---
title: "Principle of units; data for detailed estimate"
subject: "Estimating and Costing"
chapter: 1
key: "semester_7/estimating_and_costing:principle-units-data-required"
source: https://www.bctengineer.com/q/semester_7/estimating_and_costing/principle-units-data-required
site: BCT Engineering
---

# Principle of units; data for detailed estimate

Estimating and Costing · Chapter 1: Introduction

- Asked in: 2076 Chaitra, 3 marks
- Video: [Part 19 ! Estimating and Costing ! Detailed estimate ! Rough cost estimate ! Types of estimate ! SSC](https://www.youtube.com/watch?v=0vU2E4GznJk) — NARAYANA COACHING CLASSES
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/estimating_and_costing/principle-units-data-required
- Whole chapter: https://www.bctengineer.com/md/semester_7/estimating_and_costing/chapter-1

## Question

List out the principle of units of measurement. Explain the data required for preparing a detailed estimate.

## Short answer

Units follow geometry: length in m, area in m², volume in m³, countable items in numbers, weight in kg/tonne, and lump sum for unmeasurable items. Measurement is net finished quantity with deductions, to 0.01 m, m² or m³. Data required include drawings, specifications, rates, site data, quantities, and provisions.

## Answer

#### Principles of units of measurement
Every item of work is measured and paid in one unit, chosen by the nature of the work, as per IS 1200 and the Nepal standard practice:
1. Work in **one dimension** (length governs, section fixed) is measured in running metre (m): e.g. cornice, skirting, pipes, railing.
2. Work in **two dimensions** (thickness fixed) is measured in square metre (m²): plastering, flooring, painting, formwork, half-brick wall.
3. Work in **three dimensions** is measured in cubic metre (m³): excavation, concrete, brickwork, masonry.
4. Small, countable items are measured in **numbers** (nos.): doors, fixtures, W.C.
5. Items sold by weight are measured in **kg, quintal or tonne**: reinforcement, structural steel.
6. Items that cannot be measured are paid as **lump sum (L.S.)**.
7. Measurement is of the **net finished quantity** in place; deductions are made for openings and voids as per the rules. Dimensions are measured to the nearest 0.01 m, areas are worked out to the nearest 0.01 m² and volumes to the nearest 0.01 m³. The unit of measurement is the same as the unit of payment.
8. The description includes all work, materials and incidental labour necessary to complete that unit.

#### Data required for a detailed estimate
1. Complete drawings (plans, sections, elevations, details).
2. Specifications of materials and workmanship.
3. Rates: District Rate and DUDBC norms for rate analysis.
4. Site data: soil, lead, water, labour availability.
5. Item-wise quantity calculation, then abstract of cost.
6. Contingency, taxes and overhead provisions.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which unit is used for plastering, flooring and painting?
   A. Running metre
   B. Square metre (m²)
   C. Cubic metre
   D. Kilogram
   Answer: B. Two-dimensional work with fixed thickness is measured in m². (Key point: Unit by dimension)

2. Which items are measured in cubic metre?
   A. Skirting and cornice
   B. Doors and W.C.
   C. Excavation, concrete and brickwork
   D. Reinforcement
   Answer: C. Three-dimensional work goes in m³. (Key point: Volume work)

3. What quantity is measured?
   A. Gross quantity including wastage
   B. Only the quantity ordered
   C. An estimated lump value
   D. Net finished quantity in place, with deductions for openings and voids
   Answer: D. Net finished work in place is measured; the unit of measurement equals the unit of payment. (Key point: Net quantity)

## Related in Estimating and Costing

- [Data required for detailed estimate](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Adata-for-detailed-estimate) — Estimating and Costing, chapter 1
- [Preparing a detailed estimate of a building](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Aprepare-detailed-estimate-building) — Estimating and Costing, chapter 2, asked 4×
- [Tasks in preparing building project estimate](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Aworks-considered-building-project-estimate) — Estimating and Costing, chapter 5, asked 2×
- [Measurement and units: pointing, steel](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Ameasure-pointing-steel-units) — Estimating and Costing, chapter 1
- [Units of measurement and payment, civil and sanitary](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Aunits-civil-sanitary-works) — Estimating and Costing, chapter 1
- [Estimating, purpose and data required](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Aestimating-purpose-data-required) — Estimating and Costing, chapter 1, asked 6×

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