Unit-1 , Estimate ,types of estimate,civil engineering 2021 notes

 Estimate:-

It is the process which guide us to determine the cost, quantity, tools, plants and labours which are needed to complete the work for project with in time of completion.
The actual cost of a work is known at the completion of the work. Account of all expenditure is maintained day-to-day during the execution of work in the account section and at the end of the completion of the work when the account is complete, the actual cost is known. The actual cost should not be differ much from the estimated cost worked out at the beginning.

Estimating material:-

  • From the estimate of a work it is possible to determine what materials ( in what quantity ) will be required for the work.

Estimate labour:-

The number and kind of workers of different categories who will have to be employed to complete the work in the specified time can be found out from the estimate.

Estimate plant:-

An estimate will help in determining the amount and kind of equipment needed to complete the work.

Estimate the time:-

The estimate of a work and past experience enable one to estimate quite closely the length of time required to complete of work or the work as a whole.

Types of estimate:-


1. Approximate estimate:-

it is done in order to find out an approximate cost in every short time before starting the project. The estimate is made before selecting the final specification and design of the project. It is rough estimate.

2. Detailed estimate:-

This is the accurate method of estimating in which the entire building work is subdivided into individual items of work.
The quantities of each item of work are calculated from the complete set of drawings ( plan, elevation, section etc. )

It is the best and most reliable from of estimate.

There is it to method to calculate detailed estimate.

a. Unit quantity method:-

  • The work is divided into ad many operations or items as are required.
  • A unit of measurement is decided.
  • The total quantity of work under each item is taken out in the proper unit of measurement.
  • The total cost per unit quantity of each item is analysed and worked out.
  • Then the total cost for the item is found by multiplying the cost per unit quantity by the number of units.
  • That the total estimate can easily be corrected.

b. Total quantity method:-

Materials, labours, plant, overheads, profit.
Total quantity of each kind or class of material or labour are found and multiplied by their individual unit cost.
Similarly the cost of plant overhead expense and profit are determined.

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