Specification and Cost Estimation of Building

Basics of Cost Estimation

1. Course Title :
Specification and Cost Estimation
Khulna University of Engineering & Technology
Presented By
Dr. Md. Julfikar Hossain
Superintendent Engineer, Engineering Office, KUET
and
Atique Ahammad Zawad
Department of Architecture, KUET
Course No : Arch 3212
Credits:1.5 , Contact hours: 3 hrs/week

2.  
References Books:
Time Sever Standards for Building Type
4
th
Edition, McGraw Hills, USA.
By Chira Joseph D, Crosbie J Michael
Form, Space and Order
3
rd
Edition, McGraw Hills, USA
by Ching D.K Architecture

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3. Suggested References :
Estimating, Costing and Specification.
By Rangwala, S.C., Rangwala, K. S.,
Estimating, and Specification.
By Namabati, and Roushan
Estimating
By Chakravarty, S.,
PWD Schedule of Rates
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4. Course Content:
Drawing and Specifications relationship
Specification Language
Sections
Paragraphs
Specification of Material-scope
Method
Method of construction/application
Market survey
Cost analysis
Preparation of Schedule and BOQ rules
Regulations
Obligations and preparation of tender document.
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5. Drawing and Specifications relationship
Drawing:
Drawing means the art or technique of representing an object or
outlining a figure, plan, or sketch by means of lines
Specifications:
Specification means a detailed description of work to be done
or
materials to be used in a project : an instruction that says
exactly how to do or make something
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6. Drawing and Specifications relationship
The drawings of a structure will show the properties and relative
positions of its various parts. It is not possible to furnish the
data regarding the quality of materials and workmanship on the
drawings due to shortage of space. Hence, this information
regarding the quality of materials and workmanship is conveyed
in a separate contract document which is known as the
specifications for the work.
Define Complete Structure
Drawings + Specifications
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7. Objective of the Specifications
1.The specifications define the quality of materials and
workmanship.
2.The information and instructions contained in the
specifications ( For Contractor and supervising staff)
3.The main object of the specification is to state the information
which the engineer wants to convey so as to fulfil the needs of
his design.
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8. Importance of Specifications
Drawings and Specifications forms two important contact
documents.
Use of Specifications
For the proper construction the specifications serves the
best guide to the contractor and his sub-contractors, material
suppliers and architect’s or owner’s site supervisors.
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9. Types of Specifications
1. Brief Specifications
2. Detailed Specifications
1. Brief Specifications
While preparing the estimate, the quantity surveyor writes down
the brief description of every item.
2. Detailed Specifications
The detaild specifications form a pert of the contract document.
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10. 2. Detailed Specifications
a. General provisions
-Conditions of contract
b. Technical provisions (3 Types)
-The technical provision contain detail instructionsregarding
the desired quality of the final product.( Exm. Material test)
c. Standard Specifications
-Specifications are seldom written completely for all items of
the work. Standardise specification for most of the items
according in works of similar nature.
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11. b. Technical provisions
1. Specifications for materials and workmanship
i. For materials
1. Physical properties
2. Chemical properties
3. Electrical, thermal and acoustical properties
4. Appearence of the material
5. Protrection information (transport, handling, storage)
6. inspection and test of material
ii. For workmanship
1. practical limits of tolerance
2. Construction method
3. protection of the finished work
2. Specifications for performance
3. Specifications for proprietory commodities.
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12. c. Standard Specifications
-Specifications are seldom written completely for all items of the
work. Standardise specification for most of the items according in
works of similar nature.
Following points for Standard Specificatons:
1. Extreme care to the particular work to be executed.
2. For variable requirements
3. Same specification for the next job of similer nature.
4. Prepared by government or manufactures of materials or
professional bodies.
5. It should be periodically revisedto include changes in technique.
6. Every city has got its own building codes which has assumed the
shape of standard specifications for a particular locality.
7. Advantages of standard specifications are manifold. (Simplified
and costs are reduced for manufactures of materials)
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13. c. Standard Specifications
-Specifications are seldom written completely for all items of the
work. Standardise specification for most of the items according in
works of similar nature.
Following points for Standard Specificatons:
1. Extreme care to the particular work to be executed.
2. For variable requirements
3. Same specification for the next job of similer nature.
4. Prepared by government or manufactures of materials or
professional bodies.
5. It should be periodically revisedto include changes in technique.
6. Every city has got its own building codes which has assumed the
shape of standard specifications for a particular locality.
7. Advantages of standard specifications are manifold. (Simplified
and costs are reduced for manufactures of materials)
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14. Classification of Specifications
1. Open specification
( Adv.-for description of basic materials, Cement, sand, etc. Dis. Adv.-
Time consume for testing and spent valuable time in framing them)
2. Restricted Specification
( Adv.-it promotes competition among the manufacturers. Dis. Adv.-
various products mentioned in the approved list should be carefully
considered. Problems of design and quality product)
3. Closed specifications.
( Adv.-Completion of drawing and choice of owner. Dis. Adv.-product
company or trademark or country are specified)
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15. Design Specifications
A specification, if it has to serve its purpose
adequately should be designed rather than simply
written or copied.
Some of the important aspects of the design of a
specification are mrentioned below:
1. Changes:
2. Clearness:
3. Co-operation:
4. Cost:
5. Designer
6. Flexibility:
7. Product control: 15
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16. Specification Language
A specification often refers to a set of documented requirements
to be satisfied by a material, design, product, or service.
Essential principles of good specification writing:
1.
Subject matter
2.
Grammer
3.
Abbreviations
4.
Development of style
5.
Selection of words
6.
Accuracy
7.
Conflicting requirements
8.
Practical limits and commercial sizes
9.
Clearness
10.
Fairness

11.Brevity or Concise

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17. Source of information
Source of information for good specification writing:
1.
Contract Drawing
2.
Previous specification
3.
Requirements of owner
4.
Site investigation
5.
Standard Specifications
6.
Trade Catalogues
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18. Submission of the fallowing items specification :
1. Earth Excavation
2. 250 mm thick Brick work (1:6)
3. RCC work (1:1.5:3)
4. Painting in three Coats
5. 18mm thick marble finished
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19. THANK YOU
EVERYONE