Estimating and costing

ESTIMATING AND
COSTING
PRESENTED BY : AYUSH N. HAJARE
DIPLOMA STUDENT (CIVIL ENGINEERING)
ayushhajare843@gmail.co

CONTENT
• Introduction to estimating and costing
• Importance of estimating
• Purpose of estimating
• Data required for estimating
• Types of estimates
• Rate analysis
• Terms used in rate analysis
• Provision and purposes of different charges
• Terms used in estimates
• Unit of measurement for various construction activities
• Items and measuring units
• Conclusion
ayushhajare843@gmail.co

INTRODUCTION OF ESTIMATING AND
COSTING
• Estimating and costing are closely the same things. The estimate is
defined as the process of calculating the various quantities and the
expected expenditure to be incurred on a particular work or
project. The estimate gives the probable cost of work.
• The primary objective of an estimate is to enable one to know the
probable cost of the work before the completion of the project. If
the estimate is prepared carefully and correctly there will not be
much difference between estimated and actual cost.
ayushhajare843@gmail.com

IMPORTANCE OF ESTIMATING
• The estimate is necessary for fixing the budget for the purposed
project.
• It is necessary to calculating the required quantities of materials
and laborers for the project.
• It is necessary to draw up a work schedule.
• It is necessary to fix up the completion period of the proposed
project.
• It is also helpful to check the works done by contractors during and
after the execution.
• It is required for preparing tenders for the project.
• It is necessary for the valuation of land and building.

PURPOSE OF ESTIMATING
• To estimate the probable cost of the work.
• To find the various types and quantities of material required.
• To find the various categories and quantities of labors required.
• To give an idea of the time required for completion of the work.
• To justify investment from benefit-cost ratio.
• To help in fixation of standard rent and valuation of properties.

DATA REQUIRED FOR ESTIMATING
• Drawing – plans , elevation, sections, etc.
• Specifications
• Rates
• Methods of measurements

• DRAWING
If the drawings are not clear and without complete dimensions the
preparation of estimation become very difficult. So, it is very essential
before preparing an estimate.
• SPECIFICATIONS
a) General Specifications: This gives the nature, quality, class and work
and materials in general terms to be used in various parts of wok. It
helps no form a general idea of building.
b) b) Detailed Specifications: These gives the detailed description of the
various items of work laying down the Quantities and qualities of
materials, their proportions, the method of preparation workmanship
and execution of work.

• RATES
For preparing the estimate the unit rates of each item of work are
required.
1. for arriving at the unit rates of each item.
2. The rates of various materials to be used in the construction.
3. The cost of transport materials.
4. The wages of labor, skilled or unskilled of masons, carpenters,
Amador, etc.

TYPES OF ESTIMATES
• The construction cost estimates can be prepared either in a
detailed manner by taking into consideration item by item or
can be calculated approximately without going much into the
details. Based on these criteria, there are mainly 8 cost
estimates followed in construction:
 Approximate or Preliminary estimate
Plinth area estimate
Cube rate estimate
Detailed estimate
Revised estimate
Supplementary estimate
Annual repair estimate.

 APPROXIMATE OR PRELIMINARY
ESTIMATE
• It is also called budget, preliminary estimate. This type of estimate
is prepared in the initial stage of a project. To give a clear idea to
the owner (client) about the amount of cost needed for the project
and to get the approval from necessary sanctioning bodies
(example: from banks to get loan). Documents such as project
drawing plans, details about the land including electricity & water
supply and a full clear report are necessary to carry out the
estimate.
• Commonly the approximate estimate is calculated with relevant to
the previous experience.eg: To calculate the estimate for a house, a
previously (& also recently) completed similar house will be
considered. Here the estimator already knows the rate for 1m2 area
& with that he/she calculates the cost estimate for the newly
proposed area (of similar house).

PURPOSE OF PRELIMINARY OR
APPROXIMATE ESTIMATE
• Preliminary study of the projects.
• Administrative approval
• To investigate feasibility
• For insurance purpose
• For deciding charge
• Tp decide rent for building

 PLINTH AREA ESTIMATE
• As the name implies, this estimate is prepared by multiplying the plinth area of
the proposed building by the plinth area rate of similar building having same
specifications and height that is constructed very recently in the same
locality.
• The plinth area of the proposed building is calculated for the covered i.e.
roofed portion by measuring the outer dimensions at the plinth level.
• The area of courtyards, and other open areas are not to be included while
calculating the plinth area.
• The plinth-area method of preparing estimate gives the approximate cost of
the building to be constructed.

 CUBE RATE ESTIMATE
• This type of estimate done by multiplying the volume of the building by the
unit cubic rate achieved from the previously (also recent) estimate. This
type of estimate is a little bit more accurate than above mentioned
methods and mostly suitable for multi storied buildings. Here the cost of
corbelling (corbel – a piece of stone, wood, brick, or other building material,
projecting from the face of a wall and generally used to support a cornice
or arch), cornice and other works like that are neglected.
Cubic content estimate = Volume of the building X unit cubic rate (known
value)
volume of the building = plinth area (length X breadth of the proposed
building) X height of the building (floor to roof top)
unit cubic rate = total cost of the previously built building / total volume of
that building.

 DETAILED ESTIMATE
• Detailed estimate is prepared by finding out the actual quantities of
different items of the work and then multiplying the cost of per unit item.
Sum of the cost of each item and add to it suitable percentage of work
charge establishment and contingencies, Etc.
• Following are different sheets use to find quantities, cost per unit item ,
etc.
Measurement sheet
Abstract sheet
General abstract sheet

Format of measurement sheet and abstract sheet

RATE ANALYSIS
• Determination of rate per unit of a particular item of work from the
quantities and cost of materials , labors etc. required is termed as rate
analysis.
• Determination of rate depend upon :
1. Market rates of materials
2. Transportation of material
3. Labors involved in construction
4. Contractors profit ( 10% )

ANALYSIS OF RATES HAVE TWO HEADS AND THREE SUB-
HEADS
1) Cost of material
2) Cost of labors
3) Plans and equipment
4) Contractors profit
5) Overheads charges

TERMS USED IN RATE ANALYSIS
• Task work : the quantity of work done by labor in a day is termed as task
work .
• Lead : it is the horizontal distance from center of area of excavation to the
center of placed earth.
• Lift : it is the vertical distance through which the excavated soil is lifted.
• Schedule of rates : it is the list of rates for common items of works and it
is prepared by an engineering department in form of printed bool lets. Due
to changes in market , it is necessary to revised the rates for every years.

PROVISION AND PURPOSES OF DIFFERENT
CHARGES
• Contingencies charges : The miscellaneous incidental expenditure
which cannot be specified in any specific item , is specified as
contingencies charges. the provision of 3% to 5% of the estimated
cost of work is shown as contingencies charges.
• Work charge establishment : during the construction of civil
engineering work, some supervisory staff like supervisor,
watchmen etc. to be appointed on temporary basis. The payment of
such staff are made from work charge establishment . The
provision is about 2% to 3% of estimated cost.
• Quality control charges : number of tests can be conducted with
special equipment to ensure desired quality of work. About 0.5% of
the estimated cost of work is provided.

• Centage charges : sometimes one department undertakes the work
of other department ( local bodies ) . Generally 10% to 15% of
estimated cost.
• Electrification charges : the provision for electrification charges is
about 5% to 8% of estimated cost of work provided.
• Water supply charges : the provision of water supply ( plumbing )
charges about 8% of estimated cost of work is provided.
• Sanitary charges : the provision for sanitary charges or drainage
charges is about 8% of the estimated cost pf work is provided.

TERMED USED IN ESTIMATES
• Prime cost : the details of certain items such as doors and windows fittings ,
water supply and sanitary fittings, types of handrails, electrical fittings, etc. are
not shown in drawing. The details of such items are not work out at time of
preparing estimate but provision is made for these items as a lumpsum amount
in the estimate. This is known as prime cost or prime cost sum.
• Provisional sum : some items of works which are special like installation of air
conditioners, lifts, etc. such items of work cannot be carried out by civil
engineer, therefore a certain amount of sum of money is included in the
estimate. This amount is known as provisional sum.
• Lumpsum : when it is not possible to decide a suitable unit rate for items of
works and it is difficult to measure the work in standard units, the provision is
made up in lumpsum basis in estimate. Such provision is known as lumpsum
provision. Ex. Site clearance, dewatering, dismantling of structure.

• Provisional quantities : Works which are not shown in detailed drawing like
quantities of excavation, foundation concrete , etc. cannot be estimated before
knowing the sub soil information. The quantities of such items are measured at
sites as per drawing. An extra provision for additional quantities for these items
is made in estimate as a provisional quantities.
• Extra items : Such items occurs due to happenings at he site, changes in the
drawing, design and specification and addition, alteration suggested during
execution these items are not cover in contract agreement.
• Spot items : those items which is not possible to fix the amount in the estimate
without observing and studying on the spot like site clearing of the site,
demolition of structure, connecting old existing structure with neat structure,
dewatering, etc.

UNIT OF MEASUREMENT FOR
VARIOUS CONSTRUCTION ACTIVITIES
• The unit of measurements for any construction activities depend on
the nature of work being done, shape and size. They are
determinant of quantities of work being done.
• Following are main principles for measuring units :
 Measurements is based on the finished item of work with detailed description
of it.
 Following order should be maintained : length, breadth, height/thickness.
 Least dimensions should be:
 0.01m in length
 0.01m2 square feet in area
 0.01m3 in volume
 0.001 tons in weight

ITEM AND MEASURING UNITS
• Earthwork : it is measured in CUM or m3. this includes all types of
excavation. Vegetation removal and other extra work is measured
separately.
• Backfilling : it is measured in CUM or m3. this includes all types of
filling works ( generally the excavated material ) vegetation it is
measured removal and other extra work is measured separately.
• Brickwork : it depends on how the bricks are laid.
 4- inch brick work : it is measured in SQM or m2
 8-inch brick work : it is measured in CUM or m3
• Stonework : stone work is measured in CUM or m3.
( note : there should be no deductions fpr small openings like pipe holes for scaffolding and
openings less than 0.1 Sqm. In stonework and brickwork )

• Concrete work :
Reinforced cement concrete : it is measured in CUM or m3
Plain cement concrete : it is measured in CUM or m3
Plum concrete : it is measured in CUM or m3
Chip packing : it is measured in RMT or m
(note : there should be no deduction for volume of pipes or conduits smaller than 0.01 square meter, volume
of reinforcement bars and openings less than 0.1 square meter.)
• Tile flooring : it is measured in SQM or m2. it involves floor or wall tiling
and any other types of tiling work.
• Weathering course : it is measured in SQM or m2.
• Plastering : it is measured in SQM or m2. plaster work which is less than
30 cm in width will be measured in RMT. Openings smaller than 0.5 SQM
should not be deducted.

• Painting : it is measured in SQM or m2. openings smaller than 0.5 SQM
should not be deducted. It involves white washing, varnishing,
distempering, coloring.
• Drip, string course and water coping : it is measured in RMT or m.
• Glazing : it is measured in SQM or m2. polishing and rounding is measured in
RMT.
• Formwork : it is measured in SQM or m2. openings smaller than 0.4 m2
• Centering and shuttering : it is measure in SQM or m2. openings smaller
than 0.4 m2 should not be deducted.
• Scaffolding : it is measured in SQM or m2. openings smaller than o.4m2

• Door/ window framing : it is measured in numbers.
• Hume pipe installation : it is measured in RMT or m. and rate will change
with diameter this involves.
• Waterproofing work : it is measured in SQM or m2.
• Hacking/roughening : it is measured in SQM or m2.
• Fixing GI mesh : it is measured in RMT or m.
• Damp proof course : it is measured in SQM or m2.
• Dismantling : it is measured CUM or m3 and SQM m2 both depend upon
item.

CONCLUSION
• Here, we came to know about the concept of estimating and
costing, their purposes, importance in construction. We can also
understood the types of estimates, data required for estimate,
different terminology used while preparing an estimate. Also this
presentation includes the concept of rate analysis and different
provision used in estimate and their purposes and item and
measuring units.

Thank you

Estimating and costing

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