SMM7/NRM2: The Key to Accurate Tendering

Making precise Bills of Quantities (BOQs) is an essential duty in the construction industry. Two well-known industry standards that are essential to this process are the New Rules of Measurement (NRM2) and the Standard Method of Measurement (SMM7).The primary reason for establishing official regulations was to address serious problems brought on by an earlier lack of consistency in measuring procedures.

The Need for Uniform measurement

The primary goal of publishing the first edition of the SMM in 1922 was to develop a uniform measurement method. Quantity surveyors designed SMM to remove the uncertainty that has prevented appropriate tendering by standardizing the measuring of building projects.
By guaranteeing that all bids utilize the same terminology and scale when vying for a contract, these standards serve as a “universal language” for assessing construction work.
Standardizing the BOQ and following SMM7/NRM2 while producing documentation enables clear, competitive pricing throughout the project lifecycle.
Crucially, a BOQ prepared to these standards ensures that all contractors tendering for a contract are able to price on exactly the same information.

Standardization: The Basis for Fair Tendering

The standardization provided by SMM7/NRM2 guidelines creates a level playing field in the tendering process. By removing doubt regarding the meaning and intent of billed items, this approach limits the financial risk element borne by the contractor, thereby encouraging them to submit more competitive and realistic tenders.

SMM7: Foundations of Measurement

A Quantity Surveyor (QS) must follow a comprehensive set of General Measurement Principles to ensure that a BOQ is accurate, consistent, and compliant with standards like SMM7.

The foundation and methods of measurement:

1. Net as fixed: Measurements must be taken in relation to the work net as fixed in position, unless a particular regulation permits an exception.
2. Dimension order: Entering dimensions in the right order is crucial. i) length; ii) breadth or width; and iii) depth or height.
3. Rounding Rules:
   • Dimensions should be rounded to the nearest 10 mm. 
   • Quantities in LM, m², or m³ should be rounded to the nearest whole unit. 
   • Quantities in tonnes should be rounded to the nearest two places of decimals.
4. Rules for Void Deductions:
   The deduction rule for voids or openings is specific to the trade and the void’s location. The rules for SMM7 voids and openings deductions are as follows:
   1. Volume-Based Deductions (Cubic Measurement)
      • In situ Concrete (E10) and Diaphragm Walling (D40):
        Concrete is generally measured net, but no deduction is made for voids ≤ 0.05 m³. This exclusion does not apply to voids in trough and coffered slabs.
   2. Area-Based Deductions (Superficial Measurement): Deduction limits depend on the specific material or work section.
      Small Voids (≤ 0.10 m²):
      • No deduction for voids ≤ 0.10 m² in Brick/Block Walling (F10/F11) and Natural Stone Rubble Walling (F20/F21/F22).
      • There is no deduction for flues, lined flues, and flue blocks when the combined amount of void and displaced work is less than 0.25 m².
      • Intermediate Voids (≤ 0.50 m²): No deduction for voids ≤ 0.50 m².
        Larger Voids (≤ 1.00 m²):
      • No deduction for voids ≤ 1.00 m² in patent glazing/structural glass assemblies (H10/H12/H13), curtain walling (H11), fiber cement profiled sheet cladding/covering (H30–H41)
        , and flexible sheet tanking/damp-proof membranes (J40–J43).
   3. Linear-Based Deductions: For partitions and linings measured linearly, no deductions are made for voids.

Content and Structure of a Standard BOQ

SMM, particularly SMM7, dictates the precise structure, content, and format of the BOQ, ensuring it functions as a contractual document.

Description Requirements

Billed descriptions must be reasonably comprehensive and sufficient to enable the estimator to fully understand what is required and provide a realistic price.

• Required Content: Descriptions must cover all matters detailed in SMM7, including the quality and quantity of works.
• It may be necessary to use Extra Measured Units (EMUs) to give further context. For example, when the concrete volume is measured in m³, the area (m²) of a retaining wall should be noted.
• Standardized Format: SMM7 is organized according to the Common Arrangement of Work Sections (CAWS), and in accordance with a tiered format (Levels 1–4), descriptions are usually organized using classification tables.
• Cross-Referencing: Descriptions can be significantly shortened by cross-referencing clauses in a project specification.

Deemed to be Included Items

A compliant description does not require specific mention of items “deemed to be included” in the billed price, but the estimator must include their cost in the rate. Typical inclusions are:

• Labor, materials, goods, and plant, including all associated costs.
• Assembly, fitting, fixing, waste of materials, square cutting, establishment charges, overheads, and profit.

Specific examples

• include all rough and fair cutting in brickwork/blockwork
• underlay and battens for roof coverings.
• For excavating drain trenches, the included work covers supporting the earth, leveling the bottom of the trench, trimming, filling with regular materials, and carting away.

The Standard BOQ Structure

The traditional BOQ structure is based on the Common Arrangement of Work Sections (CAWS), which ensures consistency between the specification and the bills.

1. Preliminaries Bill (Section A): This bill covers contractual, financial, and general costs that relate to the project as a whole. It includes general particulars, drawings, site details, and the Employer’s Requirements (A30-37). Pricing separates items into fixed and time-related charges, and it includes provisional and prime cost sums for provisional work and work by nominated subcontractors.
2. Preambles: these are essential clauses inserted at the head of each work section. They convey detailed specification information on materials and workmanship. Their function is to reduce the length of billed item descriptions. Critically, since the BOQ is always a contract document, the preamble specification details gain contractual status even if the specification document itself does not.
3. Measured Work Sections: This is the bulk of the BOQ, divided into main work sections (e.g., D20 for Excavating and Filling). Items are grouped in sequence: cubic, square, linear, and enumerated.

How SMM7 Minimises Construction Risks

The SMM7 is an essential tool for risk reduction because it creates a consistent framework that benefits both the client and the contractor while avoiding conflicts through transparency and contractual clarity.

Advantages for the contractor

SMM7 successfully guarantees that the contractor is pricing a precisely specified scope of work by reducing their financial risk:

• Pricing certainty: Contractors can use the same information to understand the scope and type of the item they are pricing and to estimate its cost.
• Employing a standardized BOQ limits the contractor’s risk exposure to the rates they enter on the bill. Clear descriptions prevent claims based on a misunderstanding of the initial scope.
• Dealing with Uncertainty: SMM7 requires that quantities that cannot be precisely determined be expressed as approximations due to design uncertainty. By informing the contractor in advance that they may remeasure the item at billed prices, we can avoid conflicts over the job’s ultimate cost.

Advantages for clients

SMM7 offers the client a robust financial baseline along with an intuitive contract administration system.

• Fair Comparison: Standardization promotes accurate and competitive tendering by evaluating every bidder against the same measured project.
• Basis for Dispute Resolution: The BOQ sets the contract price. SMM7 provides standard rates and measurements, enabling a reliable and agreed-upon benchmark to check and resolve any financial dispute.
• Contractual weight: SMM7 ensures the BOQ is always a contract document. This contractual weight applies not only to measured items but also to the preambles and rules defining work ‘deemed to be included’ (like cutting brickwork), preventing ambiguity about the full scope of responsibilities for a billed item.

Conclusion

The Standard Method of Measurement (SMM7) and its successors act as the “universal ruler and dictionary” for the construction world. By requiring clear descriptions, a consistent format, and the same measuring methods, these rules make sure that every part of a building project is measured, noted, and assessed using the same standards. Clear contracts, competitive pricing, open communication, and efficient dispute resolution rely on this foundation.

If you need a fully compliant, SMM7/NRM2-based BOQ for your next project, contact us. We deliver accurate, competitive, and risk-free estimates for contractors and developers.