Estimation and Costing - Contracts

1. Contract Administration
&
Quantity Surveying

2. Course Outline
 Contract Administration & Quantity Surveying
 Academic Year 2005
Semester I
 Objective: to learn how to estimate, quantity survey,
analysis rate, to write specifications, and to prepare
contract document with their importance. And
understand basic principles of contract in civil
engineering.
 Chapter I: Estimating in Civil Engineering
Introduction
Data for estimate
Types of estimate

3.  Chapter II: Specifications
Introduction
Importance of specification in civil engineering
Types of specification
Specification writing
 Chapter III: Quantity Survey
Introduction
Measurement of Civil Works
Basic Principles in Taking Off
Takeoff sheet preparation for building structure.
Chapter IV: PROJECT COST ESTIMATION AND
VALUATION
Introduction
Purposes of Cost Estimation
Types of Costing or Estimation
Rate Analysis.

4.  Chapter V: Basic Principles of procurement & Contract
in Civil Engineering
Introduction to Procurement
Basic terms
Principles of Contract Law
Types of Construction Contract
Contract Documents
Contract Management
Contracting [objective, essentials, scope, types, and conditions of
contract]
Agreement
Claims in civil engineering.
References:
 Estimating,costing,specification,and valuation in civil engineering ,by
M.Chakraborti
 Civil engineering estimating and costing, by V.N. VAZRANI
 Quantity Surveying Practice, by Lvor Seeley

5. Evaluation:
 40% = Mini Project
 10-20% = Quiz and attendance
 50-40% = Final Exam
Instructor: Biniam T.
 [May subjected to change]

6. Chapter I
Estimating in Civil Engineering

7. Scope of civil engineering works
 Civil engineering is a professional engineering
discipline that deals with the construction and
design of public and private sector works such as
bridges, roads, dams and buildings.
 General civil engineers work closely with surveyors
and specialized civil engineers to fit and serve fixed
projects within their given site, community and
terrain by designing grading, drainage, pavement,
water supply, sewer service, electric and
communications supply and land (real property)
divisions.

8. Before taking up any work for its execution, the client
should have a thorough knowledge about the probable
cost required for the complete execution of the
proposed work
 IMPORTANCE OF ESTIMATION
 To ascertain the necessary amount of money
required by the owner to complete the proposed
project
 To ascertain quantities of materials required so as to
program their timely procurement.
 To calculate the number of different categories
of worker that are to be employed to complete the
work within the schedule time of completion

9. cont…
 To asses the requirements of tools, plants, and
equipments required to complete the work according
to the program.
 To fix up the completion period from the volume
of works involved in the project
 To draw up a construction schedule and program and
to arrange the funds required according to the
program.
 To justify the investment from benefit-cost ratio.

10. BEST ESTIMATES
 The accuracy of an estimate depends on a careful
study of:

 The various dimensions of the drawings;
 The method of estimating;

 Consideration of rates;

 Probable expenses which may be required for various
unforeseen works and labors; and

 Quantities of tolerance for wastage.
 skill and experience of the estimator

11.  since an estimate is never the actual cost of
construction of the work ,All expenses for all
probabilities can be known when the construction is
completed.
 In general, all estimates are approximates in nature
and the difference between the estimated cost and the
actual cost is a vital issue, which must be minimum.
Hence, best estimate is that, in which, during the
actual execution of work, there are:
 Minimum deviations in the estimated quantities
of different items of work;
 Minimum or no extra and additional items;

12.  Minimum deviation in cost
 No or minimum provision of lump-sum items.
TYPES OF ESTIMATE
1 Approximate estimate;
2 Detailed or accurate estimate; and
3 supplementary estimate.

13. .
1 APPROXIMATE/PRELIMINARY /ESTIMATE
objective is to find out an approximate cost in a
short time which is used to consider the financial
aspect of the client.
During preparation of this estimate:
 only line sketch of the project is used(no detailed
surveying, design, drawings )
Rates are determined either from practical
knowledge or from records for similar works

14. Services like sanitary, water supply, electrification,
boundary walls, roads, cost of land etc. are made
separately.
Provision of contingency of 5-10% is added to
approximate safe total project cost.
The estimate report [with a brief statement of basis of
estimate, rates, etc.] with a line plan, site or layout
plan, soil test results [if any] should be provided.
up-to-date records for rates and matured practical
knowdelage are essential.

15. BENEFITS OF APPROXIMATE ESTIMATE
 To investigate feasibility
 To save time and money:
To avoid project rejection due to an unexpected
difference between the amount of the detailed estimate
and the availability of fund in advance.
 To investigate benefits and comparison
of cost with utility: Adjustment of planning:
to decide or reject the preparation of detailed
estimate of the project, respectively


16. Cont…
 Adjustment of planning:
to prepare a number of alternatives for the original
work with sketch
To obtained administrative approval for
detailed investigation
For insurance and tax schedule:

17. METHOD OF APPROXIMATE
ESTIMATES FOR BUILDINGS
1 ) Plinth Area or Square Meter Method
   
buildings
d
constructe
recently
similar
for
locality
of
rate
area
Plinth
*
building
the
of
area
Plinth
cost
Estimated 
The following are factors control
plinth area rate
• The type of building, the quality of material,
type of flooring, quality of wall finishing, etc;

• The cost of currently built buildings in
the locality;

• Shape of building;

18.  Economic design of the
building
 Arrangement of rooms, circulation
area, and provisions made for
sanitary blocks; and

 Location of building.
 2 Cubic Rate or Cubic Meter Method
 Is more accurate [in general] than plinth area
method, because the cost of a building depends
more logically on the volume of the building.

19. 












locality
that
in
buildings
d
constructe
recently
similar
of
volume
cubic
per
Rate
*
building
proposed
the
of
content
cubic
or
Volume
cost
Estimated
Height
*
Breadth
*
Length
building
a
of
volume
Total 
Length * Breadth is taken conveniently the plinth area of a building
In the determination of the rate per cubic meter, those
factors which govern plinth area method govern a cubic
method too.
Provisions like sanitary, water supply, drainage,
electric installations, etc. should be made on the
basis of percentage cost of the building estimate

20. The following percentages of the building
estimate costs are adopted:
 4-5% for sanitary;
 4-5% for water supply;
 9% for electrification;
`
 3% for electric funs, lights.

21. 2 A DETAILED /ACCURATE/ ESTIMATE
 is prepared to know an exact cost of the project
 the correct quantities of various types of items of work
are calculated with the help of detailed drawings,
specification, and designs.
 In preparing detailed estimates one may follow the
following processes one after another:
 Preparation of drawings
Includes floor plans, elevations, and sections

22.  Preparation of specifications
To determine detailed descriptions of all workmanship
and materials which are required for the complete
execution of the project.

 Preparation of bill of quantities/quantity survey
To provide a complete list of quantities necessary
for the completion of the project total cost multiplying by
the rates per units for all items and summing.
 Analysis of rates
To determine the current per unit of an item at the
locality.


23. 3 SUPPLEMENTARY ESTIMATE
 While work is in progress, any change is ordered in the
original proposal due to material deviation of a
structural nature, for the betterment and development
of the project.
 For such changes, an estimate for the additional items
of work is prepared [with same accuracy of detailed
estimate] and amount is worked out, for which the
sanction is obtained, or required. Preparation of such
types of estimate is known as a supplementary
estimate.