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Department of Collegiate and Technical Education

Introduction to Estimation (Unit 1)

Course outcome

Estimation & Costing( V Semester)

Civil Engineering

Civil Engineering – 15CE53T

Table of Content

➢ Introduction

➢ Purpose Of Estimation

➢ Types Of Estimates

➢ Deduction & Measurement Rules

➢BOQ, Schedule Of Rates & Lead Statement

➢ Test - MCQ


Introduction

ESTIMATION:

An estimate is the anticipated or probable cost of work and is

usually prepared before the construction is taken up.


Purpose of Estimation

•It gives an idea of the cost of the work, i.e whether the project could

be taken or not.

•To get administration approvals in case of govt projects.

•It gives an idea of time required for the completion of the work.

•It is required to invite the tenders and quotations and to arrange

contract.

•It is also required to control the expenditure during the execution of

work.

•Estimate decides whether the proposed plan matches the funds

available or not.


Data Required For Estimation


DATA Required

DRWAINGS

RATESSPECIFICATIONS

Types Of Estimates


•Preliminary estimate / approximate/ rough estimate

•Plinth area estimate

•Cube rate estimate

•Approximate quantity method estimate

• Detailed estimate / item rate estimate

•Revised estimate

•Supplementary estimate

•Supplementary & revised estimate

•Annual repair and maintenance estimate

❖Preliminary estimate / approximate/ rough

estimate


This is prepared at the beginning of the project, with a little

information available with similar project reference.

❖Plinth area estimate

Plinth area estimate = plinth area x rate

= ( Floor area + wall area) x rate

❖Cube rate estimate


Cube rate estimate = cubical content x rate

= ( L x b x d) x rate.

❖Approximate quantity method estimate

Approximate quantity method estimate = total length of the

wall x rate per meter.

❖Detailed estimate / item rate estimate


It consists of working out each and every items of work and

their cost . it is prepared in two stages.

•Details of measurements and calculation of quantities

•Abstract of estimate form.

❖Details of measurements and calculation of

quantities


The complete work is divided into various items and each

quantity is calculated and entered into format as shown :

❖Abstract of estimate form


The cost of each item of work is calculated from already

computed quantity .. the rates are taken from s r or from rate

analysis.

•3 % to 5% is added for contingencies

( unforeseen expenditures)

•1.5 % to 3% for work charged establishment

❖ Revised estimate


It is done under any one of the following circumstances:

•When the original estimate exceeds or likely to exceed by

more than 5%.

•In case where there is a structural alterations

•When the sanctioned amount is more than the actual

requirement.

• While a work is in progress, if additional works are incurred ,

for such supplementary work sanctioned amount may shortfall

, then there is a need of supplementary estimate

❖ Supplementary estimate

❖ Supplementary and revised estimate


When it is necessary to increase the volume of the work , then

revise estimate may be done for the increased volume of work.

❖Annual repair and maintenance estimate

•It is prepared to maintain the structure or work in safe

condition,

•It includes repair works of buildings, roads, bridges and

culverts.

❖ Units of measurements for different items of works


•For single units – no’s ( eg: doors, windows, truss etc..)

•For linear measurements – running metre (eg: cornice, hand

rail, band concrete)

•For surface measurements involve area – square meters (m2)

(eg: plastering, white washing painting)

•For cubical contents – cubic metre( eg: earth work, cement

concrete, masonry etc

❖ Deduction of openings in different items of work

and measurement as per BIS-2000


Plastering:

Rules for measurements:

•Plastering on roofs, ceilings and walls shall be measured

separately.

•Removing plaster by scraping shall be measured separately in

m2

•Plastering at a height greater than 10 m above ground/datum level

shall be measured separately in stages of 5-m height.

•All plastering shall be measured in square meters unless

otherwise described.

❖ Rules for Deduction


➢No deduction shall be made for openings not exceeding 0.5 m2 each and no

addition shall be made for reveals, jambs, soffits, sills, etc, of these openings

➢Deductions for openings exceeding 0.5 m2 but not exceeding 3 m2 each shall

be made as follows and no addition shall be made for reveals: jambs, soffits,

sills, etc, of these openings:

➢When both faces of wall are plastered with same plaster, deduction shall be

made for one face only

➢When width of door frame is equal to thickness of wall or is projecting

beyond thickness of wall, full deduction for opening shall be made from each

plastered face of the wall.

➢In case of openings of area above 3 m2 each, deduction shall be made for

opening on each face but jambs., soffits and sills shall be

➢ measured.

❖ Bill Of Quantities


A bill of is a document used in tendering in the construction

industry in which materials, parts, labors ( and their cost) are

itemized to complete a given project

❖ Schedule of rates

S r is a list of rates of various items of works. To facilitates the

preparation of estimates.

•It is maintained by p w d in the form of printed book.

•It contains all the rates like, materials, labor wages, transportation

charges etc..

❖ Lead statement


Lead statement: the distance between the source of availability of

material and construction site is known as "lead " and is expected

in km.

Mr. Madhu

Senior Lecturer,

Department of Civil Engineering,

G.P.T Raichur

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