Page 287 - Electrician - TT (Volume 2)

ELECTRICIAN - CITS

MODULE 17 : Estimation and Costing

LESSON 104&105 : Concept - Principle of plan estimation

cost preparation

Objectives

At the end of this lesson you shall be able to:
• state the concept and principle of plan estimation
• calculate estimate and cost preparation of wiring layout
• describe safety regulation - 2010 multi storey building.

Principles of estimating and schedule of rates

Estimate: The method of calculating the cost of material and labour is called estimate.
The idea of an estimate is to have the cost of work for arranging the funds and explore the market for the
availability of materials.

The estimate should have additional funds or any contingencies required during the construction and generally an
additional amount equivalent to 5% of the total cost is added to the estimate as contingencies.
For preparing an estimate, the following are necessary (Fig 1)

Drawing: The necessary drawings of the building with dimension are required for the execution of work and also
for estimation. For electrical installation, the layout of the wiring should be shown on a separate drawing along
with the positions of the points etc.

Fig 1

Specification of materials: Specification gives the details of materials, brand name, grade, quality, rating of
voltage, current, quality of certification like ISO or BIS etc. It helps both the wireman and the consumer to select
the material according to commercial practice, cost and requirements.
Schedule of rates and records
Specifications, rates and records are need for preparing and checking the estimates. They are also useful for
materials procurement.

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CITS : Power - Electrician & Wireman - Lesson 104&105