--- title: "Preliminary estimate: 4-storied office, 2000 m²" subject: "Estimating and Costing" chapter: 3 key: "semester_7/estimating_and_costing:prelim-est-office-2000-d" source: https://www.bctengineer.com/q/semester_7/estimating_and_costing/prelim-est-office-2000-d site: BCT Engineering --- # Preliminary estimate: 4-storied office, 2000 m² Estimating and Costing · Chapter 3: Types of Estimate - Asked in: 2081 Baisakh, 5 marks; 2066 Bhadra (old course), 7 marks (asked 2 times) - Video: [Preliminary Estimate Numerical | Plinth Area Method | TYPE - 1 (QSC) - [HINDI]](https://www.youtube.com/watch?v=ngjaqk1YtW4) — Learn Civil Tech & Tricks - 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-office-2000-d - Whole chapter: https://www.bctengineer.com/md/semester_7/estimating_and_costing/chapter-3 ## Question Prepare a preliminary estimate of a 4 storied office building having a total carpet area of 2000 m² for obtaining the administrative approval of the ministry. Given the following data: - 30% built up area will be taken up by corridors, verandah, toilets, staircase etc. - 10% of built-up area will be occupied by walls - Plinth area rate is Rs. 15000/m² - Extra for special architecture treatment 1.5% of the building cost - Extra for electric installation 8% of the building cost - Extra for other services 5% of the building cost - Contingencies 5% of the total building cost - Supervision charge 5% of the total building cost ## Short answer Plinth area = 2000/(1−0.3−0.1) = 3333.33 m². Building cost = 3333.33 × 15000 = Rs 50,000,000; adding architectural (1.5%), electric (8%), other services (5%) gives total building cost Rs 57,250,000; after 5% contingency and 5% supervision, final estimate = Rs 62,975,000. ## Answer #### Method Plinth (built-up) area is found from the carpet area, as the carpet area is what remains after the circulation (30%) and wall (10%) areas are removed: $$ \text{Plinth area} = \frac{2000}{1 - 0.30 - 0.10} = \frac{2000}{0.60} = 3333.33\ \text{m}^2 $$ This is the total plinth area of all 4 floors (833.33 m² per floor). #### Calculation | Item | Basis | Amount (Rs) | |---|---|---| | Building cost | 3333.33 m² x 15,000 | 50,000,000 | | Special architectural treatment | 1.5% of 50,000,000 | 750,000 | | Electric installation | 8% | 4,000,000 | | Other services | 5% | 2,500,000 | | **Total building cost** | | **57,250,000** | | Contingencies | 5% of 57,250,000 | 2,862,500 | | Supervision charge | 5% of 57,250,000 | 2,862,500 | | **Total estimated cost** | | **62,975,000** | **Answer: Plinth area = 3333.33 m²; total estimated cost = Rs 62,975,000 (about Rs 6.30 crore).** Contingency and supervision are taken on the total building cost (Rs 57,250,000) as given in the question. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. Carpet 2000 m2, circulation 30%, walls 10%. What is the plinth area? A. 1,428.57 m2 B. 3,333.33 m2 C. 2,800 m2 D. 1,200 m2 Answer: B. 2000/0.60 = 3,333.33 m2. (Key point: Plinth area) 2. What is the building cost at Rs 15,000/m2? A. Rs 30,000,000 B. Rs 5,000,000 C. Rs 50,000,000 D. Rs 57,250,000 Answer: C. 3,333.33 x 15,000 = 50,000,000. (Key point: Building cost) 3. Extras are 1.5% + 8% + 5%. What is the total building cost? A. Rs 50,750,000 B. Rs 62,975,000 C. Rs 54,000,000 D. Rs 57,250,000 Answer: D. 14.5% of 50,000,000 = 7,250,000. (Key point: Total building cost) 4. On what is 5% contingency charged? A. The total building cost (Rs 57,250,000) B. The plinth area C. Rs 50,000,000 only D. The total estimated cost Answer: A. 5% = 2,862,500; with supervision of 2,862,500 the total is Rs 62,975,000. 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