Test: Estimation and Costing - Civil Engineering (CE) MCQ

The cost of a structure in the cubical contents method is determined by the multiplication of total cubic contents with the local cubic rate. Therefore, the cost of the building is calculated by multiplying the volume of buildings with the rate per unit volume.

As per IS 3861-1966, the areas which should be included while calculating the plinth area of a building are porches of non-cantilever type, area of barsati at terrace level, area of walls at floor level, etc. However, the area of lofts should not be included.

There are various methods used for preparing approximate estimates. These are the plinth area method, unit base method and cubical contents method. An approximate estimate is needed for studying various aspects of the work of the project.

While fixing rate per unit of an item, the quantity of materials and labour needed for one unit of an item are strictly per the Standard Data Book. However, the rates of labour and materials are obtained from the current standard scheduled of rates.

Estimating is the process of calculating the various quantities and their cost in the building construction. It is needed for controlling the expenditure during the execution of the work.

For the preparation of approximate estimates, cubical contents method is more accurate than the unit base method and plinth area method. Cubical contents method is usually used for multi-storeyed buildings.

In the plinth area method, the cost of construction is computed by the multiplication of plinth area and plinth area rate. This area is calculated by multiplying the length and the breadth.

In the case of works that require some special types of equipment, an amount of 1-2 percent of the estimated cost is given. While preparing a detailed estimate, it is also important to select a suitable site of work to reduce damage during the loading and unloading of materials.

The preparation of a detailed estimate comprises of working out quantities of different items of work and then determining the cost of each item. The process of working out the cost per unit of each item is known as data.

For preparing an estimate, data such as drawings, detailed specifications, rates, etc. is required. The drawings needed to prepare the estimate include plans, sections, elevations, etc.