Estimating part 2
- 1. ESTIMATING & COSTING ARUN RAVI.K.R Instructor, Draughtsman (Civil) Part -2
- 2. Different Types of Sanctions01 LEARNING OBJECTIVES Different Types of Estimates02
- 3. Estimate Sanction Before the execution Three Sanctions are Required Administrative Sanction Financial Sanction (Expenditure sanction) Technical sanction
- 4. Administrative Sanction (A.S) For any project an approval or sanction of the competent authority of the department is necessary at the first instance with respect of the cost and work. (Sanction from Govt.) Administrative approval denotes to formal acceptance of the proposal. After A.S, the engineering department take up the work and prepares detailed design, plans and estimates and then executes the work.
- 5. Financial Sanction (Expenditure sanction) Financial sanction means allotment of fund or money for a project from the finance department of Government
- 6. Technical Sanction (T.S) The sanction of the detailed estimates, design calculation, quantities of works, rates and cost of the work by the competent authority of the engineering department is known as Technical Sanction.
- 8. Preliminary or approximate or abstract estimate This type of estimate is required for preliminary studies of a project, to decide the financial position and policy for administrative sanction by the competent administrative authority. The approximate estimate is prepared with the practical knowledge and cost of the similar works. This is also accompanied with a site plan or layout plan. A percentage of about 5% to 10% is added as contingencies.
- 9. Plinth area estimate (P.A. estimate) This is prepared on the basis of plinth area of building, the rate being deducted from the cost of similar building having similar specification, heights and construction, in the locality. Plinth area estimate is calculated by finding the plinth area of the building and multiplying by the plinth area rate.
- 10. Cubic rate estimate This is prepared on the basis of the cubical contents of the building. The cube rate being deducted from the cost of the similar building having similar specifications and construction, in the locality. This is calculated by finding the cubical content of the building (length x breadth x height) and multiplied it by the cube rate. Cube rate estimate is most accurate than to the plinth area estimate
- 11. Approximate quantity method In this method approximate total length of work is found in running metre and this total length multiplied by the rate per running metre of wall gives a fairly accurate cost. For this method the plan or line plan of the structure should be available.
- 12. Detailed estimate Detailed estimate is an accurate estimate consists of the quantities of each item of works, and working the cost. The dimensions, (length, breadth and height) of each item are taken out correctly from drawing and quantities of each item are calculated. The detailed estimate is prepared in two stages. 1) Details of measurement and calculation of quantities 2) Abstract of estimate cost
- 13. 1) Details of measurement and calculation of quantities The details of measurement of each item of work are taken out correctly from plan and drawings and quantities under each item are computed or calculated in a tabular form named as Details of Measurement Form (Table 1).
- 14. 2) Abstract of estimate cost The cost of each item of work is calculated in a tabular form from the quantities already computed and total cost is worked out in abstract of estimate form (Table 2). The rates of different items of work are taken as per schedule of rates
- 15. Detailed Estimate Abstract estimate
- 16. Revised estimate Revised Estimate is detailed estimate and is prepared under any one of the following circumstances. I. When the original sanctioned estimate is exceeds more than 5%. II. When the expenditure on a work exceeds of administrative sanction by more than 10% III. When there are material deviation from the original proposal, even though the cost may be met from the sanctioned amount. The revised estimate should be accompanied by a comparative statement showing the variations of each item of works
- 17. Supplementary estimate Supplementary estimate is a detailed estimate and is prepared when additional works are required to supplement the original works, or when further developments is required during the progress of work. This is a fresh detailed estimate of the additional works in addition to the original estimate.
- 18. Supplementary and revised estimate When a work is partially abandoned and the remaining work is less than 95% of the original sanctioned estimate. Or when there are material deviations and changes in the design which may cause excess or saving in the estimate, A supplementary and Revised Estimate is then prepared and fresh technical sanction of the competent authority is obtained.
- 19. Annual repair or annual maintenance estimate (A.R. or A.M. Estimate): This estimate is a detailed estimate and is prepared to maintain the structure or work in proper order and safe condition. For building: Includes white washing, colour washing, painting, minor repairs etc. For road works: Tarring patch repairing, renewals, repairs of bridges and culvert, etc.
- 20. Extension and improvement estimate When some changes and extensions are required to be made in the old work, the cost of which cannot be met by the annual repair/maintenance estimate, a detailed estimate is prepared for such work which is called as extension and improvement estimate.
- 21. ARUN RAVI.K.R Instructor, Draughtsman (Civil) arunravikr@gmail.com 9447622946