NRM 2 Practical Measurement Guide
Why NRM 2 Matters
The New Rules of Measurement 2 (NRM 2) is the RICS standard for detailed measurement of building works. It defines how every element of a building project is to be classified, described, measured, and presented in a bill of quantities. NRM 2 replaced the Standard Method of Measurement 7th edition (SMM7) and is the method used on the vast majority of traditionally procured UK building projects — typically those let under JCT contracts where the employer provides a full bill of quantities as part of the tender documentation.
For quantity surveyors at every career stage, fluency in NRM 2 is essential. Students preparing for the RICS APC must demonstrate competence in at least one method of measurement, and NRM 2 is the most commonly assessed. Practitioners preparing bills of quantities, pricing variations, or agreeing final accounts on building projects must apply NRM 2’s rules correctly — errors in measurement lead to pricing disputes, contractual claims, and loss of professional credibility. For a broader overview of all measurement standards including CESMM4 and POMI, see our article on Methods of Measurement in Construction.
This article provides a practical, work-section-by-work-section guide to measuring a building project under NRM 2, using a two-storey detached house as a running case study. It covers the key measurement rules, deemed inclusions, units of measurement, and common errors for each work section — and includes comparison tables showing what has changed from SMM7, for practitioners transitioning between the two methods.
The Case Study: A Two-Storey Detached House
To make this guide practical, all worked examples are based on a single project — a new-build, four-bedroom detached house of approximately 140 m² gross internal floor area (GIFA), with the following specification:
| Element | Specification |
|---|---|
| Footprint | 8.0 m × 9.0 m (72 m² ground floor) |
| Storeys | Two (ground and first floor, 2.4 m clear height each) |
| Foundations | Strip foundations to clay soil, 600 mm wide × 300 mm deep concrete on 150 mm blinding, 1.0 m below finished ground level |
| Ground floor | 150 mm insulated ground-bearing concrete slab, C30, with A393 mesh reinforcement, 1200-gauge DPM, 100 mm PIR insulation, 65 mm sand/cement screed |
| External walls | Cavity wall: 102.5 mm facing brick outer leaf, 100 mm full-fill mineral wool insulation, 100 mm dense concrete block inner leaf (7.0 N/mm²), 12.5 mm plasterboard on dabs |
| Internal walls | 100 mm lightweight concrete block (3.5 N/mm²) with 12.5 mm plasterboard both sides |
| First floor | 50 × 225 mm C16 softwood joists at 400 mm centres, 18 mm structural plywood deck |
| Roof | Trussed rafters at 600 mm centres, concrete interlocking tiles on breathable underlay, 35° pitch |
| Windows and doors | uPVC double-glazed windows; composite front door; softwood internal doors in softwood linings |
| Finishes | Emulsion to walls and ceilings; gloss to timber; ceramic tiles to kitchen and bathrooms |
The perimeter of the building is 34 m (2 × 8.0 m + 2 × 9.0 m). Internal partitions total approximately 28 m in linear run. The pitched roof area (both slopes) is approximately 100 m² on the rake. These dimensions will be used throughout the worked examples below.
NRM 2 Structure and Bill Format
How the Bill Is Organised
An NRM 2 bill of quantities follows a standard structure. Bill 1: Preliminaries (Work Section 1) covers the contractor’s project-wide costs — site establishment, management, temporary works, plant, insurances, and compliance. Bill 2: Measured Works (Work Sections 2–41) contains the measured construction items organised by work section. Additional sections cover risks (Section 42), provisional sums (Section 43), credits (Section 44), and daywork (Section 45).
Each measured item in the bill follows NRM 2’s tabulated format — a structured presentation with columns for the item to be measured, the unit of measurement, and a three-level classification hierarchy (Level 1: broad category; Level 2: material or type; Level 3: specific attributes such as thickness, grade, or finish). Supplementary information columns define deemed inclusions, deductions, and measurement conventions. This tabulated structure is one of NRM 2’s strengths — it provides a consistent, systematic framework that reduces ambiguity and supports both manual measurement and BIM-based quantity extraction.
Overheads and Profit
Under NRM 2, the contractor’s overheads and profit are embedded within the unit rates for measured work items — the rate the contractor inserts against each item in the bill should include their margin. However, for provisional sums and daywork, overheads and profit are stated separately as a percentage addition. This is a deliberate transparency measure — it allows the employer to see the contractor’s margin on work that has not yet been fully defined at tender stage.
Work Section 1: Preliminaries
What Preliminaries Cover
Preliminaries are the contractor’s project-wide costs that cannot be attributed to a specific measured work item. NRM 2 Section 1 provides a comprehensive framework for describing and pricing these costs, organised into categories including site accommodation (offices, welfare facilities, storage), temporary services (electricity, water, telecommunications), plant and equipment (cranes, scaffolding, hoisting), temporary works (hoardings, fencing, protection), site management (site manager, foreman, safety officer), insurances and bonds, and testing and commissioning.
On a residential house project, typical preliminaries items include site fencing and hoarding, temporary electricity and water supply, scaffolding to the full perimeter and height of the building, skip hire and waste removal, site welfare facilities, and the site foreman’s time for the contract duration. For a house with a 20-week programme, preliminaries typically represent 8 to 15 per cent of the measured works total.
NRM 2 vs SMM7: Preliminaries
| Aspect | NRM 2 | SMM7 |
|---|---|---|
| Structure | Detailed categorised framework aligned to NRM 1 cost elements | Less structured; based on CAWS Section A |
| Provisional sums | Explicitly stated as exclusive of overheads and profit | Treatment of O&P on provisional sums less clearly defined |
| RIBA alignment | Mapped to RIBA Plan of Work stages | No explicit RIBA stage alignment |
Work Section 5: Excavation and Filling
Measurement Rules
Excavation is measured in cubic metres (m³), classified by the type of material (topsoil, natural ground, rock, artificial hard material) and by the depth below the existing ground level. NRM 2 uses depth ranges — typically not exceeding 0.25 m (topsoil strip), not exceeding 1.00 m, 1.00–2.00 m, 2.00–4.00 m, and so on — because the cost of excavation increases significantly with depth due to the need for temporary support, more complex plant access, and disposal logistics.
Filling is measured separately in cubic metres, classified by material type (excavated material, imported granular fill, hardcore, sand blinding) and by method of deposition (filling to excavations, filling to make up levels, filling to trenches).
Worked Example: Strip Foundations
For our case study house, the strip foundations run around the full 34 m perimeter plus internal load-bearing walls (approximately 12 m). Total foundation trench length: 46 m.
| NRM 2 Item | Description | Unit | Quantity |
|---|---|---|---|
| 5.1 | Excavation of topsoil; average 150 mm deep; for preservation | m³ | 13.50 |
| 5.4 | Excavation; foundation trenches; not exceeding 1.00 m deep; commencing from reduced level | m³ | 27.60 |
| 5.10 | Disposal of excavated material; off site | m³ | 27.60 |
| 5.12 | Filling to excavations; selected excavated material; compacted | m³ | 13.80 |
Calculation notes: Topsoil strip = 90 m² site area × 0.15 m = 13.50 m³. Trench excavation = 46 m × 0.60 m wide × 1.00 m deep = 27.60 m³. Backfill = 46 m × 0.60 m × 0.50 m (above foundation) = 13.80 m³.
NRM 2 vs SMM7: Excavation
| Aspect | NRM 2 | SMM7 |
|---|---|---|
| Classification | Excavation classified by type and depth range from reduced level | Similar depth classifications but referenced from original ground level |
| Disposal | Disposal measured as a separate item (on site or off site) | Disposal deemed included unless removal off site stated |
| Earthwork support | Measured where required; classified by depth and type | Deemed included in excavation unless exceeding specified depths |
| Working space | Measured separately where required for below-ground construction | Not separately identified in most cases |
Work Section 11: In-Situ Concrete Works
Measurement Rules
In-situ concrete is measured in cubic metres (m³), classified by concrete grade (e.g. C25, C30, C32/40), type of cement, maximum aggregate size, and the building element in which it is placed (foundations, ground slabs, beams, columns, walls, suspended slabs). Formwork is measured separately in square metres (m²), classified by surface type (plane, curved), element (sides of foundations, soffit of slabs, sides of beams), and height range. Reinforcement is measured separately in tonnes (t) or kilograms (kg), classified by type (mild steel, high-yield steel) and bar diameter or mesh reference.
The key principle is that concrete, formwork, and reinforcement are always measured as three separate items — never combined. This allows the contractor to price each element based on its actual cost (concrete supply, formwork labour and materials, reinforcement supply and fixing) rather than a composite rate that obscures the cost drivers.
Deemed Inclusions
Under NRM 2, the concrete item is deemed to include placing, compacting, vibrating, and curing — the contractor’s rate for the concrete must cover not just the material but the labour and plant for placing. Formwork items are deemed to include erecting, striking, and any necessary propping during the curing period. Reinforcement items are deemed to include cutting, bending, fixing, and tying — but not the spacers (which are measured separately if required by the specification).
Worked Example: Ground Floor Slab
For our case study house, the ground floor slab is 72 m² (8.0 m × 9.0 m internal), 150 mm thick, C30 concrete with A393 mesh reinforcement.
| NRM 2 Item | Description | Unit | Quantity |
|---|---|---|---|
| 11.1 | In-situ concrete; C30; 20 mm aggregate; ground-bearing slab; thickness 150 mm | m³ | 10.80 |
| 11.8 | Formwork; plane; edges of ground slab; height not exceeding 250 mm | m² | 5.10 |
| 11.14 | Reinforcement; fabric; A393 mesh; minimum laps 400 mm | m² | 79.20 |
Calculation notes: Concrete volume = 72 m² × 0.15 m = 10.80 m³. Edge formwork = 34 m perimeter × 0.15 m = 5.10 m². Mesh reinforcement = 72 m² × 1.10 (10% laps allowance) = 79.20 m². Note: fabric reinforcement may be measured in m² (area of mesh) rather than tonnes under NRM 2, depending on the classification adopted.
NRM 2 vs SMM7: Concrete
| Aspect | NRM 2 | SMM7 |
|---|---|---|
| Concrete classification | Classified by grade, aggregate size, and element type (foundation, slab, beam, column) | Similar but classified primarily by prescribed/designed mix and element type |
| Formwork classification | Plane or curved; classified by element and height range; width of soffit classified | Similar but with different height range thresholds in some cases |
| Reinforcement unit | Tonnes (t) for bar reinforcement; m² or t for fabric | Tonnes for all reinforcement types |
| Sundries | Items such as construction joints, waterstops, and surface treatments measured separately | Some sundries deemed included that NRM 2 measures separately |
Work Section 14: Masonry
Measurement Rules
Walling is measured in square metres (m²), measured on the centre line of the wall. This is an important convention — the QS measures the area of the wall face (length × height) but uses the centre line length, not the internal or external face length. For a cavity wall, the outer leaf and inner leaf are measured separately, each on its own centre line.
Masonry items are classified by material (clay brick, concrete block, natural stone), bond type (stretcher, Flemish, English), strength grade (for blocks: 3.5 N/mm², 7.0 N/mm²), and thickness (102.5 mm brick, 100 mm block, 140 mm block). The mortar specification (mix, joint profile) is stated in the item description. Cavity insulation is measured as a separate item in square metres.
Key Rules for Openings
NRM 2 states that no deductions are made for openings not exceeding 0.50 m². For openings exceeding 0.50 m², the full opening area is deducted. Lintels, sills, and reveals are measured separately — lintels as linear metres, reveals as linear metres (stating the width and depth of the reveal), and sills as linear metres. This treatment of openings is a critical area for accurate measurement — failure to deduct correctly or to measure the associated items (lintels, sills, reveals, cavity closers) is one of the most common errors in masonry measurement.
Worked Example: External Walls (Ground Floor)
Ground floor external walls: 34 m perimeter × 2.70 m height (2.40 m clear + 0.30 m for floor zone) = 91.80 m² gross. Assume six window openings (1.20 m × 1.20 m = 1.44 m² each) and two door openings (0.90 m × 2.10 m = 1.89 m² each). All openings exceed 0.50 m² so are deducted.
| NRM 2 Item | Description | Unit | Quantity |
|---|---|---|---|
| 14.1 | Walls; facing brick; stretcher bond; 102.5 mm thick; in cement:lime:sand 1:1:6 mortar; flush pointed | m² | 79.92 |
| 14.1 | Walls; dense concrete block; 7.0 N/mm²; 100 mm thick; in cement:sand 1:4 mortar | m² | 79.92 |
| 14.8 | Cavity insulation; 100 mm full-fill mineral wool batts; to cavity walls | m² | 79.92 |
| 14.6 | Lintels; prestressed concrete; 100 × 65 mm; to suit 1200 mm openings | m | 7.20 |
| 14.6 | Lintels; prestressed concrete; 100 × 65 mm; to suit 900 mm openings | m | 1.80 |
Calculation notes: Gross wall area = 91.80 m². Deductions: 6 windows (6 × 1.44 = 8.64 m²) + 2 doors (2 × 1.89 = 3.78 m²) = 12.42 m² deducted. Net area = 91.80 − 12.42 = 79.38 m², rounded to 79.92 m² to include returns and adjustments. Each leaf measured separately at the same area. Lintels: 6 windows × 1.20 m = 7.20 m; 2 doors × 0.90 m = 1.80 m.
NRM 2 vs SMM7: Masonry
| Aspect | NRM 2 | SMM7 |
|---|---|---|
| Opening deductions | No deduction for openings ≤ 0.50 m² | No deduction for openings ≤ 0.10 m² (smaller threshold) |
| Reveals | Measured separately as linear metres; state width and depth | Deemed included in walling in most cases |
| Closing cavities | Measured separately; cavity closers enumerated | Closing cavities at jambs deemed included or described differently |
| Measurement basis | Centre line of wall | Centre line of wall (unchanged) |
| Isolated piers | Measured in linear metres where length on plan is less than 4× thickness | Similar rule but different threshold in some cases |
Work Section 16: Carpentry
Measurement Rules
Timber structural members (joists, rafters, purlins, wall plates, struts, braces) are measured in linear metres (m), classified by timber species and grade (e.g. C16 softwood, C24 softwood), cross-sectional size (e.g. 50 × 225 mm), and treatment (untreated, pressure-treated, fire-retardant). Sheet materials (plywood decking, chipboard, OSB) are measured in square metres (m²), classified by material, thickness, and grade.
All timber is deemed to be sawn unless the description states otherwise. Wrot (planed) timber is described separately and typically commands a higher rate due to the additional processing. Ironmongery and fixings associated with structural timber (joist hangers, framing anchors, truss clips) are measured separately — either enumerated (nr) or as an item.
Worked Example: First Floor Construction
First floor: 72 m² area. Joists at 400 mm centres spanning 4.0 m (half-span with intermediate support). Joists are 50 × 225 mm C16 softwood, pressure-treated. Decking is 18 mm structural plywood.
| NRM 2 Item | Description | Unit | Quantity |
|---|---|---|---|
| 16.1 | Structural softwood; C16; pressure-treated; 50 × 225 mm; floor joists | m | 180.00 |
| 16.3 | Sheet material; 18 mm structural plywood; grade C/D; flooring to joists | m² | 72.00 |
| 16.5 | Herringbone strutting; 50 × 50 mm softwood; between joists | m | 18.00 |
Calculation notes: Number of joists = 9.0 m ÷ 0.4 m + 1 = 24 joists, but measured as total linear metres: 24 joists × 4.0 m span = 96 m per half + trimming allowance. Alternatively for full span joists across 8.0 m: 9.0 m ÷ 0.4 m = approximately 23 joists × 8.0 m = 184 m, rounded to 180 m allowing for openings. Strutting at mid-span: 2 rows × 9.0 m = 18.0 m.
Work Section 18: Tile and Slate Roof Coverings
Measurement Rules
Roof coverings are measured in square metres (m²) on the rake (the actual sloped area, not the plan area). The classification includes the tile or slate type, material (concrete, clay, natural slate), size, profile, fixing method, and the underlay specification. Ridge and hip tiles are measured in linear metres (m). Valley tiles, verge tiles, and eaves fittings are measured in linear metres or enumerated as appropriate.
NRM 2 requires that the roof covering item is deemed to include the standard battens and any counter-battens required by the tile manufacturer’s fixing specification. The breathable underlay (or traditional felt) is measured as a separate item in square metres. Ventilation components (soffit vents, ridge vents, tile vents) are enumerated separately.
Worked Example: Pitched Roof
Roof: two slopes, each approximately 50 m² on the rake (total 100 m²). Ridge length: 9.0 m. Verge length: 16.0 m (2 gable ends × 2 slopes × 4.0 m rafter length).
| NRM 2 Item | Description | Unit | Quantity |
|---|---|---|---|
| 18.1 | Roof coverings; concrete interlocking tiles; 420 × 330 mm; on 25 × 50 mm treated softwood battens at 340 mm gauge | m² | 100.00 |
| 18.3 | Underlay; breathable roofing membrane; Type LR; lapped 150 mm | m² | 105.00 |
| 18.4 | Ridge tiles; concrete half-round ridge; bedded and pointed in cement:sand 1:3 mortar | m | 9.00 |
| 18.5 | Verge tiles; concrete verge units; bedded | m | 16.00 |
| 18.7 | Eaves ventilation; continuous soffit strip vent; 10 mm opening | m | 18.00 |
Calculation notes: Underlay area is 5% greater than tile area to allow for laps. Eaves length = 2 × 9.0 m = 18.0 m (both sides of roof).
Work Section 28: Finishings
Measurement Rules
Floor, wall, and ceiling finishes are measured in square metres (m²), classified by material (plasterboard, cement:sand render, ceramic tiles, vinyl flooring, carpet), substrate (to masonry, to concrete, to timber), thickness, and finish type. A critical NRM 2 rule is the distinction between general areas (width exceeding 600 mm) and narrow widths (not exceeding 600 mm) — narrow widths are measured separately in linear metres because they are more labour-intensive per unit area.
Screeds are measured in square metres, classified by mix (cement:sand, self-levelling compound), thickness, and substrate. Plasterboard linings are measured in square metres, classified by board type (standard, moisture-resistant, fire-resistant), thickness, number of layers, and method of fixing (on dabs, to battens, to studs).
Worked Example: Internal Finishes
| NRM 2 Item | Description | Unit | Quantity |
|---|---|---|---|
| 28.1 | Screed; cement:sand 1:3; 65 mm thick; to concrete base; steel-trowelled finish | m² | 72.00 |
| 28.3 | Plasterboard; 12.5 mm standard wallboard; on dabs to blockwork walls | m² | 245.00 |
| 28.3 | Plasterboard; 12.5 mm moisture-resistant board; on dabs to blockwork; to kitchen and bathrooms | m² | 48.00 |
| 28.5 | Skim coat; 3 mm thistle multi-finish plaster; to plasterboard | m² | 293.00 |
| 28.7 | Ceramic wall tiles; 300 × 200 mm; on adhesive bed; to walls above worktops and in bathrooms | m² | 28.00 |
Calculation notes: Plasterboard to walls = total internal wall area (external walls + partitions) less openings. Skim coat = total plasterboard area (walls + ceilings). Ceramic tiles measured to specific splashback and bathroom areas only.
Work Section 29: Decoration
Measurement Rules
Decoration (painting) is measured in square metres (m²) of the surface to be decorated, classified by the surface type (plaster, plasterboard, timber, metal), the paint system (emulsion, gloss, eggshell, masonry paint), and the number of coats. Decoration to general wall and ceiling surfaces is straightforward — the area corresponds to the finishes area. Decoration to timber (doors, frames, skirting, architraves) is measured in square metres of the painted surface or in linear metres for narrow items, depending on the item width.
Worked Example: Internal Decoration
| NRM 2 Item | Description | Unit | Quantity |
|---|---|---|---|
| 29.1 | Emulsion paint; two coats; to plastered walls | m² | 293.00 |
| 29.1 | Emulsion paint; two coats; to plastered ceilings | m² | 144.00 |
| 29.3 | Gloss paint; one undercoat, two finishing coats; to timber general surfaces; door frames and architraves | m² | 36.00 |
Calculation notes: Wall emulsion area = total skim coat area. Ceiling area = ground floor (72 m²) + first floor (72 m²) = 144 m². Timber = estimated area of door frames, architraves, and skirtings.
NRM 2 vs SMM7: Finishes and Decoration
| Aspect | NRM 2 | SMM7 |
|---|---|---|
| Narrow widths | Finishes not exceeding 600 mm wide measured separately in linear metres | Narrow widths threshold at 300 mm in some sections |
| Finishes vs decoration | Clear separation: Section 28 (applied finishes) and Section 29 (decoration/painting) | Similar separation but in differently numbered sections (M and N) |
| Classification | NRM 2 numeric work sections | SMM7 alphabetic CAWS references |
| Painting to timber | Classified by surface area; narrow items (≤ 300 mm girth) measured in linear metres | Similar but with different girth thresholds for isolated surfaces |
Summary Comparison: NRM 2 vs SMM7 Key Differences
The following table summarises the principal differences between NRM 2 and SMM7 across all work sections. QS professionals transitioning from SMM7 to NRM 2 should study these differences carefully — applying SMM7 rules to an NRM 2 bill will produce incorrect quantities and item descriptions.
| Feature | NRM 2 | SMM7 |
|---|---|---|
| Work sections | 41 numbered work sections | 22 alphabetic trade sections (CAWS) |
| Alignment | Aligned to RIBA Plan of Work and NRM 1 | Aligned to Common Arrangement of Work Sections (CAWS) |
| BIM compatibility | Tabulated format designed for digital extraction and BIM integration | Pre-BIM structure; manual measurement assumed |
| Opening deductions (masonry) | No deduction for openings ≤ 0.50 m² | No deduction for openings ≤ 0.10 m² |
| Reveals and sills | Measured separately as linear metres | Largely deemed included in walling item |
| Disposal of excavated material | Measured as a separate item | Deemed included unless stated otherwise |
| Narrow width finishes | Threshold: ≤ 600 mm measured separately | Threshold: ≤ 300 mm in some sections |
| Overheads and profit | Embedded in rates; separate % on provisional sums | Similar but less explicit separation |
| Preliminaries | Comprehensive, structured framework in Section 1 | Less structured presentation |
| Cost planning link | Direct alignment with NRM 1 elemental structure and BCIS | No direct alignment with cost planning framework |
Common Errors in NRM 2 Measurement
The Mistakes That Cost Money
Measurement errors in bills of quantities lead to incorrect tenders, pricing disputes, and claims during the contract. The following are the most common errors that QS professionals make when measuring under NRM 2 — whether from inexperience, carelessness, or confusion with SMM7 rules.
Mixing NRM 2 and SMM7 rules. Practitioners who learned their craft under SMM7 may unconsciously apply SMM7 conventions when preparing an NRM 2 bill. The most common instance is using the 0.10 m² opening deduction threshold (SMM7) instead of 0.50 m² (NRM 2) for masonry — this produces materially different net wall areas and affects the quantities for reveals, lintels, and cavity closers.
Failing to measure items separately. NRM 2 requires certain items to be measured separately that SMM7 deemed included. Reveals and sills in masonry are the classic example — under NRM 2, these must be measured in linear metres with their width and depth stated. Omitting these items means the contractor has no priced item for the work, creating a potential variation or claim.
Incorrect unit of measurement. Using the wrong unit — for example, measuring reinforcement in square metres when the classification requires tonnes, or measuring lintels per number rather than per linear metre — produces items that cannot be priced accurately and may be rejected by tenderers.
Incomplete item descriptions. NRM 2’s three-level classification requires sufficient detail for the contractor to price the item. A description of “in-situ concrete to foundations” is inadequate — the item must state the concrete grade, aggregate size, and element type. Incomplete descriptions lead to qualifications in tenders and disputes about what is included.
Not separating concrete, formwork, and reinforcement. Combining these into a single “reinforced concrete” item is a fundamental error. NRM 2 requires three separate measured items — each with its own unit, classification, and rate. This separation is essential because the cost drivers for concrete (material and placement), formwork (labour and materials), and reinforcement (material and fixing) are different and must be priced independently.
Ignoring the narrow width rule for finishes. Finishes not exceeding 600 mm wide must be measured separately from general areas. Measuring a 500 mm wide tiled splashback as part of the general wall tiling area will understate the cost — narrow widths are more labour-intensive and command a higher rate per square metre.
Practical Tips for Accurate NRM 2 Measurement
The following practices will improve measurement accuracy and reduce the risk of errors and disputes.
Always work from the tabulated rules. Do not measure from memory or assumption. For every item, refer to the relevant NRM 2 work section and check the unit of measurement, classification requirements, deemed inclusions, and supplementary rules. The tabulated format is designed to be used as a working reference — keep it open while measuring.
Check your deduction rules. Before deducting any opening, verify whether it exceeds the relevant threshold. For masonry (0.50 m²), finishes, and decoration, the thresholds differ — do not assume the same rule applies across all work sections.
Describe items fully. Use the three-level classification to build a complete item description. Level 1 (broad category) + Level 2 (material/type) + Level 3 (specific attributes) = a description that the contractor can price with confidence. If in doubt, include more detail rather than less.
Cross-check quantities against the cost plan. If the NRM 2 bill quantities produce a total that differs significantly from the NRM 1 cost plan, investigate the discrepancy. The two documents should be broadly aligned — NRM 1 and NRM 2 use the same elemental structure, so large variances indicate a potential measurement error or a change in scope that has not been captured.
Use BIM where available. Where a BIM model is available, use it to extract geometric quantities and cross-check against your manual measurement. BIM does not replace the QS’s judgement in classifying and describing items under NRM 2, but it provides a powerful check on the quantities themselves — and significantly reduces the risk of arithmetic error.
What Comes Next
This article has provided a practical, work-section-by-work-section guide to NRM 2 measurement using a residential house case study. Future articles on ProQS.site will take each work section deeper — with detailed measurement exercises, further worked examples for commercial and civil engineering projects, and guidance on using NRM 2 with BIM-based quantity extraction. For practitioners preparing for the RICS APC, measurement competence under NRM 2 is a mandatory requirement — the worked examples in this article provide a foundation, but there is no substitute for practice. Measure a building. Then measure it again. The rules become second nature only through repetition.