BESMM4 Work Sections and Coding System Explained (1.1 to 1.40)

Every line in a professionally prepared Nigerian bill of quantities carries a short reference — 1.5:6.2.1, 1.14:1.2.1, 1.11:34.1.2. Those references come from the NIQS BESMM4 coding system, and once you can read them you can tell at a glance what kind of work an item is and which measurement rule it was measured under. This guide lists all 40 BESMM4 building work sections, the civil engineering sections, and explains exactly how a BESMM4 code is built.

How BESMM4 is organised

BESMM4 (the Building and Engineering Standard Method of Measurement, 4th Edition, published by the Nigerian Institute of Quantity Surveyors) has three parts. The measurement rules themselves sit in Part 3: Tabulated Rules of Measurement, which is split into two sections:

• Section 1 — Building works, numbered as work sections 1.1 to 1.40.
• Section 2 — Civil and industrial engineering works, lettered 2A to 2AB.

If you are pricing a house, a block of flats or a commercial building, almost everything you need is in Section 1. (Older documents prepared under BESMM3 or UK methods used letter codes such as “D20” or “E10” for building trades — under BESMM4 building work is numbered 1.1 to 1.40.)

BESMM4 building work sections (Section 1)

Where common Nigerian building items fall

BESMM4 civil engineering work sections (Section 2)

Section 2 covers civil and industrial engineering work — roads, pipelines, sewers, bridges and the like: 2A General Items, 2B Ground Investigation, 2C Geotechnical and Other Specialist Processes, 2D Demolition and Site Clearance, 2E Earthworks, 2F In-situ Concrete, 2G Concrete Ancillaries, 2H Precast Concrete, 2J Pipework – Pipes, 2K Pipework – Fittings and Valves, 2L Pipework – Manholes and Pipework Ancillaries, 2M Pipework – Supports, Protection and Ancillaries to Laying Excavation, 2N Structural Metalwork, 2P Miscellaneous Metalwork, 2Q Timber, 2R Piles, 2S Piling Ancillaries, 2T Roads and Paving, 2U Railway Track Construction, 2V Tunnel, 2W Brickwork, Blockwork and Masonry, 2X Painting, 2Y Waterproofing, 2Z Miscellaneous Work, 2AA Sewer and Water Main Renovation and Ancillary Works, and 2AB Simple Building Works Incidental to Civil Engineering Works.

How a BESMM4 code is built

Each work section has a classification table. Down the left are the items commonly measured; across the top are columns (called divisions) of descriptive features. An item's code is the work section number, a colon, then the number chosen from each column, separated by dots:

work section : column 1 . column 2 . column 3 / column 4

Take 1.5:6.2.1:

Read together: “Excavation, commencing from stripped level; foundation excavation; not exceeding 2.00m deep”, measured in m³.

A few conventions to know:

• The fourth column follows a slash, e.g. 1.11:2.1.2/2 — horizontal concrete work, not exceeding 300mm thick, in structures, reinforced.
• An asterisk joins more than one entry from the same column, e.g. /1*2 means features 1 and 2 both apply.
• A zero means no entry was taken from that column, e.g. 1.11:13.1.0.
• Without dots: codes may also be written run together (1.5:621), but a slash is then needed wherever a number has two digits.

The description of each item takes one feature from each of the first three columns, in order — which is why BESMM4 descriptions read in that distinctive “kind; size; location” pattern.

Why the codes matter

• No ambiguity. The code tells the contractor exactly which measurement rules apply — what is included in the rate and what is measured separately.
• Comparing tenders. When every contractor prices items under the same codes, prices can be compared line by line.
• Software and cost data. Coded items can be sorted, analysed and reused for cost planning across projects.

For how the whole bill fits together — preliminaries, elemental bills, provisional sums and the Main Summary — read BESMM4 Bill of Quantities Format: How a NIQS BoQ Is Structured. For the measurement rules behind the most common items, see BESMM4 Measurement Rules: Concrete, Formwork, Blockwork and Reinforcement.

Frequently Asked Questions

How many work sections are in BESMM4?

Forty building work sections (1.1 to 1.40) in Section 1, plus the civil and industrial engineering sections 2A to 2AB in Section 2.

Which BESMM4 section covers blockwork?

Work section 1.14 Masonry, for building works. Blockwork incidental to civil engineering works falls under 2W.

Where do gutters and downpipes go in BESMM4?

Work section 1.33 Drainage Above Ground. Drainage below ground — septic tanks, soakaways, manholes and drain runs — is 1.34.

Is POP ceiling measured under finishings or suspended ceilings?

A suspended ceiling system (POP or PVC on a framework) belongs in 1.30 Suspended Ceilings. Plaster applied directly to a concrete soffit is a finishing under 1.28.

Do I need to know the codes to use a BoQ?

No — the descriptions say what the item is. The codes are mainly for the quantity surveyor and the contractor, to confirm which measurement rules apply.