University of Sulaimani
College of Engineering
Civil Engineering Department
Third Year
Prepared by:
Niyan A. Hamid
Assist. Lecturer
niyan.hamid@univsul.edu.iq
2021-2022
ESTIMATION AND CONSTRUCTION METHODS
UNIT 1: THE CONSTRUCTION INDUSTRY
1.1
Construction Industry
The construction industry is essentially a service industry whose responsibility is to convert plans and
specifications into a finished project.
The construction industry (including design, new and renovation construction, the manufacture and supply
of building materials and equipment) is one of the largest industries. The increasing rate of technological
development and growing international competition in the industry are serving to accelerate the
development of new construction methods, equipment, materials and management techniques.
1.2
Construction industry divisions
Constructing any project includes many steps and relations among owners, engineers, contractors,
companies, factories, materials and equipment providers, workers and others.
The engineer should be aware of various methods of construction and their costs to be able to perform the
work with least cost. He should take into consideration the different methods that the project can be done
and the equipment which are going to be used.
Industry Sectors:
There are five basic sectors of the industry:
1- Residential Building
Residential construction addresses the housing needs of a society. Housing construction takes many
forms: individual homes, apartments (flats), townhouses and prefabricated units.
2- Commercial Building
This sector addresses the needs of commerce, trade and government. This is the category that
includes banks, schools, office buildings, hotels, shopping malls, religious facilities, stadiums,
theatres, universities, hospitals, government buildings, and other facilities where people gather.
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UNIT 1: THE CONSTRUCTION INDUSTRY
3- Heavy Civil Construction
This sector of the industry is referred to as horizontal construction, the heavy civil sector includes
roadways, bridges, tunnels, dams, airports, railways, and any work associated with infrastructure
and transportation.
4- Industrial Construction
This sector is highly specialized and requires firms with vast resources and significant construction
and engineering expertise. Manufacturing plants, electrical generating facilities, oil refineries,
pipelines, steel mills, and chemical processing plants are all examples of industrial construction
projects.
5- Environmental Construction
Generally, environmental construction comprised of projects that improve the environment,
maintain public health, and contribute to a community’s quality of life.
Each sector is characterized by different means, methods, and materials of construction. Each sector
requires specific expertise and familiarity in order to optimize the construction operations and management
efforts.
1.3
Project Cycle Life
The total processes of engineered construction may be thought of as consisting of six major elements:

Project definition (Needs and initial concept)

Preliminary planning (Determining the technical and financial feasibility of the project)

Project design (Preparation plans, specifications and cost estimates)

Project construction (Carrying out the work)

Closure
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ESTIMATION AND CONSTRUCTION METHODS
Figure 1- 1 Project Life Cycle
1.4
Project Cost
The cost of any project is a very important factor and can be divided into:
a) Material cost
b) Labour cost
c) Machine and equipment cost
d) Engineering supervision cost
e) Profits
1.5
Construction Economy
There are some ways to increase productivity and minimize project costs during construction include:
1. Good work planning
2. Carefully selecting and training workers and managers
3. Efficiently scheduling labour, materials and equipment
4. Using laboursaving techniques such as prefabrication and preassembly
5. Minimizing rework through timely quality control
6. Preventing accident through good safety procedures
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UNIT 1: THE CONSTRUCTION INDUSTRY
1.6
Elements of Construction Management
Skilful in construction management resulted in construction completion on time and within budget. Poor
construction management practices, on the other hand, often result in one or more of the followings:
1. Project delays that increase labour and equipment cost
2. High material cost cause by poor purchasing procedures
3. Increased subcontractor cost and poor contractor-subcontractor relations
4. High insurance costs resulted from poor safety records
5. Low profit margin
1.7
Construction Activities
Most construction projects are divided into specific activities of work, each with a specific objective and
length of time to accomplish. Each activity generally has a specific beginning and ending point and may
require a specific trade classification.
As an example, the construction of a reinforced concrete retaining wall can be divided into the following
activities:
1- Layout (planning) of the site
2- Excavating of earth mechanically
3- Building and erecting of forms
4- Erection of reinforcing steel
5- Pouring (Casting) of concrete
6- Curing of the concrete
7- Removing of forms
8- Finishing the concrete surface
9- Clean-up of the site
The following steps should be followed before commencing the work program:
 Preparing a list of the project activities.
 Estimating the time required to complete each activity.
 Specifying the time of performing each activity and the sequence of the activities.
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ESTIMATION AND CONSTRUCTION METHODS
1.8
Site Planning
Job Layout
One of the first duties of the supervisor engineer is to prepare a job layout for the project. Job (site) layout
can be defined as site space allocation for material storage, working areas, units of accommodation, plant
locations, general circulation areas and as well as entry and exit gates for deliveries and emergency services.
It is a scaled drawing of the proposed construction site showing all the previously mentioned features.
The following points should be considered in preparing a good site layout:
1. Arrange all areas to reduce the time consumed in carrying materials from storage areas to the project.
2. Materials that are similar in use should be stored, close together, where possible. In material
handling and storage, little things can make a big difference. For example, you should always make
sure that delivered materials are unloaded and stacked with the materials to be used first on top of
the pile.
3. Easy accessibility will make the equipment and vehicle drivers more confident, minimize the chance
of accidents, and save time in manoeuvring to arrive at and leave the project.
4. The general warehouse should be near the entrance in order to facilitate the delivery of materials to
be stored in the warehouse.
5. Providing protected walkways to protect pedestrian from unexpected accidents.
6. Many constructions work require the use of cranes on site to lift and transfer very heavy objects
around the site. These cranes may require a fixed location on site.
The figure shown below illustrates a job layout for a multistorey reinforced concrete frame building.
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UNIT 1: THE CONSTRUCTION INDUSTRY
Figure 1- 2 Site Layout
1.9
Work Breakdown Structure (WBS)
A key part of a good construction project is the work breakdown structure (WBS). WBS is a hierarchical
decomposition of the total scope of work to be carried out by the project team to achieve the project
objectives. The WBS organizes and defines the total scope of the project, and represents the work specified
in the current approved project scope statement.
In other words, WBS is the process of subdividing project works into smaller, more manageable
components.
The key benefits of WBS:
1. Provides a structured vision of what has to be supplied, transport and produced.
2. Specifies the work task for every crew member, subcontractor, and consulting engineer working on
the project.
3. To organize activities into manageable components that will be achieve project objectives.
4. Helps in organizing what needs to be done in small packages of activities, where work is scheduled,
estimated, monitored and controlled.
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ESTIMATION AND CONSTRUCTION METHODS
Figure 1- 3 WBS Example
1.10 Project Control
Once the process of construction started, controlling the progress of construction is important. The project
must be monitored from beginning to end to ensure that all of the following targets are met.
Time
Cost
Quality
Project control requires continuous monitoring and evaluation of actual performance relative to the
estimated performance for all aspects of the works that have an impact on cost, time and quality.
1. Quality Control
The plans and specifications are the primary tools used to verify project quality. The best way to track
quality performance on a project is to prepare and implement a complete quality plan.
There are some points that should be considered for Quality Control Inspection Program
1. Organization and Staffs Responsibilities

Responsibilities of various organizations

Number of staff and required availability

Lines of communication and authority
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UNIT 1: THE CONSTRUCTION INDUSTRY
2. Inspection Plan and Field Practices

Knowledge of contract plans and specifications

Inspection equipment and resources

Coordination with contractor's schedule
3. Documentation

Daily inspection and non-conformance reports
4. Material Testing

Testing schedule and standards

Adequacy of on-site and off-site laboratory

Evaluation of testing data and actions required
2. Controlling Cost
The original estimate used for bidding purposes is converted to a project budget and establishes the
benchmark from which project costs are monitored. During this conversion process, which usually takes
place right after the contract award, quoted prices are confirmed with purchase orders and subcontracts.
Sometimes there are minor adjustments made in the budget because of price fluctuations between the time
when the job was bid and when the work begins, but generally the budget contains the same work packages
developed in the estimate.
3. Time Control
Time controlling is done through scheduling which is a time phased plan Schedules are used as guides
during the performance of an operation in order to control the pace of activities and to permit completion
of the operation at the desired or required time. There are a number of different forms of schedules that may
be used, including the Bar Chart.
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