Quantity Surveying Reference
How construction work is measured and priced — the rules that decide what gets counted, what is deemed included in a rate, and how a unit rate is built up from its parts. The arithmetic is the easy half; the conventions are where money is won and lost.
Standard methods of measurement
A method of measurement is the rulebook that makes two tenders comparable. It fixes the unit each item is measured in, what the rate is deemed to cover, and which small items are ignored rather than counted. Without one agreed, two competent surveyors will produce different quantities from the same drawing and neither will be wrong.
The main families
| Document | Where it is used | Covers |
|---|---|---|
| IS 1200 (multi-part) | India, and widely referenced across South Asia | Building and civil engineering works, one part per trade — earthwork, concrete, brickwork, and so on |
| NRM (New Rules of Measurement) | United Kingdom | Order of cost estimating, detailed measurement for building works, and the maintenance works suite |
| SMM7 | United Kingdom — superseded by NRM but still met on older contracts | Building works |
| CESMM | United Kingdom and international civil engineering | Civil engineering works, used with the ICE/NEC family of contracts |
| POMI | International, particularly the Gulf | Building works; the Principles of Measurement (International) |
Of these, only IS 1200 is openly published, so it is the only one this page quotes clause by clause. The others are named at document level; check the governing document for your contract rather than assuming the rules below transfer.
General measurement rules
These carry across every trade in IS 1200 and are the first thing to agree on any project.
Measure net, in decimal, as fixed in place
Work is measured net as fixed in position — the finished quantity in the building, not the quantity of material that has to be bought. Waste, offcuts and breakage belong in the rate, not in the measured quantity.
| Quantity | Worked out to the nearest |
|---|---|
| Each dimension | 0.01 m |
| Areas | 0.01 m² |
| Cubical contents | 0.01 m³ |
Booking order. Dimensions are booked consistently in the sequence length, then breadth or width, then height or depth or thickness. Keeping to the order is what lets someone else check your dimension paper without re-reading the drawing.
Source: IS 1200 (Part 1):1992 clauses 2.2 and 2.3, and IS 1200 (Part III):1976 clauses 2.2 and 2.3 — the same rules appear in both. Verified against the standards as published at law.resource.org.
What a rate is deemed to include
A description of an item is held to include, unless stated otherwise, conveyance, delivery, handling, unloading, storing, waste and the return of packings. Pricing those separately is double-counting.
For earthwork, these are not measured separately and are deemed covered by the main item:
- Setting out works and profiles
- Site clearance, such as cleaning grass and vegetation
- Unauthorised battering or benching of excavation
- Forming or leaving "dead men" and "tell tales" in borrow pits, and removing them after measurement
- Forming or leaving steps in the sides of deep excavation, and removing them after measurement
- Excavation for the insertion of planking and strutting
- Removing slips or falls in excavations, unless otherwise specified
- Bailing out or pumping of rainwater from excavation
Special pumping and well-point dewatering are the exception — they are measured separately, in kW-hours or HP-hours, against a specific provision made for the purpose.
Source: IS 1200 (Part 1):1992 clauses 2.6 and 2.7; IS 1200 (Part III):1976 clause 2.4.
What is and is not deducted
The single most disputed area in measurement. The rules below are from the brickwork part of IS 1200 and are typical of the approach — small openings and small intrusions are ignored because chasing them costs more than they are worth.
No deduction, and no addition, is made for
| Item | Threshold |
|---|---|
| Openings in brickwork | up to 0.1 m² |
| Ends of dissimilar materials — joists, beams, lintels, posts, girders, rafters, purlins, trusses, corbels, steps | up to 0.1 m² in section |
| Wall plates, bed plates and bearings of slabs, chajjas and the like | thickness ≤ 10 cm, and bearing not over the full wall thickness |
| Cement concrete blocks for holdfasts and holding-down bolts | — |
| Iron fixtures — wall ties, holdfasts for doors and windows, pipes | pipes up to 300 mm diameter |
| Chases | section not exceeding 50 cm in girth |
| Smoke or air flues in brickwork | up to 0.2 m² sectional area — measured as solid |
In calculating the area of an opening, a separate lintel or sill is included with the size of the opening — but the end portions of the lintel are excluded, and the extra width of rebated reveals, if any, is also excluded. Getting this wrong moves openings across the 0.1 m² threshold in both directions.
Above the thresholds the deduction is made in full. Flues exceeding 0.2 m² in sectional area are deducted, and pargetting and coring are then measured separately in running metres, stating the flue size.
Source: IS 1200 (Part III):1976 clauses 3.1.1, 4.1.4 with its Note, and 4.1.5. Verified against the published standard.
Measure brickwork →How brickwork thickness is measured
| Wall thickness | Measured |
|---|---|
| One brick thick and less | Separately, in m², stating thickness |
| Over one brick, up to three bricks | In m³, in multiples of half a brick, mortar joints deemed included. A fraction up to half a brick is measured actual; a fraction exceeding half a brick counts as a full half-brick |
| More than three bricks thick | In m³, at the actual thickness of the wall |
Source: IS 1200 (Part III):1976 clauses 4.1, 4.1.1, 4.1.2 and 4.1.3.
The take-off workflow
Four stages, in order. Skipping the middle two is what makes a bill impossible to check later.
| Stage | What happens | Why it matters |
|---|---|---|
| 1. Taking off | Dimensions are scaled or read from the drawings and booked on dimension paper, with a description against each set | The audit trail. Anyone should be able to trace a quantity back to the drawing it came from |
| 2. Squaring | Dimensions are multiplied out to give areas and volumes | Kept separate from taking off so an arithmetic error cannot be mistaken for a measurement error |
| 3. Abstracting | Squared quantities for the same item are collected from all over the drawings and totalled under one heading | Where duplicates and omissions surface |
| 4. Billing | Abstracted totals are written into the bill in the order and wording of the method of measurement | What the contractor actually prices |
- Write "deduct" items explicitly rather than netting them off in your head — the next person cannot see subtraction that was never written down.
- Record what you assumed when a drawing was unclear. An assumption noted at take-off is a variation later; an assumption not noted is an argument.
- Never revise a dimension by overwriting it. Strike through and re-book, so the history stays visible.
Rate build-up
Rate analysis builds a unit rate from its constituents instead of adopting a market figure. It makes the rate defensible, and lets it be adjusted rationally when one component's price moves.
The five components
| Component | What it covers |
|---|---|
| Material | Quantity per unit of work, at delivered cost, including the wastage allowance appropriate to that material |
| Labour | Gangs and outputs — how much a crew produces in a day, converted to a cost per unit |
| Plant | Mixers, vibrators, hoists, pumps: owned or hired, charged by the hour or the day |
| Overhead | Site and head-office costs not attributable to one item, applied as a percentage |
| Profit | The contractor's margin, applied as a percentage on top |
1.54 m³ per m³ of finished concrete, split 1 : 1.5 : 3 over a ratio sum of 5.5.Cement =
1.54 × 1/5.5 = 0.280 m³ → 0.280 / 0.0347 ≈ 8.07 bagsSand =
1.54 × 1.5/5.5 = 0.420 m³ · Aggregate = 1.54 × 3/5.5 = 0.840 m³Add labour (mixing, placing, compacting, curing), plant (mixer and vibrator hours), then overhead and profit as percentages on the subtotal. The material figures above are fixed by the mix; only the prices and the outputs are local.
- Applying the mix ratio to wet volume instead of dry — it under-orders every material by about a third.
- Adding wastage twice: once in the measured quantity and again in the rate. It belongs in the rate.
- Applying profit to a subtotal that already includes profit on a sub-item.
Wastage allowances
Wastage belongs in the rate, not the measured quantity. These are the allowances commonly used; they are commercial conventions rather than code requirements, and any contract or company standard overrides them.
| Material | Typical allowance | Driven by |
|---|---|---|
| Bricks — straight walls | 5% | Handling breakage |
| Bricks — many corners or openings | 7–10% | Cutting |
| Tiles — plain rectangular room | 5% | Edge cuts |
| Tiles — diagonal laying or complex shape | 10–15% | Cutting angles |
| Reinforcement steel | 3–5% | Offcuts, laps beyond schedule |
| Cement | 2–3% | Bag handling, spillage |
| Concrete — ready-mix | 2–5% | Over-pour, spillage, formwork tolerance |
| Paint | 5–10% | Absorption on porous surfaces, roller loss |
Wastage belongs on the material that actually suffers it. Brick wastage is real; the cement and sand in the mortar are calculated on net volume and do not carry the same allowance. Applying one blanket percentage across every line of a take-off inflates the tender without making it any safer.
Bill of quantities structure
| Section | What sits there |
|---|---|
| Preliminaries | The cost of running the project rather than building it — site establishment, supervision, scaffolding, insurances, temporary services, programme-related costs |
| Measured works | The permanent work, by trade, in the order the method of measurement sets out |
| Provisional sums | Allowances for work that cannot yet be measured, to be expended and adjusted against actual cost |
| Prime cost sums | Allowances for goods or services from a nominated supplier or subcontractor |
| Dayworks | Rates for work instructed but not measurable against a bill item, priced on actual labour, plant and materials |
| Contingency | A sum held for the unforeseen, released only by instruction |
Preliminaries are largely time-related: extend the programme and much of the cost extends with it. Because they are not tied to a measured quantity, an extension of time claim usually turns into an argument about which prelims are time-related and which are fixed. Separating the two when the bill is written is far easier than reconstructing it afterwards.
How this page was sourced
Every clause number quoted above was read from IS 1200 as published openly by the Bureau of Indian Standards — Part 1 (Earthwork, 1992) and Part III (Brickwork, 1976) — rather than from a secondary source. Thresholds such as the 0.1 m² opening rule and the 0.2 m² flue rule are quoted as the standard states them.
NRM, SMM7, CESMM and POMI are not openly published, so they are named at document level only and no rule is attributed to them. Wastage allowances and rate build-up structure are commercial practice rather than code, and are labelled as such.
Free to quote and link. Suggested citation: QSCivilCalc (2026). Quantity Surveying Reference. https://qscivilcalc.com/quantity-surveying-resources/
