The measurement book is the primary record of what was actually built. Everything downstream — the abstract, the running account bill, the memorandum of payments, the final bill — is derived from it, and none of those documents can be more accurate than the MB they came from.
CPWD has moved this record from a bound paper book to a computerized measurement book (CMB), entered through the departmental e-MB module, with electronic reporting made mandatory across field offices. The arithmetic has not changed. What has changed is that the format is now fixed by the system rather than by whoever was holding the pen, and that entries become immutable at a defined point instead of being correctable with an initialled overwriting.
What a computerized MB has to contain
A CMB is not a spreadsheet of quantities. It is a structured record in which each measured quantity can be traced back to the physical dimensions it came from, the date it was taken, and the person who took it. Strip any of those out and it stops being a measurement book.
- The agreement item it measures — by item number and full description, matching the agreement.
- The individual measurement entries, each with its own dimensions rather than a pre-totalled figure.
- The date of measurement for each entry.
- Deductions, shown as their own entries rather than netted off silently.
- The running total per item, and the quantity carried forward from previous bills.
- Test check entries by the supervising officer, with the percentage checked.
- The identity of the person recording and the officer checking.
The dimensions are the point. A quantity entered as a single number is unverifiable — nobody can re-measure it against the drawing — and an MB full of bare totals is the fastest route to an audit objection.
The measurement table columns
The standard CPWD measurement table is a set of multipliers and dimensions that resolve to one quantity per row. The columns below are the ones a computerized MB carries.
| Column | Meaning | Notes |
|---|---|---|
| S. No. | Serial number of the row within this item's table | Restarts per item, not per book |
| Description | What is being measured and where — "Plinth beam PB1, Room A, north wall" | The location matters as much as the member; it is what makes a re-measure possible |
| Nos | Number of identical members | The first multiplier |
| Nos (2) | A second multiplier where the geometry needs one | Left as 1 when unused, not blank |
| L | Length | Blank is treated as 1, so an area measurement does not need a dummy value |
| B | Breadth or width | Same convention |
| H / D | Height, depth or thickness | Same convention |
| Quantity | Nos × Nos(2) × L × B × H | Computed, never typed — a typed quantity is unverifiable |
| Unit | cum, sqm, metre, nos, quintal … | Must match the agreement item's unit |
| Date | Date the measurement was taken | Backdating is recorded, not prevented — the trail is the control |
| Remarks | Anything a checking officer needs to know | Where drawing revisions and site instructions get referenced |
A row measuring an area rather than a volume simply leaves H blank; the calculation treats the blank as 1 rather than as zero. That convention is what lets one table shape carry LBH, LB, L-only, number and weight measurements without a separate format for each.
Worked measurement: RCC plinth beams
Take the plinth beams of a small building, 230 mm wide and 450 mm deep, in M25. Two beams of 4.20 m and four of 3.60 m, with the beam running into six columns that must be deducted so the concrete is not paid for twice.
| S.No | Description | Nos | L (m) | B (m) | H (m) | Qty (cum) |
|---|---|---|---|---|---|---|
| 1 | Plinth beam PB1 — grid A1–A2, B1–B2 | 2 | 4.20 | 0.23 | 0.45 | 0.8694 |
| 2 | Plinth beam PB2 — grid A2–A3, B2–B3, C1–C2, C2–C3 | 4 | 3.60 | 0.23 | 0.45 | 1.4904 |
| 3 | Deduct — beam length inside column sections | 6 | 0.23 | 0.23 | 0.45 | −0.1428 |
| Total | 2.2170 |
Note that the rows are carried to four decimals and only the total is rounded — 2.217 cum. Rounding each row to three first gives 2.216, and on a bill with a hundred rows that drift is no longer invisible. Round once, at the end.
The deduction is a row of its own, with its own dimensions, not a number subtracted from row 1. That is what lets a checking officer verify the deduction independently — and what stops the same deduction being applied twice in a later bill.
Deductions
Deductions follow the measurement rules of the relevant CPWD specification for the item, and those rules are not uniform — some items ignore openings below a stated area, others deduct everything. Two practical rules hold regardless of item:
- Record the deduction as a separate, signed entry with its own dimensions. Never net it into the positive row.
- Deduct in the bill in which the corresponding positive quantity was claimed. A deduction that arrives one bill late means the previous bill overpaid, which is an adjustment rather than a correction and reads badly in audit.
Part rates
Sometimes work is measured and payable, but not at the full agreement rate — the item is complete except for a finishing operation, or it has been accepted with a defect at a reduced rate. That is a part rate.
A part rate is applied to a named subset of measurement rows, not to the whole item. The rest of the item continues at the full agreement rate in the same bill. Recording it any other way — reducing the agreement rate for the whole item, or reducing the quantity to fake the value — destroys the quantity record, and the quantity record is the thing the MB exists to protect.
Every part rate needs the reason and the authority recorded against it. "Reduced rate as per EE's instruction dated …" is a record; a lower number with no note is a discrepancy waiting to be found.
Deviation and the Schedule F limit
Quantities move. When the quantity of an item measured up to date exceeds the deviation limit set in Schedule F of the agreement — commonly 15%, but read your own agreement rather than assuming — the excess is no longer covered by the agreement rate as of right, and Clause 12 of the GCC governs what happens next.
A computerized MB should flag the crossing rather than block the measurement. The work was done; refusing to record it does not undo that. What has to exist is a recorded acceptance — the approval reference and the decision — sitting alongside the measurement, so that the bill can be passed with the deviation visible instead of buried.
Where the deviated quantity needs a fresh rate, that rate is worked out the same way as an extra item — see the NS item rate analysis guide.
Test check entries
The supervising officer test-checks a proportion of the recorded measurements. A test check entry records which item was checked, on what date, what quantity and value were checked, that quantity as a percentage of the item's total value, the result, and who checked it.
The percentage is the part people leave blank, and it is the part that gets asked about. A test check statement showing dates and signatures but no percentages does not demonstrate that the prescribed proportion was actually checked.
Draft, locked, and why immutability matters
A paper MB was corrected by scoring out and initialling. A computerized MB has a cleaner rule: it is editable while it is a draft, and immutable once locked.
The sensible locking point is not when the MB is "finished" — it is when the bill built from it becomes final. Up to that moment the abstract, the bill and the memorandum are all still being reconciled against each other, and locking the MB early just forces the reconciliation to happen somewhere less traceable. Locking the MB, the bill and the memorandum together, in one step, is what makes the three consistent by construction.
After locking, a correction is a fresh entry in the next MB, not an edit to the old one. That is the same discipline as a bound book — it is simply enforced instead of trusted.
From MB to running account bill
The MB produces, per agreement item, a quantity measured up to date. Subtracting the quantity billed up to the previous bill gives the quantity for this bill; multiplying by the agreement rate (or the part rate, for rows in a part-rate group) gives the value. That is the abstract.
The abstract then becomes Part I of the running account bill, and the financial adjustments — GST, advances, recoveries, withheld amounts — sit on top of it in the memorandum of payments. That structure is covered in the CPWD Form 26 guide.