---
title: "Preliminary estimate: six-storey office, 3000 m²"
subject: "Estimating and Costing"
chapter: 3
key: "semester_7/estimating_and_costing:prelim-est-six-storey-3000"
source: https://www.bctengineer.com/q/semester_7/estimating_and_costing/prelim-est-six-storey-3000
site: BCT Engineering
---

# Preliminary estimate: six-storey office, 3000 m²

Estimating and Costing · Chapter 3: Types of Estimate

- Asked in: 2076 Chaitra, 4 marks
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/estimating_and_costing/prelim-est-six-storey-3000
- Whole chapter: https://www.bctengineer.com/md/semester_7/estimating_and_costing/chapter-3

## Question

Prepare a preliminary estimate of a six storied framed structure office building having a total carpet area 3000.00 m².
(i) Area for circulation is 20% of plinth area.
(ii) Area for wall and column is 10% of plinth area.
(iii) Prevailing plinth area rate per m² is Rs. 25000.00.
(iv) Extra cost for other services 25% of the cost of building.

## Short answer

Plinth area = 4,285.71 m². Building cost at Rs25,000/m² = Rs107,142,857.14. Adding 25% for other services gives total Rs133,928,571.43.

## Answer

#### Plinth area
$$
\text{Plinth area} = \frac{3000}{1 - 0.20 - 0.10} = \frac{3000}{0.70} = 4,285.71\ \text{m}^2
$$
(total over the six floors; 714.29 m² per floor.)

#### Estimate
| Item | Basis | Amount (Rs) |
|---|---|---|
| Cost of building | 4,285.71 x 25,000 | 107,142,857.14 |
| Other services | 25% of the building cost | 26,785,714.29 |
| **Total** | | **133,928,571.43** |

**Answer: Total estimated cost = Rs 133,928,571.43 (about Rs 13.39 crore).** No contingency is given in the question; if required it is added on this total.

## Check yourself

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

1. Circulation 20%, wall and column 10%. Plinth area:
   A. 4,285.71 m2
   B. 3,000 m2
   C. 3,900 m2
   D. 2,100 m2
   Answer: A. 3000/0.70 = 4,285.71 m2. (Key point: Plinth area)

2. How is the 25% for other services applied?
   A. On the carpet area
   B. On the building cost
   C. On the plinth area
   D. On contingency
   Answer: B. Total = 1.25 x 107,142,857.14. (Key point: Other services)

3. No contingency is given. What does the answer say?
   A. It must be 50%
   B. It is already included
   C. It can be added on the total if required
   D. It replaces other services
   Answer: C. The total is Rs 133,928,571.43. (Key point: Contingency)

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