It is a probable cost required for carrying out any proposed construction.

Estimating: It is the process of calculating the quantities and the costs of various items of work required for succesfull completion of project.

Purposed of estimating:

1. To know the approzimate cost of the proposed work.

2. To know the quantity of various mateiral to be required.

3. To know the number of labours of various category to be required for entire execution.

4. To know the tools and equipments to be needed for the executions.

5. To get administrative approval and technical sanctions

(i) Approximate/Preliminary/Rough estimate: This is an estimate prepared to find out an approximate cost of the project in a short period of time, without taking out atual quantities.

It gives us rough idea about the finance required for proposed constructions. It is to be prepared for getting administartion approval from the competant authority of the department.

Methods for preparing Approximate estimate:

(i) Plinth area of sq.m/${m_2}$ method

(ii) Cubic content or $m_3$ method

(iii) Approximate quantity with bill method

(iv) Cost comparison method

(v) CBRI method

(vi)Service unit method

(vii) Typical bay method