Estimation and Costing (General Engineering) (SSC JE)

Measurement of work–

Earth filling in trenches–
• The unit of measurement for the item of work earth filling in foundation trenches is cubic meter.
• After laying foundation concrete and brick masonry, the remaining trench is filled back with earth upto ground level.

Rental method of valuation–
In this method, the income by way of rent is found out by deduction of all outgoing of the property this method is applicable only when the rent is known or probable rent is determined by enquiries.

Market value–Market value is the price that is currently offered for an asset in the market place.

Book value–The value of an asset based on the asset's initial cost adjusted for any related depreciation, amortization or impairment costs.

Rental method of valuation–
• In this method, the net income by way of rent is found out by deducting all outgoing from the gross rent.
• A suitable rate of interest as prevailing in the market is assumed and year's purchase is calculated.

Indirect expenses–These are general costs and are incurred for the benefit of a number of cost units, process or departments. These cost cannot be easily and conveniently identified with a unit of product or other cost object.

• Depreciation of machinery, insurance, lighting power, rent, managerial salaries, materials used in repairs etc.
• Depreciation of machine of stitching a pair of trousers cannot be known and thus it is an indirect expenses.

Sinking fund–Sinking fund represents the amount of money which required for reconstruction of a structure after completion of its design life.
• The sinking fund is always taken as 90% of the total cost of project.
• 10% value is considered in the form of scrap value.
Total recovery factor–The capital recovery factor is a ratio used to calculate the present value of an annuity.

• Brickwork is usually measured in cum.
• IS : 1200 (part xii)-1976, Prescribes method of measurement of plastering and pointing.
• Dimensions shall be measured to the nearest 0.01 m and areas to be worked out to the nearest 0.01 m² , to be measured separately according to thickness and material.
• No deduction to be made for opening below 0.5 m² , when such opening exceed 0.5 m² but do not exceed 3m² , deduction shall be made as below–
• When both face walls are plastered, deduction shall be made for one face only.
• When only one face is plastered, full deduction shall be made when areas of opening exceed 3m² , each, deduction shall be made for opening on each face.

For making spiral staircase, ideal material is steel.
• IS : 1634, gives details about wooden stair.

Estimation–An estimate is calculation of the quantities of various item of work and the expenses likely to be incurred theorem.
• The total of these probable expenses to be measured on the work is known as estimated cost of the work.