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NRM2 takeoff rules to make BoQs audit ready for UK quantity surveyors

October 2, 2026
NRM2 takeoff rules to make BoQs audit ready for UK quantity surveyors

Producing a compliant NRM2 takeoff means measuring in metric units using the tabulated rules in Part 3, structuring your Bill of Quantities in the elemental, work section or work package order the project requires, and supporting it with preambles, provisional sums and a schedule of construction risks. This guide sets out the rules, the common measurement cases, and a workflow that produces an audit ready BQ.

TL;DR:

  • Using the correct NRM2 structure and ordering, such as elemental, work section, or work package, is crucial to ensure consistency and traceability in the bill.
  • Metric units are mandatory for measurements, with imperial units only included in parentheses if specifically requested, and symbols must be used consistently throughout.
  • Items are ordered by measurement type—cubic, square, linear, then enumerated—and labor-only items are usually listed before mixed categories to highlight cost priorities.
  • Provisional sums, contractor designed works, and construction risk allowances must be clearly separated from firm measured quantities to avoid ambiguity during tendering.
  • Digital tools can support measurement but do not replace the surveyor's judgment in applying NRM2 rules and recording assumptions throughout the takeoff process.
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Table of Contents

What NRM2 covers and how it fits the NRM suite

NRM2 is the RICS volume that sets out detailed rules for measuring and describing building works so that quantity surveyors can prepare Bills of Quantities and quantified schedules for tendering. It sits within a three part suite published by RICS, each volume serving a distinct stage of cost management.

NRM1 governs order of cost estimating and elemental cost planning, used from feasibility through to detailed design. NRM3 deals with order of cost estimating and cost planning for building maintenance works. NRM2 takes over once the design is developed enough to produce detailed measured quantities for tender documentation, which typically aligns with RIBA Plan of Work stages 4 and 5.

That positioning matters in practice. An elemental cost plan built under NRM1 during design development should translate cleanly into the elemental structure used for measured work under NRM2, so the cost control narrative stays consistent from early estimate to final account. Practitioners commonly carry the NRM1 elemental breakdown straight into the NRM2 measured output, which also supports links to international frameworks such as ICMS where a project requires them, as noted in guidance on NRM2 BQ breakdown structures.

The practical consequence for anyone compiling measured work is straightforward:

  • Confirm which NRM volume applies to the current work stage before you start measuring.
  • Use the elemental structure from the cost plan as your starting framework for the BQ.
  • Apply the tabulated rules in Part 3 of NRM2 consistently across every work section.
  • Keep the measurement basis traceable back to the drawings and specification you worked from.

Getting this sequencing right avoids the common problem of a BQ that duplicates or contradicts the cost plan it is meant to refine.

Units, symbols and basic conventions you must apply

NRM2 requires metric measurement as the primary record for every item. Imperial units may appear, but only in parentheses alongside the metric figure, and only where the employer has specifically asked for them, according to an academic extract of NRM2's measurement conventions.

Standard unit symbols recur throughout the BQ, and consistency is what makes a bill auditable:

  • m, m2 and m3 for linear, square and cubic measurement.
  • mm for small dimensions such as thicknesses and tolerances.
  • nr for enumerated items.
  • kg and t for mass, kW for rated power.

Dimensions must be recorded in the standard order of length, width and height. Where trade terminology uses a different word for one of these, such as 'depth' in joinery, NRM2 guidance notes that the surveyor should state explicitly which physical dimension that term refers to, avoiding ambiguity for anyone pricing the item later.

Where a description departs from a standard convention, flag it clearly rather than leaving it implicit. A note such as 'measured over insulation thickness' or 'dimensions include tolerance for fixing' costs a line of text and can prevent a dispute at final account stage.

Pro Tip: Keep a single conventions note at the front of the bill listing any non-standard usage, so every tenderer reads it the same way.

Bill of Quantities structure and ordering rules

NRM2 supports three principal BQ breakdown structures, and the choice affects how a reader navigates the bill and how contractors price it.

  1. Elemental BQs follow the same elemental order used in NRM1 cost planning, grouping measured items by building element such as substructure, frame or external walls.
  2. Work section BQs group items by trade or specification section, which suits project where subcontractor packages map directly to those trades.
  3. Work package BQs group items by the procurement packages actually being let, which is common on larger or phased contracts.

Within whichever structure is chosen, NRM2 sets a consistent internal order for items belonging to the same element or section: cubic items first, then square, then linear, then enumerated, then itemised, according to guidance on NRM2 BQ breakdown structures and ordering. Where labour only and labour-and-materials items both occur, labour only items are generally listed first, and items are then ordered by value within their category so the highest value work appears where it draws attention.

Summaries sit at the end of each section, collating totals without repeating descriptions. Preambles precede the measured items they govern, setting out assumptions that apply across a section rather than repeating them item by item. Contractor designed works are listed separately, after the directly measured work, because NRM2 requires them to carry a price analysis rather than a simple rate. Provisional sums, similarly, sit apart from firm measured quantities so a reader can immediately see which figures are fixed and which remain to be finalised.

Illustration of separated BoQ section layers

Writing unambiguous descriptions, preambles and codification

A measured item is only as good as its description. NRM2 expects each item to identify location, extent, method where it affects price, material and finish, enough detail that two contractors pricing independently would arrive at comparable figures.

Good descriptions share a few habits:

  • State the location and extent first, so the reader immediately knows what part of the building is covered.
  • Name the material and finish precisely rather than relying on a drawing reference alone.
  • Include any method detail that materially affects pricing, such as access constraints or sequencing.
  • Avoid repeating information already covered in the preamble for that section.

Preambles exist precisely to stop that repetition. A well written preamble sets out standards, workmanship clauses and general assumptions once for an entire work section, leaving individual item descriptions free to focus on what varies from item to item: quantity, specific location and any exception to the general rule.

Codification then ties the whole bill together. Consistent numbering that mirrors the NRM2 tabulated rule references, cross-referenced where an item relates to another section, lets anyone using the bill trace a figure back to its measurement basis without guesswork. A detailed explainer on how NRM2 supports consistent Bills of Quantities covers this in more depth for readers building their first bill from scratch.

Measuring common item types with worked examples

The tabulated rules in NRM2 set out, trade by trade, whether an item is measured by volume, area, length or number, and what is included or excluded in that measurement. Four unit types cover most measured work.

  1. Cubic items (m3) apply to bulk work such as concrete, excavation and filling, measured net as built unless the rules for that trade state otherwise.
  2. Square items (m2) apply to finishes, cladding and similar surface work, generally measured over the full area with deductions only for openings above a stated size.
  3. Linear items (m) apply to skirtings, edgings and similar continuous work, measured along the run with girth or cross section noted in the description.
  4. Enumerated items (nr) apply to discrete components such as doors, sanitary fittings or ironmongery, counted individually with a description covering type and fixing method.

A worked example makes the volume rule concrete. Say a ground floor slab measures 12 metres by 8 metres at 150 millimetres thick. The measured volume is 12 x 8 x 0.15, giving 14.4 m3. NRM2's tabulated rules for in-situ concrete generally require this to be measured net, excluding any allowance for formwork or reinforcement, which are measured separately under their own rules. The description should record the mix specification and the thickness, since both affect pricing even though neither changes the measured quantity itself.

A second example covers area measurement with a practical wrinkle. Take a bathroom floor of 6 m2 to be tiled. NRM2 measures the tiled area net, over the full floor, with any allowance for wastage or edge cuts treated as a pricing matter for the contractor rather than an addition to the measured quantity. The item description should specify the tile size and fixing method, and the measured 6 m2 figure sits in the BQ under the square items group for that room, ahead of any linear edging or enumerated fittings in the same section. A worked structural steel example, covering how enumerated connections and linear member lengths interact in one bill, is set out in a separate structural steel takeoff guide for readers who want a second trade worked through in full, and a tiling-specific walk-through appears in a step by step tiling takeoff example.

Pro Tip: Record the raw dimensions alongside the final quantity in your working papers, not just the result, so a reviewer can check the arithmetic without remeasuring the drawing.

Non-measurable work, provisional sums and construction risk

Not every item in a project can be measured precisely at tender stage, and NRM2 gives clear routes for handling that uncertainty rather than leaving it buried in a single rate.

  • Use provisional sums for work that is known to be required but cannot yet be designed or measured in detail, keeping them in a separate list rather than mixed into firm quantities.
  • Treat genuinely undefined risk allowances as contingency, kept distinct from provisional sums so a reader can see which figure covers known scope and which covers uncertainty.
  • List contractor designed works after the directly measured items, since NRM2 requires a price analysis for this category rather than a conventional rate against a measured quantity.
  • Prepare a schedule of construction risks, setting out risks that the employer intends to transfer to the contractor, and place it within the tender documentation alongside the preliminaries.

There is some live debate in the profession about how far this should go. RICS commentary has noted discussion around measuring earthwork support and working space explicitly, rather than leaving them to an implicit allowance in the contractor's rates, with some practitioners arguing this reduces contractor risk and pricing disputes, according to RICS journal coverage of the NRM update. Where a project has particular ground conditions or sequencing risk, it is worth deciding early which approach your bill will take and stating that decision in the preamble.

Practical takeoff workflow: step by step best practice

A consistent workflow is what keeps a large bill accurate and defensible under scrutiny.

  1. Confirm the basis before measuring. Check the drawing revision status, the RIBA work stage, and gather structural, mechanical and electrical input so you are not measuring against superseded information.
  2. Fix the BQ structure early. Decide between elemental, work section or work package breakdown before you start, so items do not need reordering later.
  3. Measure using the tabulated rules consistently. Apply the same interpretation of inclusions and exclusions across every section, and note any assumption in the preamble rather than varying the rule silently.
  4. Codify as you go. Number items to mirror the relevant NRM2 rule references, so cross-checking against the standard is straightforward.
  5. Separate provisional and risk items clearly. Keep these out of the firm measured totals so the bill's status is unambiguous to a tenderer.
  6. Cross-check totals before issue. Reconcile section totals against the cost plan, verify the schedule of construction risks is complete, and record who reviewed and approved the final bill.

That last step is where audit trails matter most. A bill that can show who measured an item, from which drawing revision, and who checked it, stands up far better to post-contract scrutiny than one where the working papers have been discarded. A practical guide to preparing PDF drawings for measurement covers the drawing preparation step in more detail for anyone setting up this workflow from scratch.

Pro Tip: Build your QA checklist around the BQ sections themselves, ticking off each one as measured, codified and cross-checked, rather than treating QA as a single pass at the end.

Templates, tools and digital workflows for NRM2 takeoffs

RICS publishes the NRM2 standard itself alongside supporting Excel appendices intended to help practitioners apply the rules consistently, available directly from the RICS standards page. These appendices give a structured starting point for preliminaries pricing schedules and other recurring BQ sections, rather than requiring every firm to build its own template from nothing.

Beyond the official templates, several categories of software support the measurement process including Building Maintenance Software for UK contractors that integrates maintenance scheduling with cost planning, aiding in ongoing cost control and data exchange between BoQs and facilities management.

  • Digital takeoff tools let a surveyor measure directly from a PDF drawing on screen, recording dimensions electronically rather than by hand.
  • BIM extractors pull geometric data from a building information model to support quantity extraction, an approach documented in academic and conference literature on automating BIM quantity takeoff alongside UK measurement conventions.
  • BoQ exporters convert measured data into a formatted bill, structured broadly along the lines this article has described.

Some software platforms read construction drawings and produce a draft Bill of Quantities for a quantity surveyor to review and sign off. As with any digital tool, the professional judgement involved in applying NRM2 correctly, and in recording the assumptions behind each measured item, stays with the surveyor. A broader look at the software categories available to UK firms is covered in a guide to quantity takeoff software.

Sources

FAQ

What is NRM1 and NRM2?

NRM1 covers order of cost estimating and elemental cost planning, used from early feasibility through detailed design. NRM2, set out in NRM 2: Detailed measurement for building works, covers detailed measurement for producing Bills of Quantities once the design is developed enough for tender documentation.

Which units does NRM2 require for measured items?

NRM2 requires metric units as the primary system of measurement, using standard symbols such as m, m2, m3, mm and nr. Imperial units may only appear in parentheses alongside the metric figure, and only where the employer has specifically requested them.

How should items be ordered within an NRM2 Bill of Quantities?

Within each element or work section, NRM2 orders items as cubic, then square, then linear, then enumerated, then itemised, according to guidance on NRM2 BQ breakdown structures. Labour only items are generally listed ahead of labour and materials items within the same category.

Where do provisional sums and contractor designed works sit in the bill?

Provisional sums are kept in a separate list, distinct from firm measured quantities, so a reader can see clearly what is confirmed and what remains uncertain. Contractor designed works are listed after directly measured items, since NRM2 requires them to carry a price analysis rather than a conventional measured rate.

Can software produce an NRM2 compliant Bill of Quantities automatically?

Software can extract geometry from drawings or models and draft a structured bill, but applying NRM2's tabulated rules correctly and recording the assumptions behind each item remains a task for the quantity surveyor. Platforms such as QuantiFlow read construction drawings and produce a draft Bill of Quantities for a surveyor to review and sign off, rather than replacing that professional review.

This article is for general information only and is not professional, legal or commercial advice. Quantity surveying decisions should be taken by a qualified professional with reference to the specific project, drawings and contract in question. Content is produced with AI assistance and reviewed before publication. QuantiFlow Ltd accepts no liability for reliance on it.