An estimate is the anticipated or probable cost of work and is usually prepared before the construction is taken up. Before undertaking the construction of a project it is necessary to know its probable cost which is worked out by estimating. An estimate is a computation or calculation of the quantities required and expenditure likely to be incurred in the construction of a work. The actual cost is known only after the completion of the work from the account of the completed work.If the estimate is prepared carefully and correctly, there will not be much difference between the estimated cost and the actual cost.
Preliminary estimate –
The preliminary estimate is required for preliminary studies of various aspects of a work or project, to decide the financial crisis position and policy for administrative sanction by the competent administrative authority.
In case of commercial projects as irrigation project residential building project and similar projects which earn revenue income, the probable income may be worked out and from the preliminary estimate, the approximate cost may be known and Then it may be seen whether the investment in the project is justified or not. A percentage of about 5% is 10% is added as contingencies.
Plinth area estimate –
This estimate is an approximate estimate it is consists of workout the plinth area of a building which is multiplied by a building that is multiplied by the plinth area rate to get an estimate for that building. The plinth area should be calculated for the covered area by taking external dimensions of the building at the floor level. Courtyard and other open areas should not be included in the plinth areas.
Cube rate estimate –
This estimate is also an approximate estimate it is the workout of the basis cubical content of the proposed building to be constructed and then applying to at the rate per cubic content. The length and breadth should be taken from the floor level to the top of the roof.
Approximate estimate –
In this method, the approximate total length of walls is found in the running meter and this total length multiple by the rate per running meter of the wall gives a fairly accurate cost.
To find the running meter rate for the foundation the approximate quantities of items such as excavation, foundation brickwork up to plinth, and dampproof course are calculated per running meter is determined.
Detailed estimate –
A detailed estimate is an accurate estimate and consists of working out the quantities of each item of work and working the height of each item are calculated the detailed estimate is prepared in two estimates.
- Detailed measure and calculation of quantities.
- Abstract of estimated cost.
Revised estimate –
A revised estimate is a detailed estimate and is required to be prepared under any following Circumstances
- When the original sanctioned estimate exceeds or likely to exceed by more than 5%.
- When the expenditure on work exceeds s or likely to exceed the amount of administrative sanction by more than 10%.
- When there is a material deviation from the original proposal even though the cost may be met from the sanctioned amount.
Supplementary estimate –
The supplementary estimate is a detailed estimate and is prepared when additional works are required to supplement the original works, or when further development is required during the process of work. This is a freshly detailed estimate of the additional works in addition to the original estimate.
Annual repair maintenance estimate –
An annual repair or annual maintenance estimate is a detailed estimate and is prepared to maintain the structure or work in proper order and safe condition. For building this includes whitewashing, color washing, painting, minor repairs, etc. further, there may be a special repair estimate, monsoon damage repair estimate, etc.