ESTIMATION

Estimate is a calculation of various items of an

engineering works so as to know its approximate cost
and quantities of various kinds of materials required
with labour involved for its satisfactory completion.
Purpose of Estimating
1) To ascertain the necessary amount of money
required by the owner/contractor to complete the
proposed work.
2) For public construction works, estimates are
required in order to obtain administrative approval,
allotment of funds and technical sanction.
3 To ascertain quantities of materials required in
order to program their timely procurement.
4 To calculate the number of different categories of
workers that are to be employed to complete the
work within the scheduled time of completion.
4) To assess the requirements of Tools, Plants and
equipment required to complete the work according
to the program.
5) To fix up the completion period from the volume of
works involve in the estimate.
6) To draw up a construction schedule and program
and also to arrange the funds required according to
the programming.
7) To justify the investment from benefit cost ratio.
(For ideal investment, this ratio should be more than
one ).
8) To invite tenders and prepare bills for payment.
9) An estimate for an existing property is required
 DATA FOR ESTIMATE
DRAWINGS

SPECIFICATION

RATES
 DRAWING
 Fully dimensioned and to the scale drawings are
required for finding dimensions while doing
measurements

 Following drawings are required

 PLAN
AT A SCALE OF 1 CM = 1 METRE

 ELEVATION AND SECTIONAL ELEVATION

AT A SCALE OF 1 CM = 1 METRE

 DETAILED DRAWINGS
AT A SCALE OF 1 CM = 20 CM
 SPECIFICATION

 GENERAL SPECIFICATIONS

 DETAILED SPECIFICATIONS
 RATES

 Rates per unit of various items of work include

a. The rate of various materials which are used in
construction
b. Labour wages and categories
c. Location of work its distance from source
of material and cost of transport

 Rates can be obtained from P.W.D. schedule of rate book

or can be calculated by “ Analysis of Rates” method.
 ESTIMATE

IN PUTS PROCESS OUT PUTS

DRAWING CALCULATION REPORTS

OF
PRELIMINARY
SPECIFICATION LABOUR ESTIMATE
(SKILLED,
UNSKILLED) OR
RATES DETAIL
MATERIAL ESTIMATE
(Course FINE)

CARRAIGES
 MEASUREMENT

Measurement has a very important place in Planning and

Execution of any Civil Engineering work.

It is required from first estimate to the final completion of

work and payment settlements.
GENRAL RULES
Each item shall be fully described and shall include all
necessary materials, transport, unloading, stacking, storing,
wastage in handling, labour required for finishing the work etc.

Booking of dimensions is done in order of length, breadth or

width and height or depth or thickness.

Dimensions shall be nearest

0.01 m in length
0.01 m2 in areas
0.01 m3 in volumes
0.001 tonnes in weights

Same work with different conditions or stages must be

measured separately stating the condition, height or depth or
distances.
 UNITS OF MEASUREMENTS

 Mass, voluminous and thick works shall be taken in

cubic unit or volume( M3).

 Thin, shallow or surface works shall be taken in

square unit or in area( M2).

 Long and thin work shall be taken in linear or

running unit (RMT)

 Piece works or job works etc shall be taken as

number.
EARTH WORK : IS 1200 Part I
(L X B X H = M3)
Excavation will include
1. Setting out works
2. Site clearance
3. Unauthorized benching or battering
4. Leaving or forming dead men after measurement
5. Leaving steps in sides of deep excavation
6. Bailing out water in excavation
7. Slinging and supporting pipes etc met during excavation.
8. Ramming at bottom
Special pumping other than what is required for
conditions above and tube well/well point dewatering
where resorted to shall each be measured separately
for all stages of pumping,

including intermediate stages unless otherwise

stated, in K.W. Hrs,

or HP Hrs, against separate specific provision(s) made

for the purpose.
 Measurement of earth work is done in M3.
 Measurement shall be taken as the area of the bottom of
foundation trench multiplied by depth of foundation as give
in plans.
 When excavation is in fairly level ground than depth can be
measured from “Dead Man” or “Tell Tales” left out during
excavation.

G PLAN L
TELL TALE

ELEVATION EXCAVATION LEVEL

 When ground is more uneven levels shall be taken
before start excavation by surveying instruments
and block counter are drawn. Then excavation
level can be found.

 When excavation is made in mixed type rock or

soil then measurement for total quantity shall be
made by any above methods. But from total
quantity deduction of volume of one type of rock
must be done and that rock is stacked for
measurement.
SOIL

ROCK

 Except hill side cutting all excavation 1.5 meter

depth is considered as unit lift.
Authorised working space
a) In work which requires formwork;
b) In work which will be covered externally with a damp
proof covering;
c) In work which will be covered externally with protective
masonry work of brick, stone, precast concrete, etc; .
d) Trenches which are to receive post tensioned concrete
ground beams;
e) Special works like guniting, etc; and
f) In work which requires workmen to operate from outside.

Where authorised working space is not so specified the

following shall apply: 600 mm measured from the face of
substructure ( including protective measures, if any) at
lowest level, where extra working space is required. In
addition, for trenches the extra length at each end shall be
1.5 m.
Filling
Lead and Lift

Surface dressing : not exceeding 150 mm deep

Surface Excavation: Excavation exceeding 1’5 m in width as

well as 1O m2 on plan but not exceeding 300 mm in depth

Excavation for cables , pipes etc( trenches): not exceeding

1.5 m in width and for shafts, wells, cesspits and the like not
exceeding 10 m2 on plan shall be so described and measured in
cubic metres.
For depth exceeding 1 m, an allowance of 50 mm/m depth for
each side of trench shall be added to the specified width.

Planking and strutting

Removing trees: not exceeding 300 mm girth shall be
measured in square metres,
CONCRETE : Part II

(L X B X H = M3)
 Plain Cement Concrete is measured in m3
 Reinforced Concrete :
a. Unless other wise specified all concrete work shall
be measured in M3.
b. Form work should be measured, if required, in
square meter.
c. Reinforcement should be measured separately and
unit is K G.
d. Concrete finishes are not measured separately
including measurement for hacking of surfaces.
e. No deduction shall be made for following :
1. Volume occupied by reinforcement
2. Opening up to 0.1 m2
3.Volume occupied by pipes, conduits etc not
exceeding (100)cm2 in cross section.
4. Small voids not exceeding 40 cm2 in cross section.
5. Chamfers, moldings, grooves up to 10 cm in width
and 15 cm in girth
6. Ends of dissimilar materials upto 500sqcm in c.s
f. columns shall be measured from top of column base to
underside of first floor slab and then top of floor to
underside of floor slab above.

H
g. Beam shall be measured from face to face of column
1. Depth of beam shall be measured from bottom of
slab to bottom of beam.
2. For inverted beams depth shall be measured from
top of slab to top of beam

NORMAL BEAM
DEPTH OF BEAM

INVERTED BEAM

h. Slabs is measured in M3, length and breadth shall be

taken as per plan and depth as specified .
i. Lintels shall be measured in M3 and bearing of lintels
should not be less than 0.12 m to 0.15 m.
Precast cement concrete

Classification of work METHOD OF MEASUREMENT

Roof slab, floors etc in sqm
Beams unit and columns running metre
Channel units “
Kerbs , edging “
Doors and window frames in running metre stating the size
Water tank in numbers
Fencing posts in nos or running metre
Jallies in sqm stating thickness
Cavity walls
Forming of cavity shall be measured in square metres. The description shall state
the width of cavity, the material, size, shape of ties and their number per square
metre.

Measurements of cavity shall be taken along a plane at centre of cavity; deduction

being made for all openings and solid portion of walls.

Labour and material for closing cavities at the jambs, sills and heads of openings
shall be described and measured separately in running metres.

Items shall include use of cores for keeping cavity clear, uniform, and forming the
requisite weep and vent holes.

Concrete fencing posts, corner posts, straining or terminal posts and struts shall
be classified according to size as follows:

a) Those having an average sectional area not exceeding 100 cm2,

b) Those having an average sectional area exceeding 100 cm2 but not exceeding
250 cm2, and
c) Those of an average area over 250 cm2.
Grout Holes — The length of grout holes drilled either for pack grouting or
pressure grouting through concrete shall be measured in running metres. Grout
holes drilled through plate steel liners shall, however, be enumerated separately.

Grout Pipes and Fittings — Grout pipes and fittings provided for grouting shall be
measured in kilograms and weight of all pipes and fittings shall be derived either by
actual weighment or from known weights and lengths.

Water Pressure Testing — Measurement for water pressure testing shall, where
necessary, be made separately for each hole and enumerated.

Measurement for grouting shall be made on basis of the weight of cement in grout
actually forced into holes. Stone dust and other additions, if used, shall be
measured separately in loose dry state before mixing and shall be measured by
boxes of approved size and design.
Expansion jts is measured in running metre stating the depth and width of joint.
Damp proof course and Waterproofing concrete
Cutting in concrete –
Grooves, chases and like shall be measured in running metres stating girth
Holes, openings shall be measured per centimetre of depth of cutting and classified
as
Upto 250sqcm in area
Exceeding 250 sqcm and upto and including 0.1 sqcm area.

Toothing and Bonding – measured in sqm

BRICK WORK : Part III
( L X B X H = M3)
Brickwork shall include
1. Raking out jt
2. Preparing tops of existing walls
3. Leaving holes for pipes
4. Plumbing to angles
5. Building hold fasts, fixing bricks etc
6. Building in ends of beams, sills etc
7. Forming opening and flues for which no deductions are made
8. Bedding wall plates , lintels sills, corrugated sheets in wall
Brick work generally measured in M3 unless specified.
Brick work one brick thick (20 cm) or less shall be measured separately in M2.
No deduction shall be made if
a. opening up to 0.1 M2 in area.
b. cement concrete blocks for hold fast and holding down
bolt.
c. Ends of dissimilar materials like beam, lintels etc upto 0.1
sqm in section.
d. Iron fixtures such as hold fats for doors and windows ,
pipes upto 300mm diameter.
e. Wall plated, bed plates where thk not exceeds 10 cm and bearing does not
exceeds full thk of wall

Deduction shall be made for

a. door, window opening
b. lintels or arches above door or openings.
c. deduction for different shapes are made as follows
DEDUCTION
[ (l x h) + (l x 2/3 r) ] x thickness of wall

DEDUCTION
Lm x t x thickness of wall
Brickwork circular on plan to a mean radius not exceeding 6 m
shall be measured separately and shall include all cutting and’
waste and ‘templates.

Honey combing brickwork is measured in square meter

Cornice should be measured in running meter.

Partition wall are measured in square meter.

Plain corbels, string courses, sills, cornices, drip courses, over

sailing courses, and other projections, etc, of splayed,
bullnosed or any other type of purpose-made or cut bricks
shall be fully described and measured in running metres
stating depth and width of projection. No deduction shall be
made from masonry of wall for the bearing portion of drip
course, bearing of moulding and cornice.
Cutting chases and rebates grooves in brick work shall be
measured in running metre stating the girth and shall be
classified as
girth not exceeding 10cm
Exceeding 10cm but not exceeding 20 cms in girth
When exceeding 20cms in girth shall be measured in sqm
by its length.

Cutting holes
a) Holes not exceeding 400 cms in area, and
b) Holes exceeding 400 cms and not exceeding 0.1 sqm in
area.
Cutting openings exceeding 0.1 ma in area in walls one
brick thick and less shall be measured in square metres
and in walls exceeding one brick thick shall be measured in
cubic metres.
Toothing and bonding
STONE MASONARY : IS 1200 Part IV
(L X B X H = M3)
 MASONARY SHALL BE MEASURED IN CUBIC METER

 FACE WORK SHALL BE MEASURED IN SQUARE METER

 Stone masonry in arches
For spans upto 2m measured separately and include centering
Above 2m measured separately and centering measured separately
 Underpinning
 Chases and rebates
 Cutting holes
ADDITIONAL LABOUR IN DRESSED STONEWORK

The following labours shall be measured separately in square

metres when exceeding 10 cm in girth or width and in
running metres if not exceeding 10 cm in girth or width, as
shown below unless included in the main item:

• a) Chamfers, arrises, or splays not exceeding 1.5 cm in width;

• b) Chamfers, arrises, or splays exceeding 1.5 cm but not exceeding
• 10 cm in width;
• c) Rounded bullnoze-angles or mouldings or hollow angles;
• d) Rebates, grooves ( square, hollow or dove-tailed ) in facework;
• e) Rebates, grooves ( square, hollow or dove-tailed ) for joints,
• tongues of sills, etc; and
• f) Cutting chisel drafted margin.
Method of measurement of
Formwork
Part 5
Formwork shall include foll.
Splayed edges, notchings, allowance for overlays and passing at angles , sheathing
battens, strutting, bolting, nailing, wedging, easing, striking and removal.
All supports, struts, braces, wedges as well as mud sills , piles or other suitable
arrangements to support the formwork
Bolts, wire ties, clamps, spreaders, nails or any other item to hold the sheathing
together
Working scaffolds, ladder, gangways and similar items
Filleting to form stop chamfered edges or splayed external angles not exceeding 20
mm wide to beams, columns and the like
If required, temporary openings in the forms for pouring concrete , inserting
vibrators, and cleaning holes for removing rubbish from the interior of the
sheathing before poring concrete
Dressing with oil to prevent adhesion
Raking or circular cutting
Formwork shall be generally classified as follows and measured separately, unless
specified otherwise:

a)Foundation, footings, bases of columns, etc; and mass concrete

b) Flat surfaces, such as soffits of floors, roofs landing and the like; where floors
exceed 200 mm in thickness the formwork shall be measured separately stating the
thickness

c) Vertical surfaces, such as walls, partitions and the like, including attached
pilasters, buttresses, plinth and string courses and the like, etc;

d) Sloping or battering surfaces, including folded plates;

i) Where inclination to horizontal plane does not exceed 30°
(requiring shuttering only on the underside);
ii) Where inclination to horizontal plane exceeds 30° (where
shuttering may be provided both on underside and upper-side, if required) (only
underside area to be measured);
e) Arches
i) up to 6 m span and ii) above 6 m span
f) Cylindrical Shells ( Area of Underside to be Measured )
i) radius less than 3 m and ii) radius above 3 m
Method of measurement
Formwork shall be measured in square metres as the actual surfaces in contact
with the concrete
Where formwork is required to be lined with wall board, hardboard, polythene
sheet
No deduction shall be made for openings up to 0.4sqm. No deduction shall be made
for any opening/cutouts when slip form technique is used.
Raking or circular cutting and rounded or moulded edges shall be measured in
running metres. Moulded stopping shall be enumerated.
Formwork to secondary beam shall be measured up to the sides of main beams, but
no deduction shall be made from the formwork of the main beams where the
secondary beam intersects it.
Formwork to beam shall be measured up to sides of column, but no deduction shall
be made from the formwork to stanchion or column casings at intersections of
beam.
Method of measurement of
Steel work and Iron work
Part 8
 STEEL AND IRON WORK : K. G.
Reinforcement shall be measured to nearest 0.005m.
Dimensions like cross sections to nearest 0.001sqm

STRUCTURAL STEEL :
Normally steel work shall be measured by weight.
Unless otherwise specified weight of cleats, brackets, packing pieces, bolts, nut, washers,
distant pieces, gusset plates etc shall be added to the weight in structural steel.
In riveted work an additional 2.5% of weight of structure is made.
• Deduction to rivet hole is made if area exceeds 0.02sqm and for notch if its area exceeds
0.05 m2. For other type of openings like holes for service pipe etc, deduction shall be
made if its area exceeds 0.1 m2.
In welded section welding material is not measured.

STEEL REINFORCEMENT :
Bar reinforcement shall be measured by weight in KG and shall include cutting to length,
hooked ends, cranking or bending, authorized overlaps, chairs and separators.
Various items of steelwork shall be classified and measured separately under following categories. Wo
in each classification shall be described. Bolted, riveted and welded structures shall be described
such and
measured separately:
a) Rolled sections (joist, channel, angle or tee) fixed independently without
connecting plates;
b) Rolled sections fixed with connecting plate or angle cleats as in main and crossbeams, hip and jac
rafters, purlins connected to common rafters and the like.
c) Rolled joists, with or without stiffeners in grillages (the weight of stiffeners shall be added to th
mass of joists);
d) Compound girders;
e) Plate girders (stating type and overall height of girder);
f) Lattice girders, aerial masts, tank staging and like (stating details of members and overall height
structure);
g) Single stanchions composed of rolled joists or channels with caps, bases, splices, angle brackets, etc;
h) Compound stanchions with caps, bases, splices, angle brackets, etc;
j) Trusses and trussed purlins (stating spans and overall heights);
k) Framing of cladding and glazing;
m) Crane gantry rails including fastenings:
n) Staircases including stringers, treads, landings, handrails, etc;
p) Plates (plain or chequered), square cut or notched, holed (ordinary or
countersunk) without any attachments;
q) Plates of classification (p) above with riveted, bolted or welded attachments;
r) Running rails and girders for sliding doors;
s) Platework with or without stiffeners for: bunkers,chutes, chimneys including
ladders, tanks with or without covers including stays but excluding stagings,
gutters and downpipes, and furnace shell.
t) Anchor bolts, holding down bolts including all fittings and sag rods;
u) Wind ties to roofs, strakes for wooden bridges, cores for handrails (straight
portion), running bars for doors and fencing posts and struts;
v) Framed work, such as grills, gratings, framed guard bars, ladders, walkways,
railings, brackets and similar work;
w) Straps, hooks, clamps, holdfasts, wall ties, insets, knee pieces, and similar works;
y) Ornamental work as in grills, balustrades, and curved, ramped and scroll portion
of cores for handrails; and
z) Steelwork for: doors, hydraulic gates, and cassions and well curbs.
z1) Purpose made butt hinges for fixing to stone or concrete door and window
frames.
Binding wire for reinforcement shall not be measured but
shall be included in item list.

In case of welding of joint is authorized the same shall be

described, joints butt welded shall be measured in numbers
and lap welded shall be measured in running meter of length
of weld.

Plain or barbed wire fencing shall be fully described and

each line shall be measured in running meter.

Collapsible gate shall be measured in square meter describing

details of gate including erection, and securing hold fast.

Rolling shutters /grills shall be measured in square meter.

Steel doors and windows , ventilators shall be measured in

square meter
TYPES OF ESTIMATE
 Types of Estimates

A preliminary or approximate or rough Estimate

Detailed Estimate
Revised Estimate
Supplementary Estimate
Combination of Revised and Supplementary
Estimate
Annual Maintenance or Repair Estimate (A.R. or
A.M. Estimate)
Approximate Estimate
This is made to find out an approximate cost in a short
time
Enable the responsible authority concerned to consider the
financial aspect of the scheme for getting sanction to the
same.
This estimate is prepared after preliminary investigation,
preliminary surveying and where required sub-soil
investigation and tests to determine the safe bearing
capacity may be conducted.
A line sketch of the project according to its requirements,
may be required. During presentation of the estimate
detailed surveying, design, drawings etc., are not required.
Rates are determined either from practical knowledge or
from records for similar works.
Such an estimate is prepared adopting different methods
for different types of works.
Purpose of an approximate estimate
(i) To investigate Feasibility
(ii) To save time and money
(iii) To investigate Benefit and comparison of cost with
utility
(iv) Adjustment of Planning
(v) To obtain Administrative Approved
(Vi) For Insurance and Tax schedule
The estimate is accompanied with a brief report
Stating the sources of proposals
Necessity or demand provisions or accommodations
made,
validity
Basis on the estimate, rates and how the expenditure
involved can be met .Beside the report the estimate
is provided with a line plan, site or layout plan, soil
testing by trial boring etc.
Approximate Methods of Estimating for
Buildings
• Plinth area method
• Cubic rate method
• Service unit method
• Bay method
(1) Plinth area or square-meter method
To prepare an estimate by this method the plinth
area of a building shall be determined first. Plinth
area is worked out from Floor area, or carpet area or
Covered area or Remote area of a building. Similarly
the circulation area should be known in order to
calculate the plinth area of a building.

The plinth area is the built up covered area

measured at the floor level of the basement or of any
storey of a building.
Plinth area rate depends upon
1. General specifications
2. Price level
3. Shape of building
4. Design of building and provisions made
5. Arrangement of rooms, circulation area and provisions made for
sanitary blocks
6. Location
Cubic rate or cubic metre method :-

By this method the volume or cubic content of the

proposed building is worked out and multiplied by the
rate per cubic volume of similar building in that
locality, constructed recently.
So the preparation of such an estimate depends on
(i) determination of total volume, in cubic metres, of
the proposed buildings and
(ii) determination of the present rate per cubic
metre of similar buildings constructed recently in
that locality.
Service Unit Method

In this method all costs of a unit quantity such as per

km for a highway, per mere of span for a bridge, per
classroom for school building, per litre for water
tank., are considered first and the estimate is
prepared by multiplying the cost per corresponding
unit by the number of units in the structure.
Bay Method
In this method, the approximate estimated cost =
Number of bays in the proposed structure x cost of
one such bay.
Bays are compartments or similar portions of a
structure. When the area of a structure consists of
similar cabins or parts railway platform, factor
sheds, etc. which have been built up with
intermediate columns or with roof trusses on walls
placed at equal distances with the same roofing on
top of those supporting members, then the area may
be divided from center to center of the supports .
Each such division may be treated as a Bay.
To form the basis for calculation of materials and labour CBRI
has recommended the following formulae which, after a study
of the specifications have been selected for this analysis.
The table given is for buildings of different shapes and plinth
areas varying from 30 to 300 sqm.
These information are useful for preparation of building cost
index, preplanning of materials and labour requirements in a
building project.
Equations for materials requirements (as recommended by
CBRI) A= Plinth area in sqm.
Name of material Equations for Four storey (super
Single storey Double storey structure RCC framed)

Bricks (% Nos) 2.26A + 66.8 2.15A + 63 -26.2 + 2.56A –

0.0096A2
Cement (Tons) 0.153A + 0.57 0.145A +0.54 0.182A – 0.35
Steel (Kgs) 21.3A - 314 21.97A - 305 - 1491+ 92A- 0.36A2
Sand (Cum) 0.47A- 7 0.376A – 5.6 0.361A- 0.38
Coarse Aggregate 0.176A – 0.21 0.178A – 0.21 0.295A – 0.75
20mm and down (cum) 0.145A + 1.5 0.075A + 0.78 0.45 + 0.0027A +
40mm and down (cum) 0.0001A2
Brick aggregate (cum) 0.113A-0.83 0.056A -0.42 0.021A+0.01
Lime (quintal) 0.145A – 0.35 0.073A- 0.17 0.063A-0.08
Surkhi (cum) 0.052A-0.37 0.026A-0.18 0.01A
Timber frames and 0.019A +0.23 0.019A +0.23 0.02A+0.11
shutters(cum)
Primer (litres) 0.068A 0.068A 0.061A+ 0.56
Paint (liters) 0.108A +0.27 0.108A+ 0.27 0.085A+1.93
 Equations for Labour requirements (For superstructure
only) A= Plinth area in sqm.

Labour in days Equations for Four storey (super

structure RCC framed)
Single storey Double storey

Mason 1.335A+28 1.335A + 26 1.67A-2

Carpenter 1.184A-9 1.194A-9 1.61A

Painter 0.089A 0.089A 0.09A

Blacksmith 0.269A-4 0.274A-4 -16+1.01A-0.004A2
Mazdoor 4.769A+32 4.91A+33 5.49A-9.2
Equations for materials and Labour requirements for superstructure in
four storeyed (RCC framed building) A= Plinth area in sqm.

Materials Equations Labour(days) Equations

Cement (Tons) 0.0204A-0.014 Masom 0.023A

Steel (Kgs) -171A-10.46A- Mazdoor 0.343A
0.041A2
Sand (Cum) 0.036A Carpenter 0.05A
Coarse 0.071A-0.01 Blacksmith -1.6+0.1A-0.0003A2
Aggregate
20mm and down
(cum)
 FSI = Total Built up area of all floors
Plot area
With respect to the Building bye laws, the permissible
plinth area of that particular building can be found out and
the Approximate cost can be worked out.
Approximate estimate for main parts of building services like
Sanitary,
Water supply,
Drainage,
Electrification,
Boundary wall,
Roads if any, cost of land etc., are made separately.
At the end a General Abstract of cost is drawn. Provisions
of contingency @ 5% to 10% is added with the Abstract
which is the total approximate cost of the project.
Sanitation and Water Supply Add 8 % of Building cost
Electrical Wiring Add 9 % of Building Cost
Electrical Fans Add 4 % of Building Cost
Cost Of Different parts or % break up of
building
Earthwork in Excavation 0.5 % of Whole Cost
Concrete in Foundation 5 % of Whole Cost
Damp Proof Course 1 % of Whole Cost
Brickwork 34 % of Whole Cost
Roofing 20 % of Whole Cost
Flooring 6 % of Whole Cost
Doors and Windows 16 % of Whole Cost
Plastering and Pointing 10 % of Whole Cost
White Washing , Colour Washing 2 % of Whole Cost
Miscellaneous 5 % of Whole Cost
100 % of Whole Cost
COST BREAK UP
Direct and overhead cost
Direct Cost on Actual Work 85% of Whole Cost
Overhead Cost Due to Establishment 15 % of Whole cost

Cost On Account Of labour 30 to 35 % of Whole Cost

Cost On Account Of Material 70 to 65 % of Whole Cost

Cost Of Foundation and Plinth 10 to 15% of Whole Cost

Cost Of Superstructure 90 to 85 % of Whole cost
Approximate cost for Bridge , Culvert and
Road Works

Preliminary estimates are prepared per km basis. The total

spans for bridges or culverts are surveyed separately and
their costs are worked out from the metre span. The total
costs of roads and waterways are added to find the
preliminary estimated cost.
Construction Cost Index

If it becomes necessary to change the actual unit cost due to variations in

construction costs, the same can be carried out with the help of a simple device
known as Construction Cost Index.

This device shows the relative change s in the cost of specific or group of times
over a certain period of time.

The procedure of preparing is

In =∑ ( P1* W/P2*100)

Where In is construction cost index for the year in consideration

P1 is the current price for the year in consideration
P2 is the base year prices
W Is the weighted average of the concerned item

The term weight is used to mean the relative importance of the different material
and items of work in the construction of an index.
All material and items are not of equal importance and hence it becomes necessary
to assign necessary weightage to each of them in proportion to the influence that
they exert in the final result.

The weight may be fixed on quantity basis or value basis.

The relative importance of the item of construction is generally affected by

various factors such as structural design , specifications , better planning, economy
in construction cost etc.

Construction cost index refers to the changes in prices of the group as a whole and
it indicates the average of certain specialised items contributing to the cost of
structure.
NBO( National Building Organisation) weight % for double
and triple storeyed load bearing residential building
COST OF MATERIAL
Cost Of Brickwork 17 % of Whole Cost
Cost Of Cement 18% of Whole Cost
Cost of Sand 05 % of Whole Cost
Cost Of Aggregates 08% of Whole Cost
Cost Of Steel Bars 10 % of Whole Cost
Cost Of Timber 15 % of Whole Cost
Wages Of Labour 27 % of Whole Cost
100 % of Whole Cost
Detailed Estimate
This includes the detailed particulars for the
quantities, rates and costs of all the items
involved for satisfactory completion of a project.
Quantities of all items of work are calculated
from their respective dimensions on the drawings
on a measurement sheet.
Multiplying these quantities by their respective
rates in a separate sheet, the cost of all items of
work are worked out individually and then
summarised, i.e., abstracted (which is the detailed
actual estimated cost of work)
Such a detailed estimate is prepared for
Technical sanction.
Administrative approval
Execution of a contract with the contractor.
How to prepare a detailed Estimate:
The unit-quantity method is followed to prepare a
detailed estimate.
In this method the rates per unit work of one item
(viz., one cu. m. concrete, one cu. m. brickwork etc.)
including profit are considered first and the total
cost for the item is found by multiplying the cost per
unit of the rate by the number of units.
 The procedure for the preparation of a detailed estimate is
divided into two parts.
(a) Detail of measurement and calculation of quantities is the
first part. Respective measurements for dimensions of all
individual items involved in the whole work arc taken off from
the drawing of the work and entered in the respective
columns of a standard Measurement Form as shown below.

Item Description No. Length Breadth Height Qty

No or Particulars
Abstract of Estimated Cost is the second part in the
preparation of a detailed estimate. The cost of each and every
individual item of work is calculated by multiplying the quantity
computed in the Measurement Form with the specified rate in
a tabular form known as ‘Abstract form' as shown below

S. No Description Quantity Unit Rate Unit of rate Amount

or Particulars
This estimated cost is increased by 3% to 5% for all
unforeseen expenditure and is called contingency Fund.
To maintain additional supervising staff at the work site and
called the ‘Work charged' establishment a amount of 21/2% is
directly charged to the estimate prepared from the item of
work
For big projects an amount 1% to 1 1/2% of the estimated cost
is also provided to purchase special Tools and Plants for
specific purposes .
The detailed estimate is generally accompanied
(1) Report.
(2) Specifications (for departmental works,
departmental specifications followed)
(3) Drawings consisting of (a) Plans, sections and
elevations, (b) Site plan or layout plan or Index plan.
(4) Design charts and calculations.
(5) Particulars of rates. In schedule of departmental
rates this is mentioned otherwise the analysis of rate
is required.
( 1) The total estimated cost and the different items
of works required to complete a project can be
known.
(2) This is the basis on which percentage rate
tenders are called after excluding the amounts for
contingency and work-charged establishment.
(3) This is a part of a tender document and a
contractor can arrive at his own rates from the
schedule of work described in the description
column-
(4) This is the basis on which bills are prepared for
payment.
(5) Comparative costs of different items of works
can be known
 Taking Out Quantities

The procedure by which quantities of the various items in a

particular structure are worked out is known as taking out
quantities.
The quantities are obtained by studying in detail the drawings
of the structure.

Methods of taking Out

English method
PWD method
English method of taking out quantities

(1) Taking off;

(2)Grouping
(3) Billing

Thus, the quantities of the various items are worked out an a

measurement or dimension form and then quantities of
identical items are grouped together and written on an
abstract form.
The measurement form or the taking – off sheet or the
dimension sheet is a full – sized paper, double ruled.
 (1) (2) (3) (4) (1) (2) (3) (4)

Column (1) is called the timesing column.

Column (2) is called dimension column.

Column (3) is called the squaring column.

Column (4) is called the description column, in which , the

brief description of the item is written. The right-hand side
of this column is used for rough work and is known as the
waste.
In the dimension column, the length, the breadth or width and
the height or depth are written in sequence in vertical
direction. The multiplication giving the final quantity is then
entered in the squaring column.

(1) (2) (3) (4)

4.0 This indicates 24 cubical content
3.0 24.0
2.0

4.0
3.0 12.0 This indicates 12 superficial contents

4.0 4.0 This indicates linear measurements

No.5 This indicates no.

The following column is used to indicate the number by which
the measurements are to be multiplied. It should be
remembered that an item timesed can be timesed again as
shown below.

3/ 4.0 This indicates the cubical

3.0 72.00 contents are to be multiplied by
2.0 3.

2/5/3 4.0
This indicates the cubical
3.0 720.00
contents are to be multiplied by
2.0 3x5x2= 30
When the measurement are to be added and not to be
multiplied, the process known as dotting on is adopted. A dot
below a figure in the timesing column indicates an addition.

2 4.0
. 3.0 120.00 This indicates that the cubical contents
3 2.0 are to be multiplied by 3+2 = 5

2 3 4.0
. 3.0 240.00 This indicates that the cubical
2 2.0 measurements are to be multiplied by
(3+2) x 2= 10

3 3 2 4.0
This indicates that the superficial
. . 3.0 540.00 measurements are to be multiplied by
2 1 (2+1)x(3+=2)x3 = 45

After working out the quantities of various items an

abstract is prepared in which the items are classified ,
grouped and arranged accordingly
Features of the English method

(1) The quantities are found out in the sequence of

measurements irrespective of items of work and
sequence of execution.
(2) The grouping is a separate process and it is followed
along with the process of billing on the abstract
form.
(3) The chances of omitting any measurements are
reduced.
(4) The method is lengthy and it requires more time.
P.W.D. method of taking out quantities

The three processes, namely , taking off, grouping and billing,

are also involved in this method.

1. But the first and second processes of taking off and

grouping are carried out on the quantity sheet.
2. The measurements are recorded item wise and the items
are arranged in the sequence of execution.
3. The third process of billing is done on the abstract form
as in case of the English method.
4. Thus in this method, the grouping will appear on
measurements form as well as on the abstract form.
Features of P.W.D. method are as follows

(1) The quantities are found out in the sequence of

execution, irrespective of the sequence of
measurements.
(2) The grouping process is eliminated in the sense that
the measurements are directly grouped on the
quantity sheet.
(3) There are chances of missing some measurements.
(4) The method is easy and it requires less time.
Quantities are worked out by any one of the
Methods
Short Wall long wall method
Center line method
A Quantity Estimate or Quantity Survey
This is a complete estimate or list of quantities for
all items of work required to complete the concerned
project. The quantity of each individual item of work
is worked out from respective dimensions on the
drawing of the structure. To find the cost, quantity is
multiplied by the rate per unit for that item. The
purpose of the Bill of quantities is to provide a
complete list of quantities necessary for the
completion of any engineering project and when
priced gives the estimated cost of the project.
(4) Revised Estimate
A revised estimate is a detailed estimate for the
revised quantities and rates of items of works
originally provided in the estimate without material
deviations of a structural nature from the design
originally approved for a project.
It is accompanied with a comparative statement
abstract form showing the probable variations for
quality , rate and amount for each item of work of
the project as compared with the original estimate
side by side stating the reasons of variations.
A revised estimate is prepared and submitted for
fresh technical sanction.
Required for the following reasons-
(i) When a sanctioned estimate is likely to exceed by
more than 5% either from the rates being found
insufficient or from any cause whatsoever except
important structural alterations
(ii) When the expenditure of work exceeds or is likely
to exceed be more than 10% of the administrative
approval (for work more than Rs. 5 lakhs)
(iii) When there are material deviations from the
original proposal but not due to material deviation of
a structural nature
(iv) When it is found that the sanctioned estimate is
more than the actual requirement
5) A Supplementary Estimate
While a work is in progress, some changes or
additional works due to material deviation of a
structural nature from the design originally approved
may be thought necessary for the development of a
project.
The method of preparation of a supplementary
estimate is the same as that of a detailed estimate
and it should be accompanied by a full report of the
circumstances which render its necessity .
The abstract must show the amount of the original
estimate and the total of the sanction required
including the supplementary amount.
6) Combination of Revised and
Supplementary Estimate
Necessary to revise the original estimate due to
increased volume of original proposed work
Sanction of supplementary works.
For such a case a revised estimate is prepared for
the increased volume of original work and a detailed
estimate for the supplementary works not included in
the original schedule.
The amount of supplementary estimate is added to
the revised estimate, showing the amount separately,
Thus the total amount of the revised estimate
includes tile amount for supplementary works also
Revised estimate
(i) This is required when the sanctioned So, a revised
is due to material deviation from nature from the
design originally approved the original proposal,
(ii) It is accompanied with a comparative
(iii) Revised estimate is required due to change
Supplementary estimate
(i) This is required due to supplemental)' works amount is
exceeded due to change of rates which are fairly
independent of the work at or addition of works fairly
dependent on first sanctioned, So, supplemental estimate
the work at first sanctioned.
ii) No comparative abstract form IS required, statement
abstract form showing the probable cost. This is an
estimate for additional works able variations for quantity,
rate and only. The abstract shows the original estimate
amount against each item ,of work in- mate and the total
amount of the sanction involved in the project. required
including supplemental)' amount
(iii) Supplementary estimate is required due to of rate or
quantity of materials, so no ad- some new works or due to
change of design, additions or revisions of drawings is
Revised Estimate and Supplementary Estimates due to
reduction of cost (following P. W .D. manual).
In cases, where a substantial section of a project costing not
less than 5% of the total sanctioned cost of the project is
abandoned or where material deviations front the original
proposals are expected to result in substantial savings, the
estimate is revised by the department and intimated the
Engineer-In-Charge for execution of the work.
But, in cases where the saving is due to a material deviation of
a structural nature from the design originally approval
supplementary estimate is prepared for a revised technical
sanction.
 
A complete Estimate
This is an estimated cost of all items which are
related to the work in addition to the main contract
or to the “detailed estimate".
One may think that an estimate of a structure
includes only the cost of land and the cost of the
main or abstracts or labour , materials and
supervision.
In addition, there are many other cost items to be
included.
Annual Maintenance or Repair Estimate
For proper function an estimate is prepared for the
item which require renewal, replacements , repairs
etc. in the form of a detailed estimate.
For buildings, such item of work like white washing,
colour washing and painting of doors and windows etc.,
Quantities are based on the previous measurements
recorded in the Measurement books as “Standard
Measurement books”.
The total estimated cost of maintenance of a
structure is generally kept within the prescribed
limits on percentage basis (variable according to the
age and importance of the structure)
Types of Construction Cost Estimates according to function

A construction cost estimate serves one of the three basic functions: design, bid
and control.
Design Estimates

For the owner or its designated design professionals, the types of cost estimates
encountered run parallel with the planning and design as follows:

􀁺 Screening estimates (or order of magnitude estimates)

􀁺 Preliminary estimates (or conceptual estimates)

􀁺 Detailed estimates (or definitive estimates)

􀁺 Engineer's estimates based on plans and specifications

Bid Estimates
For the contractor, a bid estimate submitted to the owner either for competitive
bidding or negotiation consists of direct construction cost including field
supervision, plus a markup to cover general overhead and profits. The direct cost of
construction for bid estimates is usually derived from a combination of the
following approaches.

􀁺 Subcontractor quotations

􀁺 Quantity takeoffs

􀁺 Construction procedures.
Control Estimates
For monitoring the project during construction, a control estimate is derived from
available information to establish:

􀁺 Budget estimate for financing

􀁺 Budgeted cost after contracting but prior to construction

􀁺 Estimated cost to completion during the progress of construction.

Both the owner and the contractor must adopt some base line for cost control
during the construction. For the owner, a budget estimate must be adopted early
enough for planning long term financing of the facility.

Consequently, the detailed estimate is often used as the budget estimate since it is
sufficient definitive to reflect the project scope and is available long before the
engineer's estimate.
As the work progresses, the budgeted cost must be revised periodically to reflect
the estimated cost to completion.

A revised estimated cost is necessary either because of change orders initiated by

the owner or due to unexpected cost overruns or savings.
What is Specification
A specification is a specific description of a particular
subject.
An engineering specification contains detailed description of
all workmanship and materials which are require to complete
an engineering project in accordance with its drawings and
details.
The technical drawings of a structure will show the
proportions and relative positions of the various components
of the structure.
Many a time it is not possible to furnish the information on
the drawing, regarding the quality of materials to be used
an the quality of workmanship to be achieved during
construction, due to shortage of space.

This data regarding the material and workmanship is

conveyed in a separate contract document which is known as
the “Specifications” for the work.

Thus the drawings with the specifications “will completely

define the structure”.

The “specification” is furnished separately along with

drawing and is an essential part of all engineering contracts.
Necessity of Specification
i) The cost of an unit quantity of work is governed by its
specification.
ii) Specifications of a work are required to describe the
quality and quantity of different materials required for a
construction work and is one of the essential contract
documents.
iii) This also specifies the workmanship and the method of
doing the work.
iv) A work is carried out according to its specification and the
contractor is paid for the same. Any change in specification
changes the tendered rate.
v) As the rate of a work is based on specification a contractor
can calculate the rates of various items works in a tender with
his procurement rates of materials and labour. Thus tender
paper without specifications of work is baseless, incomplete
and invalid.
vi) Specification is necessary to specify the equipments , tools
and plants to be engaged for a work involved in a project.
vii) The necessity of specifications is to verify and check the
strength of materials for a work an thus enables to procure
them beforehand.
viii) Specification is an essential contract document and is
required for Arbitration or court cases.
How to write specification ?
a) Description of materials
b) Workmanship
c) Tools and plants ( T. & P.)
d) Protection of new work
e) Expression
f) Clauses of the specifications
Specifications depend upon the
Site conditions
Nature of work
Purpose for which the work is carried out.
Types of Specifications :-

a) General Specifications.
b) Detailed specifications.
 
General specifications :- In general specifications, nature
and class of works names of materials and proportion that
should be used in the various items of works are described.
Only a brief description of each and every item is given. It is
useful for estimating the project.
Without going through the lengthy detailed specifications,
general information for the quantities of materials, nature and
class of work can be known from the general specifications,
but they do not form part of the contract document.
GENERAL SPECIFICATION OF A FIRST CLASS BLDG
Foundation and Plinth: Ist class brickwork in lime mortar or
Cement Mortar 1:6 over lime concrete or 1:4:8 of Cement
Concrete.
Damp Proof Course: Should be 2.5 cms thk cement concrete
1:11/2:3 mixed with one kgs of Impermo per bag of cement or
other standard water proofing materials and painted with 2
coats of bitumen.
Superstructure: I st class brickwork with lime mortar or 1:6
cement mortar . Lintels ver doors and Windows shall be of RCC
Roofing: Shall be RCC slab with an insulation layer and lime
concrete terracing above, supported over R.S.Joists or RCC
beams As required. Ht of rooms shall not be less than 3.7m.
Flooring: Drawing room and dining room floors of mosaic,
Bath ,WC and dado of mosaic (terrazo). Bed rooms coloured
and polished of 2.5cms cement concrete over7.5cms lime
concrete polished. Floors of others shall be 2.5 cms cement
concrete over7.5cms lime concrete polished.
Finishing: Inside and outside shall be 12 mm cement lime
plastered .Drawing,dining and bed rooms inside shall be
distempered others white washed 3 coats. Outside shall be
coloured snowcem washed two coats over one coat of white
wash.
Doors and Windows: Chaukats shall be seasoned teak
wood.Shutters shall be Teak wood 4.3 cms thk panelled glazed
or partly panelled and partly glazed as required with additional
wire gauge shutters. All fittings of brass. Doors and Windows
shall be Varnished or Painted two coats with high class enamel
paint over one coat of priming.Windows shall be provided with
iron gratings or grills.
Detailed Specifications :-
The detailed specifications form a part of the contract
document. Detailed specification for a particular item specify
the qualities, quantities and proportions of materials, and the
method of preparation and execution for that particular item
of work in a project.
The detailed specifications of the different items of woks are
prepared separately and they describe what the works should
be and how they shall be executed and constructed.
Physical chemical and electrical tests if any requires for then
finished work to ensure the desired strength or quality are
specified in the detailed specification.
The type of machinery, equipments and special tools and plant
their method of operation when involved during execution are
described in the detailed specification.
The method and duration of protection of finished works as
required are specified in the detailed specification.

This also specify the involvement and responsibility for

auxiliary works, incidental damages etc. during execution of
the original work. While writing the detailed specifications
the same order of sequence, as the work is to be carried out,
is maintained.

Engineering departments maintain detail specifications for

different items of work those are followed to carry out
works.
 
Standard Specifications :-
Detailed specifications for different works are drawn up by an
engineering department and printed to serve as a standard
guide to the department and also to refer it in the
specification part of a tender paper to avoid writing the
lengthy specifications.
Thus, standard specifications save valuable time, labour,
stationary expenditure and above all eliminates the scope of
deviations and mistakes during preparation of huge number of
tender papers through a Divisional Office.
Special Specification :-

Some items that are covered or works not well covered by the
departmental standard specifications, special specifications
for such items are drawn up by the Engineer-in-Charge,
approved and include in the tender paper under a heading
“Special Specifications”.
 
Open specifications or Manufacturers Specification :-
Open specification are specifications of products of
manufacturers which state both physical and chemical
properties and such other information of the product, but not
description of workmanship to be achieve during construction.
The physical properties specify mainly the strength, weight,
thickness or size and such other physical properties of the
product. The chemical properties specify mainly the
composition of chemical contents of the product and
precautionary measures if any required for storing the
product.
Advantages and disadvantages of open specifications :-
a) When procurements of materials are not restricted among a
few traders with their respective trade marks and any trader
can supply materials satisfying the open specifications,
progress of work does not suffer due to short supply of
materials.
b) Due to open specification materials can be procured at more
competitive rate.
c) Regional or local manufacturers can take the advantage to
manufacturers the material as a result the transportations
charge and delivery time may be reduced.
d) Due to open specifications , the quality of material is
standardized and, as a result, private parties the easily select
a material depending on its quality.
Disadvantage of open specifications :-
a) Frequent checking of materials of various manufacturers
becomes necessary. But checking of properties of materials is
done mainly from Govt. test laboratories. Due to heavy rush
from different manufacturers the result of test reports are
delayed. As a result procurement order to a new manufacturer
cannot be placed timely.
b) Due to limitations of open specifications interest for
further improvements of the quality of materials is hampered.
c) New manufacturers may receive the order offering very low
rates but after a short supply may fail to supply or maintain
the quality of materials throughout the supply period.
Restricted Specifications :- In restricted specification the
material for an item of work is described and the procurement
among some approved manufacturer or brands of the material
is restricted.
Thus the standard of materials such as for plumbing, painting ,
fitting., are assured to be of a certain degree of quality up to
the satisfaction of the Owner.
The materials of the approved manufacturers should be
equivalent in quality and more or less at per cost.
Example of an detailed Specification
Reinforced Cement Concrete (R.C.C.) :-

A) form work :- Form work shall include all forms or moulds required for
forming the concrete which is cast-in-situ, together with all temporary
construction required for their support.
1) Materials for Form work :- Form work shall be plywood, or steel
approved by the Engineer-in-Charge. Timber used for form work shall
be easily workable with nails without splitting and of light weight. It
shall be stiff and strong enough to avoid undue deflection when loaded
and not liable to warp when exposed to sun and rain or wetted casting
of concrete.
Form work shall be of rigid construction true to shape an dimensions
shown on drawings. It shall be strong enough to withstand the dead
and live loads and forces caused by ramming and vibrations of concrete
and other incidental loads imposed upon it during and after casting of
concrete. It shall be made sufficiently rigid by using adequate number
of braces and ties. To make up any settlement in the form work either
before or during the placing of concrete, hard wood wedges shall be
provided where required.
All form work shall be so constructed as to be removable in sections in the
desired sequence, without damaging the surface of concrete or disturbing
other sections. Forms should be easy to strip after connecting and no
price should be keyed into the concrete. The completed form work shall be
approved after inspection by the Engineer-in-Charge before the
reinforcement bars are placed in position.
2) Propping and Centering :- Props used for centering shall be of steel,
timber, posts, ballies or any other material approved by the Engineer-in-
Charge. In case when ballies are used none shall be less than 100mm in
diameter measured at mid length and 80mm at thin end. Ballies shall rest
on wooden sole plates of not less than 40 mm thickness having a minimum
bearing area of 0.1 square metre laid on ground or on 40 x 40 mm thick
brick masonry pillars in mud mortar of height not exceeding 40cm. All
props shall further be provided with double wedges between the sole
plates and the props so as to facilitate tightening and easing of shuttering
without causing shock to the concrete.
In case a span exceeds 4.50 metres and height exceeds 3.50
metres suitable horizontal as well as diagonal bracings shall be provided
after accounting for all forces including action of the wind which may
produce lateral forces. In case the height of centering exceeds 3.50
metres, the props may be provided in multi-stages. The detail of splicing
the props at each stage shall be as per approved drawing.
Before the casting of concrete is started, the props and wedges shall be
thoroughly checked to see that these are intact. While the casting of
concrete is an progress., at least one carpenter shall keep a constant watch
on the props and take immediate remedial measures, as soon as any of them
gets loosened.

b) Shuttering :- The shuttering shall be of approved dressed timber of

well seasoned wooden boards to give a smooth and even surface and the
joints shall not permit leakage of cement grout. The timber shall be free
from loose knots, projected nails, splits, adhering grout or other defects
that may mar the cement surface of concrete. It shall not be so green or
wet as to shrink after erection. Species of timber which are not affected
appreciably by its contact with water shall be used. When metal forms are
used, all bolts and nuts shall be countersunk and well ground to provide a
smooth plain surface. Opening for fan clamps and other fittings connected
with services shall be provided in the shuttering as directed by the
Engineer-in-Charge.
i) Surface treatment for shuttering :- The surfaces of timber shuttering
that would come in contact with concrete shall be thoroughly cleaned and
well wetted and coated with soap solution , raw linseed oil, or form oil of
approved manufacturer, or any other approved material such as polythene
sheets, to prevent adhesion of concrete to form work
The Engineer-in-Charge shall inspects and accept the form work as to its
strength, alignment and general fitness before placing any concrete in the
forms. But such inspection shall not relieve the contractor of his
responsibility fir safety of man, machinery, materials and for result
obtained.

ii) Camber :- Suitable camber shall be provided in horizontal members of

structures specially in long members to counteract the effects of
deflection. The camber for beams and slabs shall be 4 mm per metre i.e. I
in 250 and for cantilevers, at free end shall be 1/50th of the projected
length or as directed by the Engineer-in-Charge.

iii) Removal of Form Work :- The form work shall be removed avoiding
shock or vibration that may cause any damage to concrete. In a slab and
beam construction, sides of beam shall be stripped first; then the under
sides of slab and lastly the underside of the beam. The period that shall
elapse after the concrete has been laid before undertaking the work of
easing and removal roof centering and shuttering shall be as given below
according to IS 456-1978.
Parts of structure Where ordinary Portland cement is used
forms may be removed after expiry of the following periods :

1. Walls columns and vertical faces of 24 to 48 hours as may be decided by

all structural members the Engineer-in-Charge.
2.Slabs (props left under) 3 days
3. Beams soffit (props left under ) 7 days
4. Removal of props under slabs 7 days
a) Spanning up to 4.5m 7 days
b) Spanning over 4.5m 14 days
5. Removal of props under beams and arches :
a) Spanning up to 6 m 14 days
b) Spanning over 6m 2 days

In case cantilever slabs and beams, the centering shall remain till
structures for bearing down have been erected and have sufficient
strength.
c) Reinforcement :- Mild steel bars shall conform to the I.S.
specification, free from loose rust, dust, loose mill scales, coats of paints,
oil or other coatings which may destroy or reduce bond. It shall be stored
in such a way so as to avoid distortion and to prevent corrosion.
i) Bending of Overlapping :- Bars shall be bent cold, correctly an accurately
to the size and shape as shown on the detailed drawing or as directed by
the Engineer-in-Charge. Preferably bars of full length shall be used.
Overlapping of bars, where necessary, shall be done as directed by the
Engineer-in-Charge. The overlaps shall be staggered for different bars an
located at points, along the span, where neither shear nor bending moment
is maximum. Overlapping of bars can be kept apart by 25mm or 1 ¼ times
the maximum size of coarse aggregate whichever is greater, with concrete
between them. But where this cannot be done, the overlapping bars shall
be bound together at intervals not exceeding twice the diameter of such
bars, with two stands of annealed steel wire of 0.90 mm to 1.6 mm
thickness twisted tight. In case of mild steel the ends of rods shall be
bent in to semi-circular books, having clear diameter equal to four times
the diameter of bar, with a length beyond the bend equal to four times the
diameter of the bar. In case of deformed bars the books are not required.
Welding of bars shall be permitted in lieu of overlap if approve by the
Engineer-in-Charge.
ii) Placing in position :- Reinforcement bars shall be placed ion position as
shown in the drawings. Bars at their points of intersection shall be
securely tied together with two strands of annealed steel wire 0.90 to 1.6
mm thick twisted tight to make the skeleton of the steel work rigid so
that the reinforcement does not get displayed during the deposition o
concrete. Tack welding shall be permitted in lieu of binding with steel wire
if approved by the Engineer-in-charge.
The bars shall be kept in position by the following methods as the
case may be
For beam and slab construction , precast cover blocks in cement mortar 1:2
about 4 x 4 cm section and of thickness equal to the specified cover shall
be placed between the bars and shuttering, to avoid sagging and to
maintain requisite cover of concrete.
For cantilevered and double reinforced beams or slabs the vertical
distance between the horizontal bars shall be maintained by introducing
chain spacers or support bars of steel at 1.0 metre or at shorter spacing to
avoid sagging.
For columns and walls the vertical bars shall be kept in position by means
of timber templates with slots accurately cut in them; or with block of
cement mortar (1:2) suitably tied to the reinforcement.
d)Placing of Concrete :-a) Materials for concrete : Same as cement
concrete except the size of coarse aggregate shall be 20 mm unless
specially mentioned in the type of work.
i) Proportioning of concrete : Same as cement concrete
ii) Mixing : Concrete shall be mixed by mechanical mixer except or
small quantity when Engineer-in-Charge permits otherwise.
iii) Consistency or Workability :- The concrete, which will flow sluggishly
into the forms and around the reinforcement without any segregation of
coarse aggregate from the mortar shall be used. The consistency shall
depend on whether the concrete is vibrated or hand tamped. It shall be
determined by slump tests as per I.S. recommendation.
E ) Pouring of concrete :-Pouring into moulds. Placing of concrete shall
be commenced only after the Engineer –in-Charge has inspected the
centering, shuttering and reinforcement as placed and approved the same.
Shuttering shall be taken and free from all saw dust, pieces of wood or
other foreign material an shall be treated as prescribed ion surface
treatment for shuttering.
In case of casting of concrete o slabs and beams, wooden planks or cat-
walks supported directly on the centering by means of wooden blocks shall
be provided to convey the concrete to the place of deposition without
disturbing the reinforcement. Labourers shall not be allowed to walk over
the reinforcement.
In deep trenches and footings, concrete shall be placed through chutes as
Directed by the Engineer-in-Charge. In case of columns and walls, the
shuttering shall be so adjusted that the vertical drop of concrete is
not more than 1.5 metes at a time. During cold weather, with below 4.5 C.
temperature, laying of concrete shall not be done. During hot weather,
precaution shall be taken to see that the temperature of wet concrete
does not exceed 38 C. Unless permitted by the Engineer –in-Charge no
concrete shall be laid within half an hour of the closing time of the day.
The time between mixing and placing of concrete shall not exceed the
initial setting time of cement of 30 minutes.
F ) Compaction :- Concrete shall e compacted into a dense mass
immediately after placing by means if mechanical vibrators designed for
continuous operations during the whole period occupied for placing of
concrete. The vibrators shall be so adjusted that the center of vibrations
approximates to the center of the mass being compacted at the time of
placing. For certain items, such as roof slab, depending on the thickness of
the members and feasibility of vibrating the same, the Engineer-in-Charge
may permit hand compaction. Hand compaction shall be done with the help
of 16 mm dia steel tamping rod and tamping with wooden tampers so that
the concrete is thoroughly compacted and completely worked around the
reinforcement and into corners of the form work. The layers of concrete
shall be so placed that the bottom layer does not finally set before the top
Compaction shall be continued until the mortar fills the spaces between the
coarse aggregate and begins to cream up to form an even surface. Needle
Vibrators shall be withdrawn slowly so as to prevent formation of loose
pockets in the case of internal vibrators. The specific instructions of the
makers of the particular type of vibrator used, shall be strictly complied
with. Shaking of reinforcement for the purpose of compaction should be
avoided. Compaction shall be completed before the initial setting starts.
Over vibration or vibration of very wet mixes is harmful and shall be
avoided; under vibration is also harmful.

g) Construction Joints :- The position where construction joints are to be

made shall be as shown in structural drawing or as directed by the
Engineer-in-Charge. Such joints shall be kept to the minimum and shall be
located where the shear force is the minimum and these shall be straight
and at right angles to the direction of main reinforcement.
When stopping the concrete on a vertical plane in slabs and beams,
an approved, stop-board shall be placed with necessary slots reinforcement
bars or any other obstruction to pass the bars freely without bending. The
construction joints on a vertical plane shall be keyed. Inclined or feather
joints shall not be permitted.
Any concrete flowing through the joints of stop-board shall be removed
soon after the initial set. When concrete is stopped on a horizontal plane,
the surface shall be roughened and cleaned after the initial set. In case of
columns, the joints shall be horizontal and 10 to 5 cm below the bottom of
beam running into the column head. Concreting shall be carried out
continuously up to construction joints.
When the work has to be resumed, the joint shall be thoroughly cleaned
with wire brush and loose particles removed. A cost of neat cement slurry
at the rate of 2.75kg of cement per square meter shall then be applied on
the roughened surface before fresh concrete is laid.

h) Curing :- Same as cement concrete item no 15-24

i) Finishing :- In case of roof slabs the top surface shall be finished even
and smooth with wooden trowel, before the concrete begins to set.
Immediately on removal of forms, the R.C.C. work shall be examined by the
Engineer-in-Charge , before any defects are made good. The work that has
sagged or contains honeycombing to an extent detrimental to structural
safety or architectural concept shall be rejected. Surface defects of a
minor nature may be accepted and shall be made good as per direction of
the Engineer-in-Charge. The R.C.C. work shall be done carefully so that the
thickness of plaster required for finishing the surface is no more than
6mm.

J ) Testing Concrete :- Regular mandatory tests on the consistency and

workability of the fresh concrete shall be done to achieve the specified
compressive strength of concrete. Work tests and slump tests shall be
carried out as per standing practice. Three test specimens shall be made
from each sample for testing at 28 days.
 Analysis of rate

Purpose of rate analysis

To determine the current rate per unit of an item at the locality
To examine the viability of rates offered by contractors
To calculate the quality of materials and labour strength required for
project planning
To fix up labour contract rates

Fixing rate per unit of an item

Quantity of material and cost
Labour costs
Cost of equipments or tools and plants
Overhead or establishment charges
Profit
Quantity of materials and cost

Quantities of materials are those required per unit rate of work delivered
at work site and its cost include first cost, freight, transportation, sales
tax and insurance charges as arises in question.

In case when materials like cement and, steel, stone chips and bitumen are
supplied departmentally then profit on the cost of materials are not
allowed, but cost of carriage from godown to work site shall be added.

Labour costs
To obtain labour costs the number and wages of different categories of
labourers, skilled and unskilled namely mason, mazdoor etc required for
each unit of work should be known and this number is to be multiplied by
the respective wage per day.
Cost of equipments , tools and plants

Wherever possible the cost of equipments and ordinary T and P those

required for general use should be allocated to specific item of rate.

For example the cost of operating a concrete mixer should be spread over
those items of rate for which it is used.

For certain tools and plants it is difficult to allocate their use to an

individual item of rates and it is therefore suggested to add costs in such
cases of expenditure to overhead ie establishment charges.

Special tools and plants

For big projects it becomes necessary to use special type of tools and
plants ie special type of concrete mixing machines like batching plants and
special type of mixed concrete transport vehicle named tripping wagon or
dumper, cranes etc in use.
In order to purchase such types of special equipments an amount 1 to 11/2
% of the estimated cost is provided in the estimate
Overhead or establishment charges;

This includes such items as office rent and depreciation of its equipment ,
salaries of office staff, postage , lighting, traveling, telephone account,
plan and specifications etc.

Small tools, planks, ladders, ropes and such hand tools as the contractor
provides for his workman should also be included in the overhead charge as
suggested in cost of equipments.

This is usually 21/2% of the net cost of a unit rate and may rise up to 5 %.
Overhead charge increases if the progress of a project is delayed.

Overhead charges may be divided under two categories:

A )General overheads and B) Job overheads

General overheads

Salaries of office staff

Purchase of stationery articles, printings, postages, repairs etc
Office rent
Telephone and electric bills
Traveling etc and all such expenses required to the run the office.

General overhead is a recurring known expenditure and does not depend on

the volume of work under execution.

This account is spread proportionately on all work in a year.

A construction firm has to bear such expenditure even though there is no

work in hand. For a big firm general overhead is high.

On the other hand small firms require nominal general overhead.

Any amount for such expenses cannot be recovered from the work.
Volumes of work can be executed with proportionally low general overhead
establishment.
Job overhead

Salaries of all personnel ( technical or non technical) engaged for the work
Temporary sheds or house and godowns rents for the work
Small tools, planks, ladders, ropes and hand tools as the contractor
provides for his workmen
Repairs and depreciation for tools and plant
Lighting at site
Mobilisation of establishments, tools and plant
Public relations
Labour welfare and safety measures
Workmen’s compensation, insurance etc
Interest on investment
Theft or loss etc.

Job overhead is not a known expense, depends on the volume of work under
execution.
When there be no work no expense is required. In case there be idle labour
or maintenance due to owners fault recovery of expenses for such part of
job overhead becomes possible
Profit

Generally a profit of 10% should be considered reasonable for ordinary

contracts after allocating all charges of establishments. Equipments etc.
Fro small jobs 15% profit and for large jobs 8% profit should be
considered as reasonable.

Water Charges:
For drinking purpose of the workers and for the work, arrangement of
water either by sinking tube well or by taking temporary water connection
from the corporation or Municipality becomes necessary.

In order to meet up the expenses an amount 1% of the total cost of

materials and labour has been provided in the analysis of Rate as per
provision made in the standard analysis of rates.
Factors effecting Rate analysis

Specifications of the item which indicates the quality and proportion of

materials, the method of construction and protection of works

The present rate of materials for the item of work up to the work site

Daily wages of different categories of labourers at the locality with their

respective outputs

The range of lead and lift required for deposition of materials to carry out
the item of work

Percentage charge for overheads which includes insurance and the

possibility of theft or loss

The range of profit and availability of water in connection with the

construction work.

Besides these the site condition, site organisation and cost control during
execution etc should be considered as these factors affect the cost per
unit of work done at site.
Description Unit Qty Rate Cost
Remarks
Cement Concrete
1:1:2 ( 1 cement: 1 coarse Sand: 2 graded stone
aggregate of 20 mm nominal size)
Materials :
Stone aggregates 20mm Cum 0.675 290 Rs196/-
Stone aggregates 12mm Cum 0.225 290 Rs 65/-
Generally one part of 12 mm graded aggregate is mixed
to 3 parts of 20 mm graded aggregate. However, it
should be as per the direction of Engg- in- charge.
Cement q 6.1 460 Rs 2806/-
Coarse Sand Cum 0.45 530 Rs239/-
Carriage:
Coarse sand
Stone aggregate Cum 0.45 350 Rs 158/-
Cement Cum 0.90 190 Rs171/-
Labour: t 0.61 60 Rs 37/-
Foreman
Each 0.05 250 Rs 13/-
Beldar (M)
Each 0.70 120 Rs 84/-
Coolie (F)
Each 0.70 90 Rs 63/-
Mason
Each 0.125 250 Rs 32/-
Waterman
Each 0.125 120 Rs 15/-
Add cost of hire & running charges of mixer, vibrator,
Rs45/-
water pump etc, @ 1.15%
Rs 116/-
Add for Sundries & Contingencies @ 3%
Rs 58/-
Add for Water Charges & Electricity @ 1.5 %
Rs 582/-
Add for Oh & CP @ 15%
Rs132/-
VAT 4%
Cost of 1 cum Cement Concrete
Rs 4812/-
Rate per cum
Description Unit Qty Rate Cost

Cement Concrete
1:2:4 ( 1 cement: 2 coarse Sand: 4 graded stone
aggregate of 20 mm nominal size)
Materials :
Stone aggregates 20mm Cum 0.705 290 204/-
Stone aggregates 12mm Cum 0.235 290 68/-
Cement q 3.2 460 1472/-
Coarse Sand Cum 0.47 530 25/-
Carriage:
Coarse sand Cum 0.47 350 165/-
Coarse aggregate Cum 0.94 190 178/-
Cement t 0.32 60 19/-
Labour:
Foreman Each 0.05 250 12/-
Beldar (M) Each 0.70 120 84/-
Coolie (F) Each 0.70 90 63/-
Mason Each 0.125 250 31/-
Waterman Each 0.125 120 15/-

Add cost of machinery etc @ 1.75% 40/-

Add for Sundries & Contingencies @ 3% 70/-
Add for Water Charges & Electricity @ 1.5 % 35/-
Add for Oh & CP @ 15% 350/-
VAT 4% 70/-
Cost of 1 cum Cement Concrete Rs 2900/-
Description Unit Qty Rate Cost

Cement Concrete
1:2:4 ( 1 cement: 2 coarse Sand: 4 graded stone
aggregate of 40 mm nominal size)
Materials :
Stone aggregates 40mm Cum 0.544 290 157/-
Stone aggregates 20mm Cum 0.241 290 70/-
Stone aggregates 12mm Cum 0.126 290 36/-
Cement q 3.2 460 1472/-
Coarse Sand Cum 0.47 530 249/-
Carriage:
Coarse sand Cum 0.47 350 164/-
Stone aggregates 40mm Cum 0.544 190 103/-
Stone aggregates 20mm & 12mm Cum 0.367 190 70/-
Cement t 0.32 60 19/-
Labour:
Foreman Each 0.08 250 20/-
Beldar (M) Each 0.80 120 96/-
Coolie (F) Each 0.80 90 72/-
Mason Each 0.125 250 31/-
Waterman Each 0.125 120 15/-
Add cost of machinery etc @ 1.75% 45/-
Add for Sundries & Contingencies @ 3% 77/-
Add for Water Charges & Electricity @ 1.5 % 38/-
Add for Oh & CP @ 15% 380/-
VAT 4% 80/-
Cost estimation
A cost estimate establishes the base line of the project cost at different
stages of development of the project.

A cost estimate at a given stage of project development represents a

prediction provided by the cost engineer or estimator on the basis of
available data.

Cost estimation is also necessary to evaluate profit measures and

survivability.

For construction industry cost estimation becomes even more important

due to its being a long time process and estimating cost over a time
includes other temporal factors also.
The capital cost for a construction project includes the expenses related to
the initial establishment of the facility:

1. Land acquisition, including assembly, holding and improvement

2. Planning and feasibility studies

3. Architectural and engineering design

4. Construction, including materials, equipment and labor

5. Field supervision of construction

6. Construction financing

7. Insurance and taxes during construction

8. Owner's general office overhead

9. Equipment and furnishings not included in construction

10. Inspection and testing

The operation and maintenance cost in subsequent years over the project life
cycle includes the following expenses:

1. Land rent, if applicable

2. Operating staff

3. Labor and material for maintenance and repairs

4. Periodic renovations

5. Insurance and taxes

6. Financing costs

7. Utilities

8. Owner's other expenses

The magnitude of each of these cost components depends on the nature, size and
location of the project as well as the management organization, among many
considerations. The owner is interested in achieving the lowest possible overall
project cost that is consistent with its investment objectives.
In cost estimation for construction companies they include allowance for
contingencies or unexpected costs occurring during construction. According to
past trends company may have costs components for the following in estimate:
-

1. Design development changes,

2. Schedule adjustments,

3. General administration changes (such as wage rates),

4. Differing site conditions for those expected, and

5. Third party requirements imposed during construction, such as new permits.

All cost estimation is performed according to one or some combination of the
following basic approaches: -

Production function
In construction, the production function may be expressed by the relationship
between the volume of construction and a factor of production such as labor or
capital.
A production function relates the amount or volume of output to the various inputs
of labor, material and equipment.

For example, the amount of output Q may be derived as a function of various

input factors x1, x2, ..., xn by means of mathematical and/or statistical
methods.
Thus, for a specified level of output, we may attempt to find a set of values
for the input factors so as to minimize the production cost.

The relationship between the size of a building project (expressed in square

feet) to the input labor (expressed in labor hours per square foot) is an
example of a production function for construction.
Empirical cost inference

Empirical estimation of cost functions requires statistical techniques which relate

the cost of constructing or operating a facility to a few important characteristics
or attributes of the system.

The role of statistical inference is to estimate the best parameter values or

constants in an assumed cost function.

Usually, this is accomplished by means of regression analysis techniques.

Unit costs for bill of quantities

A unit cost is assigned to each of the facility components or tasks as represented

by the bill of quantities.

The total cost is the summation of the products of the quantities multiplied by the
corresponding unit costs.

The unit cost method is straightforward in principle but quite laborious in

application.

The initial step is to break down or disaggregate a process into a number of tasks.

Collectively, these tasks must be completed for the construction of a facility.

Once these tasks are defined and quantities representing these tasks are
assessed, a unit cost is assigned to each and then the total cost is determined by
summing the costs incurred in each task.

The level of detail in decomposing into tasks will vary considerably from one
estimate to another.
Allocation of joint costs

Allocations of cost from existing accounts may be used to develop a cost function
of an operation.

The basic idea in this method is that each expenditure item can be assigned to
particular characteristics of the operation.

Ideally, the allocation of joint costs should be causally related to the category of
basic costs in an allocation process.

In many instances, however, a causal relationship between the allocation factor and
the cost item cannot be identified or may not exist.

For example, in construction projects, the accounts

for basic costs may be classified according to (1) labor, (2) material, (3)
construction equipment, (4) construction supervision, and (5) general office
overhead. These basic costs may then be allocated proportionally to various tasks
which are subdivisions of a project.