisional) | Allowance for time-charged work |
| Total price | Carried to the Form of Tender (VAT shown separately) |
Elemental bills: how the measured work is arranged
Most Nigerian building BoQs arrange the measured work elementally — one bill for each part of the building — and inside each bill the items are measured using the BESMM4 rules and grouped under their work section. A typical house BoQ runs:
Substructure → Frame → Upper Floors → Roof → Stairs → External Walls → Internal Walls → Windows → Doors → Wall Finishes → Floor Finishes → Ceiling Finishes → Fittings → Sanitary & Water Installations → Electrical Installations → External Works & Drainage
Each bill ends with a line “carried to summary”. So inside the Substructure bill you might see a heading 1.5: Excavating and Filling followed by excavation and backfilling items, then 1.11: In-situ Concrete Works with the footing and ground slab, then 1.14: Masonry for the foundation blockwork. (The alternative is to arrange the whole bill by work section instead of by element — BESMM4 allows either, and the summary then lists work sections.)
What makes an item “BESMM4”
Three things separate a BESMM4 item from a line in a materials list:
- It measures finished work, not materials. A materials list says “1,200 nos 9-inch blocks, 25 bags cement, 5 tons sand, labour”. A BESMM4 bill says “225mm hollow sandcrete blockwork in cement-sand mortar (1:6); external walls — 120 m²” with one built-up rate covering blocks, mortar and labour.
- It is described in a fixed order. Each description takes one feature from each column of the classification table — for example, kind of work, thickness, then where it is — so every QS writes the same item the same way.
- It carries a code. The reference tells you exactly which rule it was measured under. We explain the coding system in BESMM4 Work Sections and Coding System Explained.
Materials list vs BESMM4 bill: a quick example
| Simple materials-style BoQ | BESMM4 elemental BoQ |
|---|---|
| Concrete for structural columns (1:2:4) — m³ “including formwork” | Three items: concrete in columns (m³), formwork to sides of columns (m²), reinforcement by bar size (tonnes) |
| Iron rods 12mm — 45 lengths | High yield steel bar reinforcement; 12mm; straight and bent — 0.24 t |
| Blocks + cement + sand + block-laying labour (four lines) | One item of blockwork in m², with the materials and labour in its rate |
| Contingency and contractor's margin at the bottom | Risk, provisional sums, preliminaries and overheads & profit in their own places in the Main Summary |
For how individual trades are measured — concrete, formwork, blockwork and reinforcement — see BESMM4 Measurement Rules: Concrete, Formwork, Blockwork and Reinforcement.
Who needs a BESMM4 BoQ?
- Tenders and public projects, where contractors must price a common, standard document.
- Building loans and mortgages, where lenders ask for a properly structured, priced BoQ.
- Interim valuations — paying a contractor for work done is far easier when the bill measures finished work in m², m³ and tonnes.
- Contractors and QS firms who want a standard draft to refine rather than starting from a blank sheet.
For a formal tender or contract, the BoQ should be prepared or signed off by a registered quantity surveyor. See what quantity surveyors charge in Nigeria.
Frequently Asked Questions
Is BESMM4 compulsory in Nigeria?
BESMM4 is the standard method published by NIQS and is what Nigerian quantity surveyors work to, so tender documents and professionally prepared BoQs are expected to follow it. A homeowner's own budget estimate does not have to — but a structured BoQ is much easier for contractors and lenders to work with.
Does BESMM4 give material prices?
No. BESMM4 only governs how work is measured and described. Rates come from the market — the contractor's own pricing, or a price database like ours for indicative figures.
What is the difference between a defined and an undefined provisional sum?
A defined provisional sum is for work not fully designed but whose nature, extent and fixing are known well enough to describe; the contractor can allow for it in programming. An undefined provisional sum is for work where even that information is not available.
What does “Risks” mean in a BESMM4 BoQ?
It is a list of specific residual risks — for example, disposal of contaminated ground — that the employer wants the contractor to take on. The contractor prices each one as a fixed lump sum.
Can software produce a BESMM4 BoQ?
Software can produce a BoQ arranged in the BESMM4 elemental format with work-section codes and measured quantities, which saves hours of setting out. It should still be checked by a registered QS before formal use, because measurement depends on the actual drawings and specification.
Get Your BoQ in the BESMM4 Elemental Format
Our free Building Cost Estimator now downloads your BoQ two ways: the simple trade-by-trade version, or arranged in the NIQS BESMM4 elemental format — elemental bills, work-section codes, measured quantities and a Main Summary. Same estimate, same total. See what's in it.
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