Unit I & II

Estimating and Costing
Def: The process of determination of quantities of items of work and its cost for completion
1.       Construction Activities
a.       Plans
                                                               i.      Plans
                                                             ii.      Elevations
                                                            iii.      Sections
b.      Estimating and Costing
                                                               i.      To calculate the quantities of various items of work
                                                             ii.      To calculate the cost of structure
c.       Execution (Construction)
2.       Requirements to prepare an estimate
a.       Drawings
b.      Specifications
                                                               i.      Properties of materials
                                                             ii.      Mix Proportions
                                                            iii.      Workmanship
                                                           iv.      Source of materials and Conveyance
c.       Rates
                                                               i.      Standard Schedule of Rates (SSR) – approved by the concerned engineering authorities every year
                                                             ii.      Local market rates for the items which are not covered in SSR
                                                            iii.      Rate per unit work of various items of work can be worked out by the Method of Analysis or Analysis of Rates using
1.       Standard Data
2.       Lead Rates from SSR
3.       Types of Estimates
a.       Approximate Estimate or Rough Estimate as per Practical Experience
b.      Detailed Estimate as per Drawings

S No
Description of work
No’s
L
B
D/H
Quantity
Total Quantity

c.       Abstract Estimate – it gives accurate cost of the project
S No
Description of work
Quantity
Rate
Per
Amount
Remarks

4.       Accuracy in Estimation
a.       All measurements shall be measured to the nearest 0.01m
b.      All the areas shall be worked out the nearest 0.01 Sq.m
c.       All the volumes shall be worked out the nearest 0.01 Cum

5.       Types of Specifications
a.       General Specification (Brief Specification)
b.      Detailed Specification
6.       Lump sum Items which are not possible to workout in details
a.       Electrification @ 8 to 10%
b.      Water supply and Sanitary works @ 8 to 10%
c.       Contingencies and unforeseen items
7.       P S Charges @ 2.5% – Salaries of Supervisors (Temporary Staff)
a.       Works Inspector
b.      Work Assistants
c.       Technical Masteries
d.      Watchmen etc.,
8.       Units of Measurement of various items of work
9.       Main Items of work (Buildings)
a.       Earthwork Excavation
                                                               i.      All types of soils except rock
                                                             ii.      Rock cutting
                                                            iii.      Pipeline trench
                                                           iv.      Road Formations
1.       Cutting
2.       Embankment
b.      Refilling of Foundations
c.       Concrete Foundations
                                                               i.      Plain Cement Concrete (PCC 1:4:8 or 1:5:10) using 40mm HB Metal
                                                             ii.      Reinforced Cement Concrete (RCC)
1.       Footings
2.       Foundations
d.      Masonry
                                                               i.      Stone Masonry for Foundation
                                                             ii.      Brick Masonry for Superstructure and Parapet Walls
e.      RCC works
                                                               i.      Columns
                                                             ii.      Plinth Beam
                                                            iii.      Lintels and Sunshade
                                                           iv.      Roof Beams
                                                             v.      Roof Slab
                                                           vi.      Staircase & Lifts
f.        Flooring
                                                               i.      Cement Flooring
                                                             ii.      Cuddapah Slabs
                                                            iii.      Marble
                                                           iv.      Granite
                                                             v.      Vitreous Tiles
g.       Roofing
                                                               i.      RCC Slab
                                                             ii.      AC Sheet
                                                            iii.      GI Sheet
                                                           iv.      PVC Roofing
h.      Plastering for
                                                               i.      Concrete works – 12mm thick
                                                             ii.      Stone Masonry – 20mm thick
                                                            iii.      Brick Masonry – 12mm thick
i.         Pointing for Stone Masonry
j.        Doors (1.0 x 2.0m) and Windows (0.9 x 1.2m)
k.       White Washing, Color Washing and Distempering
l.         Painting – Coefficients for
                                                               i.      Door Paneled – 2.25 times
                                                             ii.      Window Paneled – 2.75 times
                                                            iii.      Cup Board – 2.25 times
                                                           iv.      Glazed Door or Window – 1 time
                                                             v.      Flush Door – 2 times
m.    Steel Reinforcement for
                                                               i.      Lintels @ 120 kg/cum
                                                             ii.      Sunshade @ 10 kg/Rmt
                                                            iii.      Roof Columns @ 160 kg/Cum
                                                           iv.      Roof Beams @ 160 kg/Cum
                                                             v.      Roof Slab @ 80 kg/Cum
10.   Methods of Taking out Quantities
a.       Center line method
b.      Long wall Short wall method