DIFFERENT TYPE OF ESTIMATE
What is an estimate? Estimate is the probable cost of a building or a project. It is a calculation of the quantities of various items of work, and the expenses likely to be incurred on them. Estimate is a tool for planning and controlling the construction activity of any project with respect to quality, time and finance. Different types of estimate: 1. 2. 3. 4. 5. 6.
Preliminary or rough cost estimate. Detailed estimate. Revised estimate. Supplementary estimate. Special repairs estimate. Annual repair and maintenance estimate.
Purpose of different estimates: PRELIMINARY OR ROUGH COST ESTIMATE:
This estimate as the very name implies, is a very rough estimate and is based on the requirement of the client. The client gives his requirement to the Civil Engineer and he in turn prepares the rough cost estimate. The client’s requirement will generally be the number of rooms he wants or the number of person he wants to be accommodated in the building. For example if a Doctor constructs a nursing home, he will give his requirement in the number of in-patient room he wants, the number of consultation room he wants, the number of rooms for housing the lab, etc., based on this the estimator works out roughly how much area of building is to be constructed and the preliminary estimate is worked out on that. Similarly a person constructing a school will give his requirement in the form of the number of class rooms, the number of lab, area for physical education section etc., A person who wants to construct a Office building will give the number of Officers and the number of staff to be housed in the Office and also the requirement of canteen, rest room etc., Based on the clients requirements the estimator works out the area of building to be constructed and based on it roughly works out the cost that will be incurred in constructing that building. This cost is meant for planning and scheduling the available budget. If the estimated cost does not fall within the budget of he client, the area can be reduced and the cost brought within the available budget. In Government Department this estimate is prepared for obtaining the Administrative Administrative Approval and Expenditure Expenditure Sanction. The client Department releases releases a budget to the Department undertaking the construction based on the amount of the estimate.
DETAILED ESTIMATE:
This estimate is prepared based on the available Architectural and structural drawings. In this estimate the quantities of individual items like earth work excavation, plain cement concrete, Reinforced cement concrete etc., are worked out. The individual quantities are multiplied by the prevailing rates and the correct cost of the work is arrived at. In Government works Delhi Schedule of rates duly enhanced with cost index are used. This individual quantities of items are basically prepared for calling of tenders. For the worked out quantities the contractors will be quoting their rates, and the person who quotes the lowest rate will be awarded the work. In Government Department the Technical sanction is accorded based on this estimate. REVISED ESTIMATE:
If during the execution of work, the quantities exceeds or if some of the items are deviated or substituted, or if the scope of work is changed, a revised estimate is prepared for getting the sanction of competent authorities. For example during execution of work, the Architect decides to have alco panel façade instead of ordinary elevation, the cost of work will go up. In such cases revised estimate is prepared SUPPLEMENTARY ESTIMATE:
Supplementary estimate is prepared whenever there is a considerable change in the scope of work. For example a hospital project is under way and the client decides to have one more block for X-ray then the project cost will go up considerably. In this case the supplementary estimate will be prepared and added to the main estimate. SPECIAL REPAIR ESTIMATE:
Suppose in an existing building due to passage of time the plastering starts falling and there is spalling of concrete. Then the building requires extensive repairs and an estimate is prepared for this. This type of estimate is known as special repair estimate. ANNUA L REPA IR AND MA INTENANCE ESTIMA TE:
In buildings some of the items of work needs to be executed every year. For example the white washing and painting works are to be done every year. And also some of the items which undergo constant wear and tear like taps etc., also needs replacement. For such of those items an estimate is prepared and the annual works are undertaken and this type of estimate is known as annual repair and maintenance estimate.
