ARBA MINCH UNIVERSITY

INSTITUTE OF TECHNOLOGY
DEPARTMENT OF CIVIL ENGINEERING
Course outline
Course Title:- Contract, Specification and Quantity survey (CEng5202) Credit hours: 3
Target Group: G5C-(Section D, E & F) Instructor: Kassahun A. (Msc)
Academic Year: 2014/15 Semester: I

I. Course Content:

Chapter 1: Procurement and Contract

1.1. General Introduction
1.2. Stages in Construction
1.3. Introduction to Procurement
1.4. Procurement and Contract Management
1.5. Procurement and Contract Delivery Methods
1.6. Procurement Management

Chapter 2: Construction Contract

2.1. Principles of Contract Law
2.2. Types of Construction Contract
2.3. Contract Documents
2.4. Contract Management:
• Contract Administration and Closing
• Claims and Dispute Management

Chapter 3: Specification
3.1. Introduction
3.2. Purposes of specifications
3.3. Types of Specifications
3.4. Specification writing

Chapter 4: Quantity surveying

4.1. Introduction
4.2. Measurement of civil works
4.3. Basic principles in taking off
4.4. Technical specification and method of measurements for the different trade of
works

Chapter 5: Project Cost Estimation & Valuation

5.1. Project cost estimation
5.2. Types of costing or estimation
5.3. Project valuation

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 0

 II. References:

 Estimating and Costing in Civil Engineering Theory and Practice Dutte B.N
New Delhi 2002
 Writing Specification for Construction Cox Peters London 1994
 Estimating Construction Costs, 5th Edition Peurifoy RobertlBoston 2002
 John Adriaanse, Construction Contract Law, Palgrave Macmillan, 2 004
 Ivor H. Seeley, George P. Murray, Civil Engineering Quantities, Palgrave
Macmillan, 2001
 R.W. Thomas, Construction Contract Claims, Palgrave Macmillan, 2001
 FIDIC Conditions of Contract for works of Civil Engineering Constructions,1991
 BATCODA Conditions of Contract, 1991
 Duncan Cartlidge, New Aspects of Quantity Surveying Practice, Butterworth-
Heinemann; 2nd edition, 2006

III. Evaluation:

 Attendance: 10%
 Mini project : 40%
 Final Examination: 50%

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 1

 CHAPTER 1

PROCUREMENT AND CONTRACT

1.1 INTRODUCTION

Construction is an important industry by which societies create most of new values. Most
of mankind‟s economic, social, political, environmental, public reforms and day-to-day
activities are dependent on the infrastructure delivered by the construction industry.

The Construction Industry can be categorized into three major sectors; namely, Transport
and Communication (Road, Railway, Airway, and Telecommunication related physical
works); Water Works and Energy; and Buildings and Other Physical Infrastructures.
Accordingly, their capital budget requirements vary extensively depending on the focus
the economic trend requires for the nation development.

The construction industry is at the same time regarded as both a profession and business.
It is a profession that it works for an improved service. It is a composition of multi-
disciplinary experts all geared towards a specific objectives. The construction industry is
at the same time a business that it works for a fair and reasonable profit.

The goals and objectives of the construction industry depend upon the entity. Goals are
the ultimate targets having relevance to needs of society, individual or enterprise.
Objectives are quantitative and/or qualitative elements that brings about the
predetermined goals. The goal of a road project might be to improve accessibility
between two junctions while its objectives are building the gravel road, culverts, drainage
etc. A client, be it a government body, a public or private agency undertakes development
facilities such as housing, roads, power plants with certain motives or long term aims. A
corporate body (Engineering consulting firms or Contractors) may aim at making profit
and meeting growth needs of organization, diversifying corporate activities, engaging idle
resources, staying in business etc to meet the predefined corporate and business level
strategies. However as viewed form planners and economists, the construction industry is
evaluated based on the benefits and contribution it would offer to the society with respect
to the development and growth strategies to be achieved in a national level.

The main players in the construction industry are:

 The Client: The client is the initiator and owner of the project
 The Consultant: The consultant transfers the wish of the owner into
realizable form and makes the study, design and possibly the
supervision.
 The Contractor: The contractor is the one who performs the work.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 2

  Insurance Companies: A Contractor is required to provide bid bonds as
a condition of being allowed to bid, and then they must provide
insurance for Performance bonds and payment bond prior to award of
the contract. Insurance companies provide bid bonds, performance and
payment bonds, and they also service the liability and property insurance
needs of contractors.
 Banks: Banks provide the working capital contractors need to build the
project. Banks also provide bonds for bid and performance.
 Suppliers: The quality of a construction project is very dependent on the
quality of the suppliers used by individual contractors.
 Permitting Agencies: represent the interests of public safety. They
administer publicly funded construction projects, and they ensure private
construction projects comply with zoning laws and building codes.
 Public: The public is impacted by every construction activity. Impacts
are both good and bad.

In our country Ethiopia there are different problems in the construction industry that‟s
why the industry is not effective as it should be. These problems may be related with
costs, qualities of material and workmanship, management systems. In general the
following problems are the main problems in Ethiopia.
 cost over run
 Delay of projects
 Serious disputes and claims in projects
 Terminations of projects
 Dissatisfaction of clients
 Inefficient resources management
 Incompetence of local contractors
 Inefficient contract administration
 High demand of infrastructures
 roads, bridges
 buildings
 dams
 A clear demand for the industry to do its business in a professional manner

1.2 Stages in Construction

1.2.1 Pre-design stage
At this stage the owner puts his visions and wishes and with this as the starting point,
the various groups (professionals) try to conceptualize the project and prepare a
conceptual design. At this stage the owner will heirs a consultant to formally
design and develop the concept into a practicable project and the following things

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 3

 will be conducted in this stage.
 Selection of suitable site,
 Preparation of tentative cost estimate,
 Project appraisal and selection of designer.
 Making topography of the site and preliminary soil investigations.
 Budget Request
 Bidding Documents preparation for Services
 Selection of Consulting Firm

1.2.2 Planning and design stage

Planning is a function of devising the cause for future with a vision, formulated for
the future state of the organization or project. At this stage the consultant plans and
designs the project based on the owner‟s requirement and the possible constraints.
The designs are conceptual, preliminary and final drawings are drawn by the
consultant. The project will be checked in this stage and the documents which are
used for the tendering purpose should also be prepared. Finally the detailed cost
estimate will be prepared.

1.2.3 Tendering, evaluation and award stage

At this stage contractors are invited to offer their best technical and financial
offers as per the conditions and specifications depicted in the contract documents.
Usually a 2% of bid bond is required so as not let him disappear.

The summited bids will be evaluated based on the following issues.

 Compliance with the contractual terms and conditions.
 Correction of bid prices.
 Detailed analysis
Once the evaluation has been completed based on the above criteria‟s, the least bidder
will be selected and the contract will be awarded to the successful contractor. The
following formal steps will be followed after the contract is awarded.
 Write the letter of acceptance
 Write the letter to proceed with the works
 Performance bond is needed as per guarantee (10% from the total price)
There are different methods & types of construction contracts. The owner generally
makes the selection. The type selected depends on the kind of work being performed
and the conditions under which it is being performed.

1.2.4 Construction stage

Here is where the actual execution of works takes place as per schedule. First the pre
mobilization stage will be conducted which includes preparing the materials,

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 4

equipment‟s, man powers etc. then the post mobilization period will be conducted i.e.
starting the construction. The site will be controlled and the Monthly and Quarterly
Progress Evaluation Meetings will be conducted between the participants.

1.2.5 Completion and handover stage

In this stage First Commissioning will be conducted. It is a process whereb y the
contractor makes sure that all installed mechanical or electrical parts are operational.
During commissioning, therefore all such parts are run in the presence of the client or
his representative as per the conditions agreed. Acceptance/handover has the following
stages:

A, Provisional acceptance
In this acceptance, the client accepts the completed works on provisional basis for a
period one year. During this period all payments except the retention money are paid.
The other option is to release the retention money and require for a bank or insurance
security.

B, Final acceptance
At this stage the owner completely accepts the works executed and the retention
money is released to the contractor. But if the client found out some construction
default during this period, he can oblige the contractor to work out that default or the
client himself worked it out from the retention money. The contractor is assumed to
have completed his contractual obligation from this time on.

1.3 INTRODUCTION TO PROCUREMENT

Procurement is the purchasing, hiring or obtaining by any other contractual means of
goods, works and services. It is also a process used to select the lowest competitive and
qualified bidder for acquiring service, works or goods from potential competitors based on
reasonable relevant criteria. Finally, it covers all activities that involve buying, contacting,
purchasing, sourcing or tendering.

Construction Industry involves procurement and contract management systems in

order to ensure fair competition and distributions of obligations and rights among
stakeholders. Competition helps:
• The Project Owners‟ to acquire the five rights (Counterpart, Cost, Time,
Quality and Quantity).
• The Project Financiers‟ and Regulators‟ to value market principles and
Effective utilization of finance such that lowest qualified bids take the project,
• The Project Providers‟ to get impartial and neutral Opportunity for business.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 5

 Procurement is a process used to select the lowest competitive and qualified bidder
for procuring services or works or goods from potential competitors based on
reasonable relevant criteria. It can also be expressed as a method used to employ or buy
services or works or goods for the value (in the form of money) which includes
reasonable profit. Essentially, a bid or te0nder is a binding offer or proposal to furnish
certain specified promises for the amount stated in the tender.

Physical infrastructures are cost extensive and appropriate savings obtained through
competition are the main factor behind the procurement process. An effective and
efficient procurement method ensures the following rights called the "Five Rights".
These are The Right Quality, The Right Quantity, The Right Cost / Price /, The Right
Counterpart and The Right Time.

The Right Quality: It is indeed wasteful and not necessary to spend time, money and all
the efforts for procuring unqualified services or goods or works. Therefore, it is essential
to ensure whether such procurements are of the right quality. Right Quality is always
based on two major factors. These are the technical expectation and the economic
consideration, i.e.; Price & Availability.

While the technical quality can be insured by the provisions of specifications and
checking their conformance reliability of the intended job; the economic consideration
can be taken into account by the competition initiated using procurement processes.
This implies that a tender document should, as much as possible, clearly specify the
quality requirements and allow participation of qualified and experienced firms for
tendering.

The Right Quantity: The quantity should be computed carefully and included in the
BOQ correctly. This is because it has an effect on the project cost and site organisation
which is the bases for offering the right price. If the quantity is found mistakenly small,
it will have consequential effects such as:
• Project Budgeting will be affected due to excess quantities
• Construction planning will be affected and cause under stocking
• Tenderers can manipulate their offer due to it
• Overzealous contract administration is caused, and
• Contractor cash flow will be affected.
On the other hand if the quantity is mistakenly more, it will cause high stocking, more
storing places and risk of spoilage; unhealthy practices due to over budget provisions;
and manipulation in tendering. Therefore, provisions of the right quantity resolve the

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 6

 occurrences of the above stated effects. Two major factors that can play important
role in providing the right quality are Take-off-Sheet Measurements and Resources
Allocations.

The Right Cost / Price /: In strict terms the right cost usually relates itself very much to
the quality expected to accomplish the task. It is clear to say that it is difficult to get the
right cost, however to approach it, is a possibility. That is one of the causes for
procurement to be processed. Tendering together with negotiation and market
intelligence techniques is the only way that ensures the right cost and accomplishing the
task successfully. Competition is the bases for determining the Right Cost or Price.

The Right Counter Parts: This is to guarantee that the parties agreeing to accomplish
the task shall be fit to the job. That is, the Project Owner should know what his needs
are as accurately as possible, be competent to act as an Employer and should possess
the finance. The Consultant shall exercise reasonable skill, care and diligence in the
performance of his obligations. If authorized to certify, decide or exercise discretion,
the Engineer do so fairly between the client and the third party not as an arbitrator
but as an independent professional acts by his skill and judgment. The contractor shall
be able to execute and maintain the task successfully with due care, diligence and
provide all labors including supervision thereof, materials, equipment, etc. Therefore,
with the help of tendering, it is possible to select the right counterparts.

The Right Time: The right time for the provision of resources and accomplishment
of obligations of each party shall be set and agreed. This usually relieves the extra cost
incurred on the parties which will make them to suffer. Besides if the project is not
completed at the right time, its effects are devastating. To insure prevention of such
happenings scheduling with regard to right timing is essential.

1.3.1 TYPES OF PROCUREMENTS

Procurement types can be classified based on the things to be procured and the way
how they are procured. The Things to be procured are: Goods Vs Services Vs Works
There is six bases for classifying procurement methods. These are:

Things Bidders Geographic Procurement Procuremen

‟ al t
Bases Procured Coverag Awareness
e Coverag Steps
e

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 7

 Types Goods Competitive Internation General Single Two
Service al Regional PN Staged Pre
s Negotiated National Specific –
Works Local PN Qualificatio
n Post –
Qualificatio
n

Based on things to be procured, procurement types can be classified into three

major categories; namely, Procurement of Goods, Services and Works. Depending
on the delivery system chosen during the contract planning phase, mixed types of
procurement types can be adopted.

Procurement of Goods: Physical resources used as components for undertaking

consultancy services and/or construction works such as Materials and Equipment‟s are
made available using Procurement of Goods. Raw materials, products, components,
etc… are examples for the procurements of goods.

Procurement of Services: In the construction Industry procurement of services are

often termed as consultancy services a n d n o n - c o n s u l t a n c y s e r v i c e
procurements. c o n s u l t a n c y s e r v i c e p r o c u r e m e n t includes services like pre-
feasibility and feasibility studies, design and contract administration of projects,
Construction management consultancy services, research or study based consultancy
services, etc. non consultancy service procurement includes, Services that are not
related to professional skills like Transportation, Insurance, Repair work, Printing
and duplicating books etc…

Procurement of Works: In the Construction Industry procurement of works mean the

procurement of contractors to carry out the actual physical infrastructures. Building,
Transport, Water projects and related Infrastructures which normally require
construction at a specified site over a period of time.

1.4 Procurement and Contract Management

Procurement and Contract Management involves three major processes: Contract
Planning, Procurement Management and Contract Management.

1.4.1 Contract planning

Construction projects are components of a certain business or development demands.
That is, they are formulated if and only if such businesses or development

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 8

demands acknowledge their contribution and it is a must to involve them. This
requirement is dealt during the basic / strategic planning phase of the overall business.
This phase often pass through the identification, feasibility and financing stages of
Programs or Projects. Contract is a customary tool used to implement formulated
programs or projects. As a result, contract planning becomes part of this basic /
strategic phase.

Contract planning includes decisions on proposed Delivery Systems, Procurement

Methods and Contract Types to be followed and used together with its provisions for
alterations. This is because such decisions are related to regulatory requirements such
as:
 Ethical (neutrality, formality and
impartiality.
 Economical (proof of competition,
least qualified and evaluated bidder.
 Accountable (obligations and rights)
 HSE (Health, Safety and
Environment); and
 Transparent (accessibility and notice
of advertisement
Procurement and Contract Management processes shall be based upon the
approved contract planning provisions; that is, the contract delivery system, the
procurement method and contract types decided upon. The approved contract
provisions can only be changed following the change process stated in the contract
planning document and if and only if:
 The Environment and Context considered are not correctly
analyzed
 Their application can affect the objective of the project
 Procurement management process justifies change of the
Contract Types

Once the validity of the contract provisions are checked once again and taken for
granted or other provisions are devised; Procurement Management followed by
Contract Management can be initiated, planned, implemented, monitored and closed.

1.4.2 Procurement management

Procurement Management is a process of selecting individuals or organizations to
carry out the intended services and / or works. Procurement Management is carried
out based on the provisions made during the contract planning phase of the

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 9

Procurement and Contract Process. It involves the preparation of procurement
documents, their invitation and submission of tender proposals, and Opening and
Evaluation of tenders. On the bases of results from tender evaluations, the procurement
team will recommend the lowest responsive bidder for Contract Management Phase.

1.4.3 Contract management

Contract Management is a process of reaching contractual agreement for
implementation, its administration and finally concluding the contract. Similar to the
procurement management process, it shall be based on the provisions decided during
the contract planning phase. It involves negotiation based on tender evaluation
recommendations and signing of contractual agreement followed by its
administration for contractual implementation, progress tracking, and changes,
claim and disputes administrations.

The following issues are necessary for a successful Contract

Management phase:
• knowing and ensuring the implementation of contract related National
and International laws, rules and regulations,
• adherence to the provisions made during the contract planning phase
including their change processes, that is; with respect to delivery
Systems, Procurement Methods and Contract Types,
• Identifying, recognizing and involving all potential or key stakeholders
to form a contract team,
• Understanding, mapping and monitoring all contract
conditions agreed upon, and
• Ability to administer changes,
claims and disputes.

1.5 Procurement and Contract Delivery Methods

It is a process by which a "construction manager" is added to the construction team to
oversee some or the entire project. The most practiced delivery system in construction
industry of Ethiopia is design bid build (DBB). However developments in the industry
brought sophistications in the design development and construction methods. These leads
to a better delivery system to handle construction projects in better way and handover to
the client without affecting cost, time, quality of projects. Hence construction
management delivery system is becoming the more advantageous for the construction
industry of Ethiopia.

Construction management is one of the six major categories of project delivery systems
in common use for building construction projects, the other being

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 10

 force account
 the traditional design-bid-build system
 The design-build system.
 finance/ Build Operate systems(BOT)
 Alliances and Outsourcing

The relationships, roles, and responsibilities of the parties involved vary considerably
under different project delivery systems. Consequently, selection of the project delivery
system is one of the most important decisions affecting the success of a project. It is a
decision that needs to be made very early in the process. Each of the major project
delivery systems has its advantages and disadvantages in different circumstances and
may be more or less suitable for a particular project.

In this paper it is tried to address the Construction Management Delivry system as

opposed to other delivery system.

1. Force account;

When the Project Owners engage themselves to undertake the project, it is called a force
account delivery system. Often such a system is promoted if the Project Owners
believe that there is a comparative advantage in Cost, Time and Quality issues. Besides,
when there is a lack of capacity from the private sector to undertake very large and
technologically new projects, public companies do undertake such projects using Force
account delivery systems.

These days this type of delivery system is often used when projects are small and places
are remote such that reaching them is difficult and in general they are not attractive
enough to call the attention of Bidders. Besides when projects are spatially scattered and
maintenance are to be done for schools, colleges, health centers etc., such cases can be
applied.

2. Design-Bid-Build (DBB)
The design-bid-build project delivery system is the traditional method that has been used
for many years in both public and private construction projects. It is the project delivery
system that is most widely used today and which is still required by some states. The
design-bid-build process is a well-understood delivery system in which risk is minimized
through the owner's firm control of both the design and construction phases. The design-
bid-build process offers checks and balances between the constructions participants.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 11

Under the design-bid-build project delivery system, the owner contracts separately for the
design and construction of the project. The owner contracts directly with a design
professional for the preparation of plans and specifications and assistance in the bidding
stage. The design professional may also provide oversight of the project during the
construction phase. The owner enters a separate contract with the general contractor for
the construction of the project. Under the design-bid-build project delivery system, the
owner retains responsibility for overall project management. All contracts are executed
directly with the owner. The design of the project is complete before the contractor is
selected and the contractor is generally selected through a competitive bid process with
the assistance of the design professionals.

Some of the advantages of the design-bid-build process are that it provides checks and
balances between the design and construction phase of the project, it is widely used and
familiar to construction participants, and it is perceived to be a fair process in which the
lowest most responsible contractor is selected for the construction of the project.
Additionally, the owner is able to provide significant input into the process during the
design phase. When a competent contractor commits to a lump sum price, the owner can
normally rely upon the accuracy of the price and the owner is able to compare bids to
obtain the best price for construction.

Some of the disadvantages of the design-bid-build process are that it is a lengthy process,
it places the owner in the middle of disputes between the contractor and design
professionals, the cost of construction is unknown until bids are finalized, and it
intensifies the potential for change orders. The process requires a significant economic
commitment by the owner at the front end of the project by requiring the owner to
complete the design before bidding the construction of the project. Because the plans and
specifications are completed prior to bidding the construction phase, there is a potential
that bids for construction may exceed the owner's budget and hence require the owner to
either redesign or abandon the project. Some of the disadvantages of DBB for which CM
delivery systems are preferred include:
 Innovation not optimized
 usually cost overruns
 disputes between parties
 client retains most risks
 usually low bid –incentive for change orders
 owner responsible for errors & omissions
 linear process

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 12

3. Design-Build (DB)
The design-build project delivery system is a system whereby the owner enters into a
contract with a single entity that will assume the obligation of furnishing design,
supervision and construction services during the project. The design-build project
delivery system is an attractive alternative to the design-bid-build system because it
provides a single point of responsibility for design and construction. It has the advantage
of taking the owner out of the middle of disputes between the contractor and design
professionals.

It has the disadvantage, however, of eliminating the checks and balances that occur when
the design and construction phase are contracted separately. The owner also loses a good
bit of the control that it has on the project under the design-bid-build process and also
loses the direct advisory relationship with the architect that it has in the design-bid-build
process.

Some of the disadvantages of DB for which CM delivery systems are preferred include:
 most risks transferred to the design-builder
 design reflects contractor strengths & ability
 more rewards/profit for contractors
 usually guaranteed maximum price (GMP) with out cost control
 limiting competition
 high tendering costs
 new method & unfamiliar with process
 client needs to make quicker decisions
 clients bringing design requirements > 30% (reduces the innovation)

4. Finance / Build Operate Transfer (BOT)

Build - Operate - Transfer is a form of procurement and contract delivery system that
promotes Public Private Partnership in which a private company is contracted to finance,
design, construct, and operate for a certain period (usually 10 years) and transfer.

BOT contractors look to project financiers for the realization of projects through equity
contributions or credits. Such provisions are different from budgeted finances such that
they involve no or limited re – course which means the project owner is not responsible
for any liability other than force majeure and agreed upon claim adjustments. This
obliges that projects should first be viable for revenue generation in order to payback its
depts.

Some of the advantages of BOT include the following:

 Complete projects that could not normally be accomplished with internal funding

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 13

  integrates the process of design, construction, and maintenance
 maintenance & any operations aspects can be considered during design
 projects completed faster
 better life cycle costs
 better net present value (NPV)
 similar benefits earlier mentioned in D-B
 private financing with no revenue risk
 usually for ring roads
 includes the operations aspects
 ownership is transferred

It is also important to know some of the disadvantages that limits its application include:
 costs more in the long run
 longer tendering process
 costly tendering
 similar disadvantages as earlier mentioned in D-B
 difficulty with long-term relationships
 future political changes may not accept/agree with prior agreements/commitments
 difficulty with long-term relationships
 future political changes may not accept/agree with prior agreements/commitments

1.6 PROCUREMENT MANAGEMENT

The procurement management starts from the beginning of the project and it includes the
following phases.

1.6.1 procurement preparation phase

First the procurement team will be established. In this team a minimum of five members
shall be established. Necessary experts shall be included then the tender documents will
be prepared. Tender documents are prepared to
 Instruct bidders on the procedures for the preparation and submission of
bids.
 Inform prospective bidders about the nature of things to be procured
 Inform bidders about the criteria for the evaluation and selection of a
successful bidder.
 Lay down the contract conditions, delivery system, procurement methods
and contract types of the project.

Tender documents includes

 Form of invitation to tender or request for proposals.
 Instruction to tenderers

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 14

  Pre-qualification documents if necessary.
 Form of tender
 Forms of contract agreement
 General and particular condition of contract.
 Bill of quantities and drawings
 Technical specification and method of measurement
 Other forms formats and schedules.

1.6.2 Tendering phase

This phase includes
A, Invitation
 The owner and his works.
 Eligibility requirements.
 Place to get further information.
 Where to purchase and submit documents.
 How long the tender will be floated.
 How the tender offer should be packed.
 When and where submission and opening of tender will take place.

B, Clarification
This phase can either be requested by interested bidder or carried out using a pre tender
clarification meeting. Issues clarified will be sent to all bidders participating for the
intended services or works. The bidders shall submit their offer on or before the
submission date and time including the issues clarified. Late bidders are automatically
rejected.

C, Tender opening
In this phase, Bids shall be opened in public at a date and time mentioned in the invitation
to bidders. In Ethiopia when the tender is opened two representatives should be there.
 The project owner, consultant (if available)
 Contractors who wish to attend by themselves or by their representatives
shall attend during the tender opening ceremony
The following procedures will be carried out during the tender opening
 Tender attend members shall take their place and be registered.
 Tender box opened and check for faulty things
 Check the tender is the right one
 Bids will be opened one after the other
 All necessary data which is useful such as project name, name of bidder, bid bond
amount.... will be read loudly for the tender attend members.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 15

  Bidder‟s representative should sign a register to attest their presence during
opening.
 Tender committee members shall sign on the tender.

D, Tender evaluation phase

The evaluation phase means that to determine the winner based on
 Technical qualification
 Completion time
 Commercial terms to the offer.
In some cases, least bidder may not necessarily be the winner because the qualification is
not only based on the cost. Based on the above three criteria's the following evaluations
has been taken place.
 Preliminary evaluation.
 Detailed Evaluation.
 Award of Contract
 Signing of Contracts
 Preliminary evaluations; the committee will examine the quotations to
determine whether the quotations are complete. the considerations in this
requirements are Valid and up to date trade and professional license, Valid and
up-to-date membership to financier organizations, Valid provisions of bid security
or bond, Completeness and submittals of all required documents, Turnover
requirements fulfill, Appropriate invitation packaging and submission
requirements
 Detail evaluations; Includes technical, commercial and commercial qualification
requirements. Critical evaluation of technical and financial offers will be carried
out. Finally the financial offer will be updated using absolute results from
commercial comparisons.
 Award of contract; When the Engineer has completed the evaluation of tenders,
he will make a recommendation to the Employer on the award of the Contract. If
the Employer agrees, a Letter of Acceptance to the successful bidder will be given
from the employer.
 Sign of contract; after the letter has been written, then the contract will be signed
between the contractor and owner.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 16

 CHAPETR TWO
CONSTRUCTION CONTRACT
2.1 Principles of Contract Law
Contract is a written agreement between or among two or more parties whereby each
party promises to do or not to do something and agrees to terms (conditions and
Warranties) set out in the contract. Conditions of Contract are terms in which parties in
the contract are governed / administered with. That is, it is an administrative law which is
the legally binding part of the contract. These promises and terms shall be enforceable by
law and incorporates the rights, obligations and Remedial rights of each contracting
parties.

According to the Civil Code of Ethiopia, Art.1675: A contract is an agreement

whereby two or more persons as between themselves create, vary or extinguish
obligations of a proprietary nature. In other words, a Contract is an Agreement between
two or more parties to do or not to do something for a certain consideration that fulfill the
following seven requirements:
 Parties are capable of contracting: Lawful and Capable
 Consent of contracting parties is necessary: Intent
 Object of the contract is sufficiently defined, possible and lawful: Legal and
Distinct
 Use of Contract form prescribed by law, if any: Standard
 Payment for the Promise: Consideration
 Constitute two parts: Offer and Acceptance
 Parties enter into Agreement: Agreement

Lawful and Capable is to mean they are legally allowed to enter into contract and
provides statements of facts (statement of opinion + Knowledge) for their ability
to perform their obligations. Misrepresentations of facts both from Fraudulent or
Innocence actions are liable for damages and / or rescission. Intent is willingness or
consent by the contracting parties to create a legal contract. Legal and distinct is a
description of both the promises and considerations (including rights and obligations)
clearly and distinctly stated and they should be practicable and legally binding. Standards
can be conditions, forms, formats, schedules, instructions, etc which are created for use as
part of contracts. Consideration can simply be interpreted as „price for the promise‟
which involves a benefit accrued from the offeree in exchange for the promise the offeror
is bound by the contract. An Offer is an indication that one party is willing to be bound
by specific terms set out in the contract.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 17

2.2 Types of Construction Contract
There are different types of contracts classified based on. Nature and Complexity of
Works ,Size and Duration of Contract, Previous Experiences of Employer, Standard
Documents of Funding Agency, Degree of Definition/risk/Uncertainty, Status of Design ,
Technical/Supervisory Resources of Employer, Budgetary/Financing/Borrowing
Constraints

A. Lump Sum Contract

In this type of contract, the contractor offers to do the whole work as shown in drawings
and described by specifications, for a total stipulated sum of money. Lump sum contract
are typically used for buildings. The qualities of the materials required can be calculated
with sufficient accuracy during the bidding process to allow contractors to submit a
single lump sum price for the work.

There are no individual rate quoted, thus it becomes difficult to make adjustments in the
contract value of any changes are to be made in the work later on. A lump sum contract
is more suitable for works for which contractors have prior construction
experience. The experience enables the contractors to submit a more realistic bid. This
type of contract is not suitable for difficult foundations, excavations of uncertain charter,
and projects susceptible to unpredictable hazard and variations.

B. Unit Price or Bill of Quantity

Also called a schedule contract, in this contractor undertakes the execution of work on an
item rate basis. The amount to be received by the contactor depends upon the quantities
of various items of work actually executed. The payment to the contractor is made on the
basis of detailed measurements of different items of work actually done by him. Unit-
price contracts are used for work where it is not possible to calculate the exact quantity of
materials that will be required. Unit-price contracts are commonly used for
heavy/highway work.

C. Lump sum and scheduled contract

This is similar to the lump sum contract but schedule of rates is also included in
the contract agreement. In this type of contact, the contractor offers to do a particular
work at a fixed sum within a specified time as per plans and detailed specifications. The
schedule of rates for various items is provided which regulates the extra amount to be
paid or deduced for any additions or deletions made during the progress of work.
Measurements of different items of original work are not required but extra items are
required to be measured for payment. The original work shall however be checked and
compared with the drawings and specifications. This type of contract is more suitable for

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 18

construction works for which contractors have prior work experience and can
consequently estimate the project cost more realistically.

The designer may calculate that 1,000 m3 of earth needs to be moved, but the owner and
contractors know that after the work has been completed, the contractor may not move
exactly 1,000 m3. The exact quantity will usually vary. Contractors submit a price for
each item on a unit-price contract. Unit prices are multiplied by the engineer‟s estimated
quantities and totaled. The low bidder is the bidder with the low total of the all items.
Items whose actual quantity varies from the estimated quantity by more than 15 or 20%,
either above or below the estimated quantity, are sometimes subject to renegotiation of
the unit price.

The unit price contracts are usually presented in the Bill of Quantity. A Bill of Quantity
(BOQ) shows the items present for the construction work with the associated
specification and the estimated quantity with the Unit price for each of the items. The
item rate contract is most commonly used for all type of engineering works financed by
public or government bodies. This type of contract is suitable for works which can be
divided into various items and quantities, under each item, can be estimated with
accuracy

D. Cost plus
Cost plus (cost reimbursable) contracts are used in situations that make it difficult or
impossible for either the owner or the contractor to predict their costs during the
negotiation, bid, and award process. Factors that may make the calculation of costs
impossible include unpredictable and extreme weather conditions such as would be
encountered in the Antarctic, known transportation requirements to remote locations,
combat or war, or contracts where the amount of effort that will be required depends on
another contractor‟s work.

Cost plus contracts take many forms, the most common being cost plus fixed fee and cost
plus a percentage. Most owners prefer cost plus fixed fee because then the amount of
profit the contractor will earn cannot increase, thereby removing any incentive for the
contractor to be anything less than thrifty, or to produce poor-quality work. Cost plus
percent contracts may be fair in situations that are very difficult, or when the time to
complete the work is not known with any certainty, but some incentives to maintain
productivity are needed.

D.1. Cost plus Fixed Fee Contact

Cost plus fixed fee contract is desirable when the scope and nature of the work can at
least be broadly defined. The amount of fee is determined as a lump sum from a

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 19

consideration of the scope of work, its approximate cost, nature of work, estimated
time of construction, manpower and equipment requirements etc.

In order to negotiate such a type of contract, it is essential that the scope and some
general details of the work are defined. The contractor in this type of contract is selected
on the basis of merit rather than the fee alone. In case of cost plus percentage contract,
the contractor has a tendency to increase his profit by increasing the cost of work. But
this drawback is overcome in cost plus fixed fee contract because here the contractor‟s
fee is fixed and does not fluctuate with actual cost of work. Once this fee is fixed, the
contractor cannot increase the cost of work.

D.2. Cost plus Percentage of Cost Contract

In this type of contract, instead of awarding the work on lump sum or item rate basis, it
given on certain percentage over the actual cost construction. The actual cost
construction is reported by the contractor and is paid to him by the owner together with a
certain percentage as agreed earlier. The contractor agrees to do the work in
accordance with the drawings, specifications and other conditions of contract. In this
type of materials and labor are arranged between the client and the contractor. The
tendency of the contractor to increase the cost of work to earn more profit by way of
percentage of enhanced actual cost is the major demerit of this contract type.

2.3 Contract documents

Contract documents are the basis on which a construction contract is carried out. The
documents should explain in detail of all the requirements of the project in a clear and
unambiguous way. The documents also identify all the rights and responsibilities of the
main actors of contract. (Employer, Contractor and Engineer).

Contract documents contain the following which are mutually explanatory.

In case there is a conflict between documents the order of precedence of the documents
may be set i.e conflicting matters should be resolved in favor of the documents having the
higher priority.
a) Form of agreement
b) Letter of acceptance
c) Form Tender (bid)and its appendix
d) Conditions of contract
e) Specification
f) Drawings
g) Bill of quantities
h) form of Guarantees (bond)

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 20

 i) others (method statement, contractor's tender correspondences in which the
parties have negotiated the agreement etc.)

a. Form of agreement
The form of agreement is specially prepared form which contains a legal
undertaking between the employer and contractor. i.e the contractor promises
to construct the works in accordance with the contract documents and the
employer covenants to pay the contractor at the time and in the manner
stipulated by the contract agreement.

b. Letter of acceptance
This is a confirmation of the acceptance by the employer of the contractor's
offer. The letter of acceptance contains:

 Acceptance of Contract price as corrected or modified in accordance

with the Instructions to Bidders.
 Instruction to proceed with the execution of the works in accordance
with the contract document.

c. Form of tender (bid) and its appendix

The Form of tender is the contractor's (tenderer's) written offer to carry the
works in accordance with the contract document. It is a promise by the
tenderer that he will carry the works with a specified tender sum and
complying fully with the requirement of the contract document.
The Appendix to tender mainly defines the following items:
i) Amount of performance bond which is normally 10% of the tender
sum
ii) Minimum Amount of insurance
iii) Time for issuing notice to commence
iv) Time for completion
v) Amount of liquidated damage
vi) Limit of liquidated damage
vii) Period of maintenance (defects liability period) normally 12 months
viii) Percentage for adjustment of provisional sum
ix) Percentage of the value of goods and materials to be included in
payment certificates usually 70 – 80%
x) Percentage of retention
xi) Limit of retention
xii) Minimum amount of interim certificates usually one half of the
engineer's estimated average monthly value.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 21

 xiii) Rate of interest upon unpaid sums

d. Conditions of contract
General Conditions (standard conditions)
Construction contracts include a set of conditions which lay down procedures
of general applications. They define the terms of the contract, the rights and
responsibilities of the parties to the contract (employer and contractor) and
responsibilities and powers of the Engineer.

The standard contracts in use in Ethiopia are mostly FIDIC (for International
contracts ), "Standard Conditions of Contract for Construction of Civil Works
Project", of Ministry of Works and Urban Development (MOWUD,1994),
and National Competitive Bidding by the Ethiopian Roads Authority.
Some of the advantages of standard documents are:
 The parties will be familiar with their terms as result of common
(frequent) usage.
 Avoids drafting contract for each project.
 Time for the preparation of contract conditions is saved.
Standard condition of contract deal mostly with:
a. General obligations of the parties
b. Workmanship and materials (provision for quality and inspection)
c. Commencement, time delays and extension of time
d. Completion and maintenance
e. Variations
f. Contractor's equipment & material
g. Measurement & payment
h. Subcontracts
i. Procedure of claims
j. Notices
k. Settlement of Disputes
l. Tax matters
m. Price fluctuation

Particular conditions of contract

The General conditions (standard conditions) are usually prepared to set
out procedures of General application which can be used for different
type‟s projects without any modifications. Additional conditions are
required to adapt the standard conditions to the particular project. These
conditions are called "special conditions" or "conditions of particular
application". Incase any conflict between the special condition of contract

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 22

 and the standard conditions of the contract arise the special conditions
shall prevail.

e. Specifications
Specification document describes the works in technical details. It defines the
quality of material and workmanship required and any special responsibilities
of the contractor which are not covered by the conditions of contract.
There are two parts in the Technical Specification
 General information and general duties and obligations of the
contractor not covered by the conditions of contract
 Description of materials and workmanship
Technical specification can be prepared by one of the following methods:
- Make reference to existing standards specifications
- Prepare detailed specification
- Describe performance required and giving freedom to the contractor for
the details.

f. Drawing
Drawing have many functions (John murduch et al) 2000.
- They form a model of the designer's idea and help to articulate and predict
problems with fabrication and with appearances
- drawings are the vehicle, by which designers intentions are conveyed to
the contractor.
- Drawings form a record of what has been done i.e as built drawings.

Notes on drawing may contain items which may conflict with the provisions
else where in the bill of quantities or in the specification. Another problem
which may arise in a large complex projects (eg. buildings) are the
coordination between the different disciplines of the design. In this case if
drawings are not well coordinated it may give rise to construction claims.

g. Bill of quantities
Bill of quantities is list of items defining briefly the works to be done and
quantities of the work.
The bill of quantities consists of the following:
a) preamble to the bill of quantities
b) day work schedule, if required
c) work items
d) grand summary
Bill of quantities are used

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 23

  during tendering contractors will have common basis for their pricing
 assessment of interim payment certificates
 standardization of the description of the works
The applicable rules are set out in a standard method of measurement.

2.4 Contract Management

It is the management of contracts within a project.
Contract management includes
• Negotiating the terms and conditions in contracts
• (tender preparation / tendering / contracting)
• Ensuring compliance with the terms and conditions (controlling)
• Documenting and agreeing any changes that may arise during its
implementation or execution (Change order Management)

2.4.1CONTRACT ADMINISTRATION AND CLOSING

It is identifying contractual responsibilities to stake holders. When the administration of

the contract has been conducted, terms of contract documents will be reviewed,
monitoring activities will be extracted, monitoring responsibility summary sheets will be
Prepared, the construction components of the project will be Determined and understood,
the contract drawings and technical specifications will be Reviewed, the construction
methods and sequences will be extracted, construction methods and over all sequence
sheets will be Prepared, summited schedules and break downs for operations will be
Reviewed. Record monitor and evaluate progress of mobilizations, works and
completions, Report project status daily/ periodically, Qualify quality of materials
samples, workmanships, Measure works, record site potentials and certify payments and
completions.

2.4.2Claims and Dispute Management

Dispute is the difference in a line of thought. Claim is mostly concerned with
entitlements and liabilities arising under a legally valid contract.
The main causes of claims are
 Extra work/variations
 Design change
 Differing soil/site conditions
 Untimely payment
 Limited access to the site
 Defects in plans & specifications
 Failure to approve drawings
 Changes in cost

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 24

  A construction claim is a demand for
 Payment of additional compensation
 Adjustment of the parties‟ respective contractual obligation.
 Extension of time
 Compensating delay damages
 Any other change with regard to the contractual conditions.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 25

 CHAPTER THREE
SPECIFICATIONS
3.1 Introduction

Specification is defined as the designation or statement by which written instructions are

given distinguishing and/or limiting and describing the particular trade of work to be
executed. In short specification is a statement of particular instructions of how to execute
some task. Specification is one of the contract documents.
Specifications are written based on the prepared design, drawings, general and scientific
trends of workmanship, quality expected, equipment involved and materials to be used
for the particular trade of work. The specifications should clearly specify: -
 Design and drawing
 Labor employment
 Materials to be used
 Construction method
 Equipments used
Specifications should be clear, concise, and brief descriptions of what is required to
execute the proposed trade of work. The information that is needed for building
construction is usually conveyed by two basic communication lines. They are: -
 The drawings (pictorial)
 The specifications (written)
In so doing the methods of communication should compliment each other and neither
should overlap or duplicate the other. Specifications are devices for organizing the
information depicted on the drawings and they are written descriptions of the legal and
technical requirements forming the contract documents. Their difference is that the
drawings should generally show the following:
1. Dimensions, extents, size, shape, and location of component parts
2. Location of materials, machineries, and fixtures
3. Interaction of furniture, equipments and space
4. Schedules of finishes, windows and doors
Specifications generally describe the following: -
1. Type and quality of materials, equipments, labor or workmanship
2. Methods of fabrication, installation and erection
3. Standards, codes and tests
4. Allowance, submittals and substitutions
5. Cost included, insurance and bonds
6. Project records and site facilities.
3.2 Purposes of specifications
1. Guide the bidder at the time of tendering to arrive at a reasonable cost for the work
2. Provide guidance for execution and supervision of works.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 26

3. Guide the contractor for the purchase of materials
4. Serve as a part of contract document to limit and describe the rights and obligations
of each contracting parties.
5. Guide the bidder to identify his capacity to execute the work.
6. Serve as fabrication and installation guide for temporary and permanent works.
7. Guide the contractor for the purchase and/or hiring of equipments.
8. Serve for the owner to know what he/she is entitled to receive
9. Serve for the manufacturers of construction materials, equipments, tools etc to grade,
classify, and improve qualities of their produces.
10. Indirectly, the specifications are very much related to the legal considerations,
insurance considerations, bidding requirements, alternates and options, rights,
obligations and remedial measures for the contracting parties.
11. In the events of conflicts between specification and drawings, the specification
governs.
3.3 Types of Specifications
In general, specifications can be broadly classified into four categories as follows
1. Manufacturer’s specification: Manufacturers prepare specification of their
product for the guidance of their users, which may include property description
and installation guide lines.
2. Guide Specification : Specifications prepared by an individual or group of
individuals based on manufacturer‟s specifications, established trends of
workmanship, service and laboratory tests and research findings to be used as
guide lines for preparation of contract specifications.
3. Standard Specification: Specifications which are intended to be used as a
reference standard in the construction of a project. The guide specification which
has been standardized by a recognized authority is considered as standard
specification.
4. Contract (Project) Specification: the specification prepared for a particular
project to accompany the drawings and other contract documents.
The specifications described above can be prepared following the format which has
general and specific parts (general specification and specific specification)
In the general part of the standard specifications the following items are included:-
 Administrative and Procedural Requirements
 Scope, definitions
 Reference organizations and Standards
 Project description, site facilities
 Submittals and quality assurance
 Delivery, storage and handling
 Project records
 Insurances

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 27

  Other general requirements
In the specific part of the standard specifications, detailed description of the quality of
items to be used is given. In addition to this, preparatory actions and methods of
incorporating the items into the project are indicated.
Specifications could be written in several ways, with the prime emphasis given to either
the producer company‟s brand or the performance capacity of the material and so on.
Accordingly, there are the following types of technical specifications.
1. Proprietary Specifications: This specifications call for desired materials,
producers, systems, and equipments by their trade names and model numbers. For
detailed descriptions reference should be made to manufacturer‟s specifications.
They are of two types; closed (sole) source and open or equal source.
2. Performance Specifications: specifications which define products based on
desired end results which are performance oriented; most appropriate when new
or unusual products or systems are required or when innovation is necessary.
Describing the problems or conditions under which the products or systems must
operate, and the parameters for the acceptable solutions is difficult and
challenging. Testing methods and evaluation procedures for defining the required
performances must be explicitly specified.
3. Reference Specifications: Specifications which refer to levels of quality
established by recognized testing authority or standards set by quality control
authorities. These specifications are also used in conjunction with other types of
specifications.
4. Descriptive Specifications : Specifications which describe all components of
products, their arrangements and methods of assembly, physical and chemical
properties, arrangement and relationship of parts and numerous other details. The
specifier shall take total responsibility for the function and performance of the
product.
5. Cash Allowance Specifications: Specifications meant to direct bidders to set
aside a specified amount of money to be applied to the construction work at the
direction of the specifier.
3.4 Specification writing
Basically specifications are not to be created; they are prepared based on existing
standards, codes, guidelines, and laws.
Specification writing embodies certain methods of presenting information and
instructions. When specifications are to be written, the following shall be taken into
consideration:-
a) Specification writing require
1. Visualization (having clear picture of the system)
2. Research (to know the legal impact correctly)
3. Clear thinking (understanding things directly without misleading)

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 28

 4. Organizing (organizing what we know to write the specification)
b) Specification writing require professional ability to read drawings
c) Specification writing require wide knowledge of the construction materials,
various levels of workmanship, different construction equipments and method
of construction to be employed
d) Specifications use simple and clear language such that it can readily be
understood.
e) Specifications shall be brief and short as much as possible (avoid long
sentences without punctuations)
f) Specifications shall include all items affecting the cost of the work
g) Specifications shall be fair and do not attempt to throw all risks and
responsibilities on one of the parties signing the contract, the employer or the
contractor.
h) Specifications shall avoid repetition of information shown on drawings to
avoid mistakes and duplications within the specifications and drawings
i) Specifications shall not include inapplicable text and do not specify the
impossible or anything not intended to be enforced.
What are the useful references in specification writing?
The following are useful references in Specification Writing: -
1. Codes and ordinances of governments, cities, or municipalities. For example,
EBCSs
2. Standards prepared by distinct societies and government agents. For example,
ACI standards, ASTM standards, BS, ES.
3. Standards or model specifications prepared by manufacturers, professional
societies, and government bodies.
4. Master specifications and previously written specifications.
5. Information or experience acquired by personal observation and contact with
trained or experienced people in the construction industry.
Specification language
The specification writer should present his instructions regarding the particular work
under consideration in such a manner that: -
1. The drawings are more clearly interpreted, not duplicated.
2. Rights, obligations, and remedial measures shall be designated without
ambiguity or prejudice.
3. Clearly express the extent of works under consideration; therefore, the
phraseology used in this regard shall be: -
i) Judged by its quality not its length
ii) Should be concise and short and written with commonly used words
iii) Punctuations are important but their usage shall be limited to few
iv) Capitalizing the first letters is mandatory for the following expressions: -

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 29

 a) Parties to the contract; eg Employer/Client /Contractor/ Engineer
/Architect
b) Space within the building; eg Bed Room, Toilet, Living Room
c) Contract documents; eg Bill of Quantity, Working Drawing,
Specification
v) Minimize pronouns, better to repeat nouns
vi Minimize the use of symbols
vii Do not use foot notes, do not underline within a sentence for emphasis
vi) Words shall be used as follows:-
a) shall in place of must; use “shall” for the duties of the contractor or the consultant to
represent the word “must”
b) “will” is used for the duties of the employer to represent the word “must”
c) “must” –avoid the use of the word “must” and substitute by the word shall to prevent
the inference of different degrees of obligation
d) Avoid the use of words which have indefinite meanings or limitless and ambiguous in
their meanings. For example, any, either, same, similar, etc.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 30

 CHAPTER FOUR
QUANTITY SURVEYING

4.1 Introduction

Quantity surveying is a term or process used in the construction industry to take

measurements of civil works, prepare specifications, estimate the cost of works either for
each trade of work or for the whole project.
The following tasks are covered in quantity surveying:
1. Preparation of specification
2. Taking measurements of civil works (Taking off quantities and preparing BOQ)
3. Preparation of approximate (preliminary) cost estimate at the very early stage of the
project
4. Preparation of detail cost estimate at different stages (taking as built measurements and
preparing payment certificates or approval of payment certificates prepared by taking
measurements)
5. Preparation of tender documents and examining tenders (tender – an offer in writing to
execute a contract)
6. Preparation schedule of prices to negotiate with pre-qualified bidders (labour rates,
material supply rates, equipment rental rates)
7. Determination of values of works (executed works) and preparation of payment
certificates
8. Preparation of final accounts on completion of all of the works.
9. Valuation of property

4.2 Measurement of civil works

Measurement of civil works includes the billing of each trade of work either from
drawings or the building itself for defining the extent of works under each trade. The
standard book, which is used here, is standard technical specification & method of
measurement for construction of buildings by BaCoDA, March 1991.

Specification worksheet (BOQ form)

It is the format which is used in a bill of quantity to list (include) a short description of
the specification along with its measuring unit, quantity and unit prices to determine the
total cost for each trade of item.

Project

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 31

 Item Description Unit Quantity Unit price Total
price

There are four clearly defined steps in preparation of Bill of Quantities:

1. Taking off 2. Squaring 3. Abstracting 4. Writing the final Bill

Taking off
This is the process of preparing / defining a detailed list of all labor and materials
necessary for the work and entering the items on properly dimensioned paper. The
standard form used for entering the dimensions taken or scaled from drawings to
determine the accurate quantity in each trade of work, except reinforcement steel, is
called take off sheet or dimension paper. The dimension paper used for taking off is
usually double – ruled as shown below (A4 size).

Title
1 2 3 4 1 2 3 4

page page

Column 1 is used for stating the number of times an item occurs and is called the
timising column. Column 2 is called dimension column as it is used to enter the
dimensions of the items of works.the dimensions are entered in the order indicated below.
Length
width

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 32

 height or thickness
Column 3 is called squaring column, where as column 4 is called description column.
The following tasks are part of the taking off (used to facilitate defining the quantities).
Describing the item, bracketing (relating the description to the quantity), timizing, dotting
on (adding to the timizing factor), the ampersand (ditto), waste calculations, deduction of
items, correction of dimensions (nullifying)

2. Squaring:
The dimensions entered in column2 are squared or cubed as the case may be, multiplied
by the timizing factor, and the result entered in column3. This task is called squaring. All
squared dimensions should be carefully checked by another person before abstracting,
and if correct the item should be ticked with red.

3. Abstracting:
The squared dimensions are transferred to abstract sheets and all similar dimensions are
collected in the same category to obtain the total quantity of each item.

4. Writing the Final Bill

After the abstract sheets have been completed and checked, the final bill of quantity is
written. The dimensions are copied from the abstracts, and as each item is transferred it
should be ticked by a vertical line from the abstract sheets. The description of each item
in the final BoQ should be short, precise and descriptive as per the specification.

Bending Schedule: the format used to define quantity of reinforcement bars.

Project: Bending schedule to :

Location Mark shape Diameter Length(m) No ∑ L for each diameter

Total
W/m
∑W
Basic principles in taking off

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 33

 1. Drawings shall be fully understood clearly and detailed.
2. During discrepancies in detailing, dimensioning or if missing items exist obtain
clarification from the designer.
3. The BoQ shall accurately represent the works to be executed.
4. Works, which cannot be measured accurately, shall be expressed as provisional
quantity (PQ) and will result in provisional sum (PS) and lump sum (LS)
5.Prepared in such a way that discrepancies or mistakes in taking off will not result in
excessive variation in the project cost which directly affect the budget allocation for
the project.
6. With the understanding that measurements are taken to the nearest cm.
7.Built items shall generally include all possible entrants which will make labor,
materials (including storing, loading, unloading and handling), fixing, use of plant
and equipment, wastage of materials, equipment establishing charges and profit;
otherwise it shall be stated specifically.
8. With the understanding that there is a standard paper format to carry out
measurements of civil works, namely take off sheet or dimension paper, bending
schedule and specification worksheet.
9.Prior knowledge of the regulations is necessary (For eg. roofing is measured in
horizontal projection).
10. Measurements of civil works shall be carried out in such a way that it can be
easily checked and audited.

Mensuration – the calculation of geometric quantities such as length, area, and volume,
from dimensions and angles that are already known.

Girth (perimeter) computation –linear measurement.There are various methods of taking

off quantities for computation of girth.
Centre line method –suitable only when the cross sections of all walls are symmetrical.
In this method centre line length is found and same is used for taking off quantities
(therefore only width and depth vary).
Crossing method – lengths and breadths of walls as shown in plan are taken for working
out various items and this method is useful only if the offsets of footings are symmetrical.

In- to- in and out- to-out method –some wall lengths are taken out to out and others in
to in (offsets are added to out to out lengths) and same are deducted from in -to-in
lengths; used for any type of measurement irrespective of condition of symmetry.
Exercise: - Find out quantities of earthwork, cement concrete and brick masonry in
foundation as shown in the figure by using:
a) centre line method

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 34

 b) out to out and in to in method
c) crossing method

4.3. Technical Spec. and Method of Measurements for the diff. trade of Works

A. SUBSTRUCTURE
Any structure below the ground floor slab level including the basement, retaining walls,
ground slab, grade beam, and foundation is called a substructure.
In most of the cases, substructure work can be categorized as follows
4.1 Excavation and earthworks (mandatory)
4.2 Concrete works (can be neglected sometimes)
4.3 Masonry works (mandatory)
Steel is not used in substructure unless in composite form.
4.3.1 Excavation and earthworks
What types of works are included in excavation and earthworks?
4.3.1.1 Site clearance
Carbonatious elements are not good in concrete, steel and timber works. In soils under
structures even 5% of these elements will damage the structure. Therefore, these
materials (including trees, bushes and the top 20 to 30 cm soil), termite hills, any other
obstruction, too, have to be cleared. A working space of 1m is required on each side.t is
sometimes necessary to prepare separate specification for obstructions (demolition
works) because reusable items like doors and windows are there.
4.3.1.2 Excavation (bulk excavation)
Excavation to get reduced levels of every structural element below the ground level is
called bulk excavation. They are subdivided as follows depending on the subsurface
condition.
4.3.1.2.1 Ordinary soil - with boulders and without boulders
-can easily be removed by shovel without problem.
4.3.1.2.2 Weathered rock –it can be divided easily without blasting
4.3.1.2.3 Rock- bedded rocks that cannot be dug without blasting (requires using
explosives)
 Working space for bulk excavation is 25 cm ( not used for shallow masonry)
 Depth of excavation less than 30 cm – measured per m 2 ,depth > 30 cm per m 3
4.3.1.3. Fill /embankment, measure in m3 of net volume to be filled
We need fill because the reduced level of every structural element above the structure has
to be covered.
N.B. Excavation and embankment should not be added at a time in computing their
volume, because their costs are different .The subdivision under fill are:
4.3.1.3.1 Backfill - filling of the excavated soil onto its excavated place

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 35

 - excavated material taken from below top soil
- selected excavated material (selecting coarse particles)
4.3.1.3.2. Borrow fill: - filling of soil by bringing the fill from another place when there is
shortage of fill or when better quality material is required.
The major consideration under embankment is compaction. Compaction is done usually
at 20 cm lift thickness.
4.3.1.4 Disposal - cleaning the building area including cart away.
4.3.1.5 Sundry items – application of termite proof solution, providing hard coring, dust
blinding, expansion joints, etc are itemized as sundry items; measured in m2

4.3.2 Concrete works

4.3.2.1 Concrete
Cast in situ concrete – formed on site
-Requires formwork and reinforcement
Prefabricated concrete –fabricated (manufactured) in a factory and brought to the site
- joined to make a building
- does not require formwork
- needs a special care when connecting the different elements
- fast to construct a building, though the different elements may lack homogeneity.
Pretensioned (Post tensioned) Concrete
- Bending up the concrete itself to make it ready for the downward
bending due to load. In bending due to load the beam or the slab comes to its
neutral axis.
Concrete ancillaries- windowsills, lintels, expansion joints
- permanent and temporary embedded material
- measured in ml or enumerated

Testing of concrete – destructive and non destructive tests

- Cylindrical/ cubical compressive tests to check the grade of the concrete.
- Slump test
- Structural tests (eg Non-destructive test)
- Ingredient Material test
- Constructed elements shall be evaluated for verticality and horizontality.
Accordingly, levels of floors slabs, beams, lintels, etc, intended to be horizontal
shall not slope in more than 6mm in 3mm. Errors in plumbing (vertical elements)
shall not be more than + 6mm in 3m.
Curing of concrete - concrete shall be protected from premature drying and excessively
hot temperatures and loading for at least 28 days starting from the
date of casting. The importance of this is to protect the concrete

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 36

 from shrinkage and creep. Creep is usually due to load, and it may
cause poor bond b/n reinforcement bars and the concrete.
- The concrete surface shall be kept continuously wet by application of water for at
least seven days to maintain constant temperature. But the watering of concrete
shall continue until the concrete has achieved its design strength.

Grades of Concrete
C5 - lean concrete, to protect the structural concrete from damage, which is
usually caused by dust. Thus dust blinding is required.
C15- for totally supported structural elements
C20- used for slabs; the mix proportion is 1:2:4
C25 – Commonly used grade of Concrete (1:2:3)
C30 –Used for chemical stores and nuclear plants
Cast in situ concrete shall be measured by volume except in ribbed slabs and groutings.

4.3.2.2 Formwork – measured in m2

A temporary structural element, which supports slabs, beams in casting concrete. It shall
be designed and erected to safely support, vertical and lateral loads that might be applied
until such load can be supported by the concrete structure.
Period of removal (minimum)
1. Vertical formwork to columns, walls and beams: 16 hrs
2. Soffits formwork to slab 21 day
3. props to cantilever slabs 14days
4. Soffits formwork to beams 21days
5. Props to cantilever beams 14 days

Formwork Classification
Normal finish, Fair face Finish, Patterned Finish

4.3.2.3 Reinforcement
Tests: The following tests shall be made on the reinforcement bar
- Ultimate tensile strength/ stress, yield point stress, elongation, cold bent
- The reinforcement bars are tied in 1.6 mm mild steel wire
- no concrete shall be cast until reinforcement is checked and approved by the
engineer(supervisor)
- measured in kg

4.3.3 Masonry Works

Masonry works are works that are executed by laying building material units of specified
dimension by providing a binding material such as mortar.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 37

Stone obtained from quarries shall be hard and sound, free from vents, cracks, fishers,
discoloration or other defects that will adversely affect strength or appearance.
Stone chips to be produced shall not be less than 450 mm average and 380 mm in
individual length.
Stone for various masonry works shall be selected and shaped as follows:
a. stone for facing works shall generally be selected for consistency in grain, color
and texture ,throughout the work
b. stone for below ground work shall be chiseled from natural stone
Stone wall is measured by volume, whereas stone pavement is measured by area
specifying thickness.

B. SUPERSTRUCTURE
4.3.4 Concrete works - mostly as discussed in substructure
4.3.4.1 Concrete: mixing, transporting, casting, and vibration in elevation columns,
beams, staircases, slabs, shear walls, landings. Curing of the cast concrete, strength and
workability requirements are crucial issues to be checked.
4.3.4.2 Formwork: Specify the type of material used and where to use (zigba or steel)
4.3.4.3 Reinforcement: Differentiation is made as to the diameters and where used (sub
and super structure)
Weight per unit length for Ф6 is 0.222 kg/m; for any other diameter d2, with weight per
unit length w2:
w2 = (d22/62) * 0.222
4.3.5 Masonry works
Classification of stone masonry works, measured by volume

1. Stone wall concealed from view or to be left for further finish (cheaper)
- shall be built in stone sizes of not less than 300 mm per course (one lay ) and 400
mm wide per stone
- faces of stone walls to receive further finish shall have horizontal and vertical
joints raked out to form adequate key for further finish.
2. Roughly dressed stone wall (expensive)
- shall be built in stone sizes of not less than 300 mm per course and 400 mm wide.
- The joints of the fair chiseled natural stones shall be finished slightly proud
(aesthetical) and cleaned off flush at completion
- The joints shall be raked out to a depth of 15 mm as the work proceeds and
prepared for jointing
3. Dressed stone wall facing (more expensive)
- the pattern type and size of the stone units shall be as detailed on drawings
- the joints of dressed stone wall shall be finished good and raked out to an
approximate depth of 15 mm.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 38

Hollow and solid concrete blocks, measured by area specifying the thickness
The ingredients are cement, either pumice or red ash, water and aggregates (0.1mm)
Blocks shall be manufactured from cement, aggregates, red ash, or pumice with no fine
volcanic dust.
Trial mixes shall be prepared to attain the average minimum compressive strength after
casting and curing for 28 days.
There are different classes of HCBs
Class A = 42 kg/ cm2 (for light loads)
Class B =35 kg /cm2 (for external walls)
Class C =20 kg/cm2 (for partition walls)
Class AA=70 kg/cm2 (for load bearing sub structural works)
Class A-AA= 50 kg/cm2 (for load bearing super structural works)
Class AA and A-AA shall be obtained from 0.1 aggregate not from pumice or red ash
Blocks shall be uniform in texture, size, and shape and free from any cracks and defects.
The surface of blocks shall have a good key for plaster and rendering.
The standard thicknesses of HCBs are 10cm, 15cm, and 20cm
Since there are no stones, bricks of these sizes one should know, based on the given wall
thickness whether HCB wall is used or not.

Bricks
Bricks are fire resistant, watertight and can also resist compressive action of upto 200 kPa
Bricks can be used for external, internal, retaining and load bearing walls.
Bricks shall be well made and adequately burnt, free from cracks and particles of lime.
Bricks exposed to weathering shall be selected for least in absorption, high durability,
uniform in color and texture.
The thicknesses of bricks are 25 cm (for double layer) and 12 cm (for single layer)

Adobe walls
It is a mixture of clay, water and „chid‟ with high resistance to drying shrinkage and
cracking
It shall be dried gradually; ordinary type of masonry wall, and used for very low cost
houses.
Stabilized soil block wall
It is a mixture of soil, water, and Portland cement,used for low cost houses

Building mortar (binding material)

Ingredients of mortar are:-
Cement: - usually Portland cement
Sand: - crushed or river sand with diameter less than 4.75 mm
Lime: -hydrated lime

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 39

The mix proportions are
a) Stone masonry: -1:3 mix b) Brick and block masonry: -1:4 mix
c) Compo mortar (lime): -1:2:9 mix

Construction
Any surface to receive masonry walls should be free from earth dust and wetted before
mortar is laid on the surface. Laying is possible on concrete surface or lean concrete
which is at least 50 mm thick, selected fill.
Walls separated by concrete or other material shall be built (straight) plumb and with
deviation of not more than 3mm in 3 meter.
Walls shall be constructed with no portion higher than 1000mm above the adjacent wall
at any time.
Wall below grade shall be built with cement mortar only (compo mortar decreases in
strength because of dampness)
During measurement, no deduction is made for opening up to 0.25 m2 in area

4.3.6 Roofing and wall cladding

4.3.6.1 Galvanized corrugated iron sheet (CIS)

Galvanized CIS for roof and wall cladding shall be of the required size and thickness
CIS less than G32 cannot be used for roofing and wall cladding of permanent structures
but for temporary works eg fence works, for provisional works
G26 G28 G30 G32 and G35
G26 is the thickest

4.3.6.2 Galvanized plain steel sheet (GPSS)

GPSS is used for wall cladding, ridge cup, gutter, down pipes, flashing, copping, edge
trimmers etc; shall be to the size, thickness and galvanization required; shall not be less
than G28; G24 is usually used for gutter, down pipes; Overlaps at edges shall be
minimum 15 cm

4.3.6.3 Galvanized ribbed sheets ( EGA sheets )

Usually used for factory, hall etc.
Shall comply with the requirements of the manual „KASI‟ or other standards acceptable
to the Engineer to the sizes, thickness and distance to ribs.

4.3.6.4 Aluminum corrugated sheet for roofing and cladding

The minimum thickness shall be 24 SWG (SWG = standard wire gauge)
Corrugated sheets shall have uniform corrugation parallel with the sides of the sheets.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 40

4.3.6.5 Aluminum plain sheet accessories
Used for ridge cap, gutter, down pipes, flashing, copping etc.
The same as that of 4.6.2 but aluminium made
4.3.6.6 Roof clay tiles
Tiles shall be manufactured in wet weather and prepared from clay.
Clay tiles shall show clean fracture when broken and shall not be less than 10 mm thick
Clay tiles shall be fixed to timber using roof, nails, the holes in clays shall be pierced
(using embedded in clay tiles)

Fixing accessories of roofing

Fixed to timber using chiseled or diamond edge and convex head galvanized nail drawn
from mild steel
Washers shall be diamond or flat pattern produced from rubber or bitumen coated fibre
homogenous and free from porosity (to prevent from leakage)

Hooks, bolts, nuts and screws: - Shall be fixed to steel structures; the sizes of fixing
accessories shall be as recommended by the manufacturers and match with structural
drawing.

Hangers and brackets

Used to fix gutters and down pipes; Formed from mild steel not less than 2 mm thick and
10 mm wide; Hangers and brackets shall always be primed (coated) with anti-rust paint.

Construction
Shall be given sufficient slope for drainage; Holes for bolts shall be 5 mm larger (greater)
than the diameter of bolts and the hooks and 40 mm far from the edges of the sheets
Sufficient overhang or other means shall be produced as weather protection for walls
Shall be laid with end laps not less than 15 cm and side laps not less than one and half
corrugation; Vertical cladding with end laps not less than 10 cm and side lap one
corrugation

Gutter and down pipe

Gutters shall be laid to slopes as indicated on drawings not less than 0.05 percent
Gutter and down pipes shall be overlapped min 15 cm and joints welded

Method of measurement for roofing

Roof cover, side cladding, and the like shall be measured by area (m2), flat over the
projection area without addition for slopes and laps.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 41

Ridges, flashing, down pipes etc shall be measured by length stating girth (development
length) and without addition for laps, passing angles etc.
Rain water spout shall be enumerated stating the sizes and length. The same is true for
most of prefabricated items.
The following shall be understood as included: perforating, sealing, nailing, bolting,
screwing, battens, joists, wedges, spillers, covering lists , back supports, brackets , cutting
,bracing , trimming, jointing, boring ,etc.

4.3.7 Carpentry and joinery works

Carpentry: -work on timber intended for structural purposes eg columns, beams, slab,
truss etc
Joinery: - work on timber intended for finishing purposes eg floor finishes, wall
claddings, doors and windows, ceilings etc
Carpentry
Truss, rafter, beams and columns:
Shall be made from eucalyptus, kerero, zigba, tid, or other equivalent posts
Shall be fabricated as per the detailed drawings
Posts shall be uniform in diameter and free from cracks
Posts shall be pealed off and allowed to season until the acceptable moisture content is
achieved, i.e. 20 % (seasoning = drying upto a certain moisture content)
Eucalyptus and kerero posts to be exposed to weather or buried below ground shall be
pressure impregnated
Trusses and rafter shall be tied with 6 to 8 mm diameter mild round steel

Purlins
Purlins shall be produced from eucalyptus or zigba or other equivalent posts
Purlins shall be in the sizes shown on drawings (standard dimension 5*7cm)
The splices of purlins at joints shall be minimum 60 cm
Shall be securely nailed to trusses and rafter

Joinery

I) Ceiling
Ceiling shall be built to types, size and thickness on drawings
The face of the panels to be exposed to view shall be smooth enough to receive further
finish
Soffits nailed to supporting ceiling buttons.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 42

Soffits are made of chip wood, plywood, hard board, soft board nailed to timber buttons
Minimum size of buttons is 4*5 cm and maximum spacing is 60 cm in both directions
Button shall be fixed to the truss or rafters in 4*5 cm sawn timber suspenders
The joints of ceilings to wall shall be covered with moulded corner lists not less than
50mm and joints of panels be covered with mild timber and moulded lists not less than 30
mm wide.

Suspended ceiling Soffits

Cheap wood, plywood and other ceilings suspended from supports by wire, chains and
steel profiles and materials resting on the metal profile.

Milled timber Soffits

Made of zigba or kerero
Minimum thickness is 15 mm
Minimum panel width is 60 mm
Timber boards shall be grooved and tongued
Buttons shall be 50*50 mm and c/c 50 cm spacing

II) Milled timber accessories

Fascia board shall have minimum thickness of 20 mm
Edges shall be chamfered
Milled timber cladding
Use a smooth joint that is without tongue and grove
Cladding to wall shall be to the size, shape and patterns as on the drawings.

III) Milled timber floor

Floor boards that of tongue and grooved shape
Having a thickness not less than 20 mm and minimum width of 70mm and shall be
tongued and grooved
Width of 70mm and shall be tonged and grooved
Nailed to sawn timber joists
Minimum size of joists 60x100mm c/c 50 cm
Joists shall be accurately embedded in concrete
Skirting-
machine smooth finished with minimum thickness of 20 mm and width 80mm
Edges shall be chamfered

IV) Doors windows and wall panels

Wall panels partition wall in buildings

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 43

Fully solid wall panels
Partly glazed wall panels, Fully glazed
Doorframes
Shall be notched to receive iron mongery (hinge, lock and handle)
Lists of cover joints between frame and wall shall be milled timber not less than 50 mm
wide
a) Glazed wooden doors - the side , top bottom and intermediate rails shall be
mortised and tenoned
rails shall be single width timber

b) Panel wooden doors

plywood or other panels are used in place of glazing
c) Flush wooden door
Finished thickness of flush doors not less than 40mm
Face panels on either face shall not be less than 8 mm
Cover panels if tongued, boards shall not be less than 15mm

Windows
It is the same as that of doors
Sills for windows shall be in full width timber and extending beyond the face of the wall

Wall panels
- Tongued and grooved milled timber boards not less than width of 80 mm and 15
mm thick
- If open jointed milled timber is used, width=100mm and thickness=15mm
- Block board with specified plywood exposed surface of less than 20mm thickness

V) Cupboard and counters

- Built in cupboards: - fixed cupboards on construction of the building
- Shall be constructed from milled timber and paneled boards. It has frames of
40x40 mm milled timber, fixed to wall
- The bottom part is made up of 20mm thick edge lipped block board with exposed
faces covered by plywood
- Rear, side and top part of the cupboard shall be lined with 6mm exposed face
smooth finish plywood

Drawers

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 44

 - shall be built in 20 mm thick milled timber
- bottom of drawer shall be block board not less than 6mm thick
- shall have milled timber plastic or metal guide rails to each other

Shelves
- 20 mm thick block board with upper face finished smooth and be supported on
hardwood metal or plastic support securely screwed or nailed to the cupboard
frame

Methods of measurement for carpentry and joinery

- Structural members other than truss shall be measured by length stating size (eg
columns, beams)
- Roof trusses shall be enumerated stating type and referring drawings (sometimes
measured in meter length)
- Boarding, flooring, partitions, Soffits (ceiling),curtain walls are measured by area
and shall be understood as including frames , corner lists and hard wares(hinge
,handle , lock )
- Fascia boards, eaves, skirting shall be measured by length stating girth
- Built in furniture and boards shall be enumerated stating sizes

4.3.8 STEEL STRUCTURAL WORK

Steel can resist compressive, tensile, bending and Torsional stresses
The material shall be mild steel
Profiles (shapes)
- The shape of the steel structure is determined by the Structural Engineer .The
sizes and shape shown on drawing shall be specified in description column
Steel is used for constructing:-
- Beams, columns, suspended slab, truss, rafter
- Composite structure (steel +concrete)
- Upto 15m span we can use timber trusses, but for span greater than 15m,we have
to use a steel structure

Bolts and nuts

- are used to connect (fix )structural steel with concrete or other material
- welding is usually not recommended for steel structures because it does not allow
movement
Normal type of connection between a column and truss
Function of slotting (widening ) truss connection holes is
- to correct mistakes in fixing
- for ease of access of mounting
- for expansion joint (to allow movements )

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 45

 Steel plates (steel to steel connection)
- used for splices of joints
- used for bearing plates

Fabrication
- shall follow sequences which are suitable for assembling and erection
- cutting shall be sawing, shearing (steel cutter ),copping or flame cutting
(oxyacetylene cutter)
- holes shall be drilled or punched
- holes shall not be more than 3mm larger than diameter of bolts

Assembling erection
- adequate care shall be taken to ensure that components are not bent or twisted
- bolted connection shall be drawn together
- washers shall be provided where slot holes are oversize
- anchors and embedded connection shall be set and grouted before mounting

Method of measurement
- Beams, trusses, columns and purlins, bracings, rails, etc shall be measured by
weight (Kg), identified by profiles and type of structures
- Connection plates, base plates, angle iron ties, brackets shall be measured by
weight or enumerated stating profiles and dimensions respectively
- Anchor bolts enumerated stating size and development length
4.3.9 Metal works
- Metal door window frames
- Steel profiles produced from standard grade of steel
- Black steel to be primed during fabrication and surface treated after installation
- Aluminum profiles: - wrought aluminum and alloys are used. Nuts, bolts, screws
and fasteners are coated or produced from nonoxidizing metal.

Fabrication
- Formed accurate to required profiles and sizes

Erection
- be placed accurately in position aligned, plumbed, and leveled
- they are usually door and window frames and hence no assembling of parts except
fabrication and erection

Classification
1) Casement doors and windows

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 46

 - side , bottom, and top hinged
- LTZ frame (iron made)
- SECCO profile (steel)
- RHS frames (refer KASI manual)
- SECCO profile is more expensive than LTZ (Fig)
2) Heavy duty sliding door
- Guide and roller trucks shall be in mild steel in the sizes specified
- Rollers shall be heavy duty and produced from stainless steel and be provided at
top
3) Louver window
4) Security grills
- Produced from mild steel galvanized or precoated solid plates or hollow profiles
of patterns as shown on drawings
5) Guard rails
- fastened to support securely embedded in concrete or welded
6) Wire netting and fly screen
- netted wire produced from steel
- mesh for flag screen shall not be more than 10 mm
7) Corner protection
-not less than 30 mm
- shall be securely screwed and embedded to angle of materials for protection

Method of measurement
- Doors and windows enumerated stating sizes (the glazing work shall be measured
separately)
- Curtain walls by area
- Balustrade rails, corner protection by length stating development length
- Security grills fixed to windows and doors by area
- Louvers enumerated in size stating number of blades (louver jamb sets)
The following shall be understood as included: chiseling, cutting, welding, riveting,
shaping, grinding, drilling, assembling, fixing, protective treatment , decorative paint
, frames, beads ,lining , anchors , hard wares etc(hard wares include hinge, lock,
handle
4.3.10 FINISHING WORK
1) Plastering and pointing works
The ingredients are:
- Cement (ordinary Portland cement), Lime
- Gypsum (such as plaster of Paris )
- Aggregate (fine or crushed aggregates), water
Surfaces to receive plaster, pointing or screed shall be thoroughly cleaned and wetted
The surface should be raked out to a minimum depth 10 mm to form proper key

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 47

 (If the thickness of plastering is greater than 2.5cm, it may crack)
The surface should be rubbed with cement slurry (cement +water)
Plaster
First coat: - mix proportion 1:2.5(cement: aggregate by volume)
- minimum thickness of 5 mm
- spread by trowel , stretched off level and allowed to cure for 24 hours before
applying the second coat
Second coat: - mix proportion 1:1:6 (cement: lime: aggregate by volume)
1: 4 (cement: aggregate by volume)
- max thickness of 12 mm
- dried for 21 days
Fine finish or fine coat cement plaster
- mix proportion 1:2 (cement +fine sand )
- max thickness of 3 mm
- shall be finished truly and level
We use fine sand for smooth finish as final coat
Function of first coat
- acts as a bondage between the masonry wall and the second coat
- the second coat is for minor adjustments on plumb (level ) and receiver surface
for the smooth finish (fine coat )
- function of fine finish is for aesthetical value and preparation for painting
- the fine finish coat shall be cured for seven days and allowed for 28 days before
further finish is applied
Fine coat lime plaster:
- mix proportion 1:2 (lime : fine aggregate)
- max thickness of 3 mm
- further finish up to 28 days

Fine coat gypsum plaster

- mix proportion 1:3 (gypsum :lime putty )
- max thickness of 3 mm
- cured for 28 days

Render coat
- mix proportion 1:2:5 (cement :lime : fine aggregate)
or mix proportion 1:3 (cement : fine aggregate )
- shall be manual or machine sprayed, wetted for 7 days

Float finish (Fare faced)

- Shall be applied to concrete surfaces that are to receive no plaster coat
- It is applied to only concrete surfaces not to masonry

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 48

 - A rendering coat of one cement with two fine aggregate shall be applied and
surface floated. Cement dust or cement paste shall be applied to the floated
surface
Cement pointing
- mix proportion 1:2 (cement :fine aggregate)
- can be flush or recess pointing
Flush pointing: finished level and even to the wall
Recess pointing: depth not less than 5mm
Pointed surface shall be cement dusted or cement pasted to form smooth surface and
wetted for seven days

Method of measurement
- plaster and pointing works shall be measured by area . Internal and external works
shall be measured separately
The following shall be understood as included.
- preparing background , hacking out joints , grouting , jointing , recessing etc

2) Floor and wall finish

Terrazzo tiles: -used for floor finish and skirting
- shall be precast or cast in situ elements
- shall have a minimum topping of two parts of marble or granite chipping from an
approved quality with one part cement
- the minimum grading of the chip shall be 5mm
- usually have a thickness of 2 cm
- shall be applied onto 3 cm thick cement screed bedding (specified thickness )
Precast cement tiles
- produced from crushed aggregates (0.1 mm gravel) and sand mix
- minimum thickness shall be 20mm
- shall be applied on 3 cm cement screed bedding
- cheaper than terrazzo tile
Marble tiles
- shall be in accordance with quality, color and texture as shown (specified )
- shall be straight edged and smooth surfaced
- cement mortar backing for walls and cement screed bedding for floors
- recently techniques of binding the marble with wall leaving space between them
(for expansion) is practiced. (Fig)
Marble chips
- flooring thickness shall not be less than 20 mm and does not exceed 50 mm
- chips shall be irregular shape and the smallest dimension shall not be less than
100mm

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 49

 - the exposed surface of mortar finish to marble chip shall not exceed 1:3
proportion
Ceramic and mosaic tiles
- ceramic tiles shall be glazed type of approved color , texture and size
- ceramic tiles shall be 6mm thick for walls and not less than 15mm for floors
- mosaic tiles shall be in regular square or hexagonal sizes not exceeding 25mm in
dimension of each size
PVC tiles
- usually thermoplastic
- the tiles and skirting shall be resistant to household oil and acids
- the glue (adhesive ) for fixing PVC tiles and skirting shall be in accordance with
manufacturer‟s instruction
- usually 2mm thick PVC tiles and 48 mm cement screed is used

COPPING, CILLS, STEPS, RISERS

- can be from marble , terrazzo , concrete , stone etc and shall be laid as per the
drawing

Stone and concrete pavements

- dressed or roughly dressed sand stone or precast concrete shall be laid on
compacted fill of 10 mm sand or red ash bedding and joints pointed with cement

Method of measurement
The following shall be measured by area specifying material, size and thickness
- all finishes to floors and walls except skirting , copping and cills
- all finishes to risers , treads, and landings to stairs
The following shall be measured in length specifying material, size and thickness
- skirting, cills and copings, dividing strips in floors
The following shall be understood as included:
- preparing background, hacking , raking , grouting , bedding , jointing , rubbing
and priming
4.3.11 GLAZING

Transparent glass
Sheet glass (clear glass)
Transparent glass shall be clear or tinted, transmitting light and capable of showing
objects

Figured glass
- have sufficient imprinting of texture or pattern totally or substantially obscure
vision

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 50

Opal glass
- vision from inside but not from outside

Wired glass
-shall be in wire mesh , transparent , translucent or figured

Putty
- used for fixing the glass to the frame
- shall be quick , hard setting, tropical putty specially manufactured for glazing
works

METHOD OF MEASUREMENT
- glazing shall be measured by area
- glazing to louvers and special fixing may be enumerated by stating size and
thickness
The following shall be understood as included: -
Bedding, mastic, fixing, beading, cleaning etc

4.3.12 PAINTING WORKS

Oil based priming paints
(priming coat – initial or preparatory coats )
- applied to surfaces readily mixed or base paints

Aluminum priming paints

- for wood work
- shall be for brush application

Metallic zinc rich priming paints

- shall be applied to iron and steel surfaces

OIL PAINTS
- water proof
- shall be applied in accordance with manufacturers instruction
- can be applied for walls, wood work , metals

PLASTER EMULSION PAINTS

- normal and usual type of painting
- shall be selected for interior and exterior works

SYNTHETIC ENAMEL PAINTS

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 51

 - used for metals with manufacturers instruction

METHOD OF MEASUREMENT
- painting shall be measured by area
- special application to edges shall be measured in length stating the girth
- internal and external surfaces shall be measured separately
The following shall be understood as included
- Trimming, cutting, matching patterns, cleaning, priming

4.3.13 SANITARY WORKS

It includes all works on building in connection with supply of potable water and
removal of solid and liquid wastes
CLASSIFICATION OF SANITARY INSTALLATIONS
Pipes
- Galvanized steel pipes –used for distribution of water (pipes for cold and hot
potable water internally and externally installed having plain or threaded ends.
- Pipes are measured by length stating diameter taken along the centerline over all
fittings
- How are distribution pipes indicated in drawings?
(Fig - Riser diagrams)
Valves:
- Flanges used to connect pipes and for controlling
- Check valves, gate valve, service valves
- shall be in specified material and size at positions indicated in drawings
- Enumerated stating diameter
UPVC (unplasticised pvc ) – rigid thermoplastic conduit
- can be used for cold water distribution
- usually used for solid waste and surface drainage with vent pipe in horizontal and
vertical stacks
- shall be measured in length stating diameter and understood to include accessory
joint fitting like Y,T, joints
Precast concrete pipes – for solid waste and surface drainage
Solid pipes –surface drainage and sewage
Perforated pipes – subsurface drainage
Manholes: - shall be in precast concrete C 20 quality or class A hollow brick as
indicated and detailed in the drawings.(Fig)
- shall be laid on a minimum concrete bed of 150mm
- enumerated stating size and depth including all related earthwork
Manholes are used for inspection, reduction of number of pipes, change of directions
at angles
Trench excavation and cutting

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 52

 - carried out after full supply of pipes has been made
- bottom excavations trimmed and level to the requirements
- minimum width for pipes of 200 mm is 600 mm and not less than 600.
- greater than the diameter of the pipe for pipe sizes over 1000mm
Pipe laying checked for true straight, and gradient shall be given concrete bed or
granular bed
a) concrete bed (fig)
b) granular bed - max grain size 20mm
- the granular fill and concrete in layers not exceeding 20 cm
- no mechanical compactor is used upto 1000mm above the fill for granular
and 600 mm for concrete bed
Concrete pipes shall be measured in length, stating the diameter and understood as
including: setting out, trench excavation, pipe laying, jointing, bedding and backfills

SEPTIC TANKS, SOAKAWY PITS AND PERCOLATION DITCH

Solid and liquid waste _(concrete) pipe _(manhole) _septic tank
- Measurement shall be done in accordance with the method of measurement for
each item of works
- May be specified on lump sum for costing

SANITARY FIXTURES
- Shall be manufactured of standards acceptable for the intended purpose
- Appliances shall be supplied with mounting and plugging devices, valves, chains,
waste plug, traps, handles, flexible pipes, bolts, nuts screws, hinges etc
- WC units – they are of different types
White Vitreous China WC
- Low flush cistern, plastic seat and cover, inlet and drain connecting and complete
with fixing devices
- Ditto as above but high flush cistern
Enameled White Cast Iron Pedestal Pan WC unit
- Concealed flush and cistern, plastic seat and cover, inlet and drain connector, trap
and complete with fixing devices
- ditto as above but high flush cistern
Precast terrazzo squatting pan WC unit with high level flush cistern, inlet and drain
connector, trap and complete with fixing devices
WC units are enumerated items
HWB (hand wash basin)
- white vitreous china, standard white wash hand basin of specified size , with pair
of white painted cast iron screw to wall , brackets 32 mm slotted basin waste and
overflow, chromium plated basin chain and rubber plug , 32 mm chromium plated

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 53

 bottle trap and connector , flexible pipe connector, complete with fixing devices ,
and chromium plated cold water valve only .
- ditto as above but chromium plated cold and hot water valves .
Urinals: white vitreous china urinal bowel supported on concealed wall hangers, 9 litre
capacity level cistern with automatic siphon, flexible pipe connector, drip tap,
stainless steel exposed flush pipes, 38mm waste strainer and bottle trap
- Ditto as above but with two unit divisions
Shower units, water heaters and sinks are fixtures
Other accessories
Toilet roll, soap dish, towel rail
Method of measurement – enumerated stating size

4.3.14 ELECTRICAL INSTALLATION

It includes supply, erection, installation, testing and commissioning of electrical wares as
generally shown on electrical drawings
- Materials shall be fully in accordance with qualities, tolerances, tests,
recommendations, method of workmanship as described on specification
All accessories shall be fixed at the following heights above finished floor level unless
specified on the BOQ or drawings
- Distribution boards 1700 mm
- Lighting switches and push buttons 1400 mm
- Lighting switches and push buttons above beds 1000mm
- Sockets in general 300 mm
- Sockets on benches 1500 mm above bench top
- Sockets in workshops 1100mm
- Telephone outlets 300mm
- Bells 2100 mm
1) Underground cable ducts
- made of precast concrete pipes or galvanized steel pipes
- for protection of power and telephone outlet cable
- it shall be the responsibility of the contractor to ensure that the underground duct
is installed correctly according to each party‟s requirement
- precast concrete , galvanized steel upvc are used (similarly as given for sanitary
installation)
- Manholes – similar to the requirements for sanitary installation
2) Distribution boards (DB)
Main distribution boards (MDB) and sub distribution board (SDB)
- The contractor shall supply and install medium voltage MD panel as shown on the
drawings. Arrangement of the panel shall be as to permit the ready incoming and
outgoing cables.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 54

 - Sub distribution board (SDB) shall be surface flush mounted and DB shall be of
the type fully enclosed sheet steel cabinet and hinged cover
- DBs shall be enumerated stating the power and voltage supply including all
related works
3) PVC cables – underground cables shall be pvc insulated steel wire and pvc served
overall and all cables shall have copper conductors
- measured in meter linear

4) Light points, power and socket outlets

- outlets are either of bell, fan , telephone , TV or antenna
- outlets shall be enumerated and understood as including all related works
Light points
- Fed through specified size pvc insulated conductors of thermoplastic conduits of
13.5 mm diameter for surface installation including junction boxes with cover and
insulating caps
- Ditto as above but in steel conduits of 15 mm diameter
Socket outlets – same as light points
Bell points - fed through pvc insulated conductor of 2mm by 0.8 mm2 inside
thermoplastic conduits including junction boxes with covers
Fan outlets – fed through pvc insulated conductors inside thermoplastic conduits of
13.5 mm upto 16mm diameter for surface installation thermoplastic conduit is used
for recessed or internal surface installation
Power outlets –ditto as above
Telephone outlets – ditto as above but wiring done by ETA
Measurement: - enumerated and understood to include related works
TV antenna outlets
- 20 mm diameter thermoplastic conduit for recessed installation
- 20mm rigid thermoplastic conduit for surface installation
- 20 mm steel conduit for surface installation
outlets are enumerated and understood to include chiseling , laying conduits and
installing wires providing junction box and insulating cups

Electrical fixtures
- Light fixtures –shall be enumerated stating type of fixtures
- Air conditioners
- Fans, Bell systems
- Shall be enumerated stating type of fixture

C. EXTERNAL WORKS, SERVICES (SITE WORKS)

- maintenance
- pavements

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 55

 - parking
- landscaping and gardening
- fencing
Excavation and earthworks for slope stabilization or drainage ditches

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 56

 CHAPTER FIVE

COST ESTIMATION

General
Project cost estimation is the process of valuing on monetary expression, including the
cost of all possible entrants necessary for the planning, implementing and monitoring
stages of the proposed project under consideration. If the available financial capacity is
smaller than the estimated cost, it is important to redefine the scope of the work by either
changing the specification or size of the work. The possible entrants of project cost are:
- Preliminary investigation (project appraisal costs)
- design and supervision (consultancy cost )
- construction works (contractor‟s cost )
- land owning cost
- monitoring costs

Purposes of Estimation
The main purposes of costing or estimating are to:
- know the volume of work in reference to the fund available
- determine actual cost per unit of item
- identifying engineering estimate of the work for bidding purpose
- work out economical use of materials , labor and equipments
- in cases of variations to determine the extra cost to be incurred
- when changes in cost due to legislation happens, to work out the escalation in
cost
Factors affecting cost estimation
1) Type and documentation of the project
2) Construction scheduling
3) Bidding environment
4) Quality and availability of material and labor (given in specification)
5) Strength or grade required. Eg. C15, C20, C25 concrete
6) Construction facilities /tools and method of construction
7) Location of the site
8) Transportation charges
9) Proper management
10) Land charges (lease)
11) Nature of subsurface condition (and the foundation that is being used)

The following information is required to define cost per unit of work

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 57

 1. Correct information of the market price of the materials at the time of need to be
used as a prime cost
2. Correct information of the rates of various categories of skilled and unskilled
laborers as wage rates to be used for daily work rate
3. Output of laborers per day for various types of items (productivity)
4. Correct information of the rates of various categories of equipments and tools as
rental rates to be used for major items of rates
5. Up-to-date knowledge of the construction methods.

Types of costing or estimating

Estimation can be broadly classified as preliminary (approximate) and detailed
(refined). But it is also possible to classify estimation into four categories as follows:

1. Preliminary /approximate costing

This type of cost estimation is required to know the financial position of the client before
costly detailed designs are carried out. Such estimates are based on practical knowledge
and cost of similar previous works. Examples of approximate cost estimations are as
follows:

Cost per functional unit

Hospital =cost per bed, Dormitory = cost per student, Cinema or theatre = cost per seat,
road works = cost per kilometer length, etc

Plinth area method – cost per m2 of a building

(Plinth area means built up (covered) area measured at floor level of the storey)
Social Buildings – not aesthetic but functional, 1000 – 1500 Br/m2
Industrial Buildings – Profitable but aesthetics is not the main quality, 1300 – 2000Br/m2
Monumental Building – Aesthetics is the main quality, eg. Palaces, museums
2000 – 3000Br/m2

Cubical Content method – cost per m3 of the building

Elemental/parametric Estimate – roughly grouped quantities or elemental bill

In this approach the project is first divided into functional systems/elements and rough
quantities are taken off. The cost of each element is obtained by multiplying the
quantities obtained by established unit prices, and the elemental costs are added to get the
total construction cost.
Example: Slab =.....Br/m2
Beam (Specified size) = .....Br/meter linear

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 58

 2. Detailed estimate or item rate method
This is the most reliable and accurate type of estimate. The quantities of items are
carefully prepared from the drawings and the total cost worked out from up to date
market rates. Detailed estimate is accompanied by a detailed report, detailed specification
for the execution of the work, and detailed drawings, etc.
3. Revised Estimate
A detailed estimate prepared afresh when the original detailed estimate is beyond an
acceptable range. It should be accompanied by all the papers as in the case of the detailed
estimate and also should include the comparative statements of variations in each item of
works.
4. Supplementary Estimate
When additional works are there, a fresh detailed estimate is prepared to supplement the
original work.

5. Rate Analysis
Rate Analysis is the process of fixing cost per unit of measurement for the different item
of works. Cost due to construction (contractor‟s cost) is given special attention here.
Total cost per unit of work (TC) may be grouped into two components; direct cost and
indirect cost. The direct cost (DC) includes cost due to material, cost due to labor, cost
due to equipment, whereas the indirect(IC) cost covers overhead costs, and contractor‟s
profit. Overhead costs are expenses for general office facility, rents, taxes, electrical light,
water, and other miscellaneous items.
In order to facilitate estimation of cost due to material, it is important to know the
quantities of various materials involved in construction of various parts of the building or
construction work i.e. material break down is essential.

Material Breakdown
1. Quantity of materials required for brick masonry laid in 1:4 cement mortar
Qty of brick masonry =1m3 (4m2 for 25cm thick brick wall)
Size of one brick =24x12x6 cm (common in Ethiopia)
Size of one mortared brick= 25x13x7 cm;
Volume of each mortared brick = 0.25x0.13x.07 = 2.275x10-3m3
Number of bricks required =1/ 2.275x10-3m3 = 440 mortared bricks per m3
Add 2% for breakage =9
Take 450 bricks per m or 450/4 = 112.5 bricks/ m2; take 115 bricks/ m2
3

Volume of one nominal (unmortared) brick = 0.24x0.12x0.06 = 1.728x10-3m3

Volume of 440 unmortared bricks = 440x1.728x10-3m3 = 0.76032m3
Volume of wet mortar in 1m3 of wet masonry = 1 - 0.76032 = 0.23968m3

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 59

Percentage of wet masonry in 1m3 masonry work = (0.23968/1)*100 = 23.96%
(can be taken as 25%)
Factor of conversion of wet mortar into dry mortar (quantity for dry base analysis)
Volume of wet mortar in 1m3 of wet masonry = 0.23968m3
Add 10% for wastage = 0.023968m3
Sum Total = 0.263648 m3
Assume 20% voids in sand (Note that cement fills the voids b/n sand particles)
Volume of dry base analysis = wet mortar volume + increment because of voids in sand
= 0.263648 m3 + 20/100* 0.263648 m3
= 0.31638m3 ; nearly 30% of the volume of construction
Factor of conversion = volume of material required on dry base/ volume of wet mortar
= 0.31638m3 / 0.263648 m3 =1.2
Cement mortar of 1:4 mix by volume (1+4 =5)
Qty of cement required = 1/5 * 0.316 = 0.0632m3/m3 of construction
Number of bags of cement = 0.0632m3/ 0.035 m3per bag =1.81 bags per m3 of
construction; 1.81/4 = 0.45 bags per m2
Qty of sand required = 4/5 * 0.316 = 0.253m3 per m3 of construction = 0.063m3/m2
Exercise: define qty of materials required to construct 1m2 HCB wall laid in 1: 4 cement
mortar; Take nominal size of blocks as 40x20x20 cm, 40x20x15cm, or 40x20x10 cm.

2. Quantity of materials required for C -25 cement concrete (1:2:3)

Cement concrete is a heterogeneous mixture of cement, fine, and coarse aggregates;
cement fills the voids in sands also while sand fills the voids in the coarse aggregate.
Water acts as an agent so that the paste of cement can coat all the particles of the
aggregate. The hydration of cement results in solidification of entire mass and thus binds
the different particles together. Because of the voids in aggregates and wastage, 1.4 to 1.6
times dry volume of the materials are required to get 1m3 of compact dense fresh
concrete mix.
Materials required for 1:2:3 cement concrete mix – a commonly used grade of concrete
for structural works.
Wet (fresh) concrete mix …………= 1m3
Quantity for dry base analysis…….= 1.5*1.0m3 = 1.5m3
Volume of cement……………= 1/6*1.5 = 0.25m3 = 0.25m3/0.035m3 per bag
= 7.1 bags of cement
3
Sands ………………………..= 2/6* 1.5 = 0.5m of sand
Coarse aggregate…………….= 3/6 *1.5 = 0.75m3 of coarse aggregate

Exercise: Do similarly for C 20 and C 30 concretes

3. Quantity of Materials required for stone masonry laid in 1:3 cement mortar

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 60

Quantity of stone masonry work ….= 1m3
Quantity of undressed stone ………= 1.1m3 (taken 110%)
Quantity of mortar required……….= 0.35m3 (taken 35%)
Quantity of cement ………………. = 1/4 *0.35 = 0.0875m3 = 0.0875/0.035 = 2.5 bags
Quantity of sand required …………= 3/4 * 0.35 = 0.263m3

4. Materials required for 12mm thick cement plaster in 1: 4 cement mortar

30% more mortar is required to fill up joints and uneven surfaces. This total wet mortar is
increased by 20% to convert to dry mortar (for the effect of voids). Thus, wet mortar is
multiplied by 1.55 to define quantity of material required on dry base.
Area to be plastered = 1m2
Thickness of plaster = 12mm
Volume of the mortar = 1*0.012 = 0.012m3
Volume for dry quantity = 1.55 * 0.012 = 0.019m3
Cement required = 1/5 * 0.019 = 0.0038m3 = 0.11 bags of cement
Sand required = 4/5 * 0.019 = 0.015 m3

5. Materials required for pointing in cement mortar of 1:2

Area to be pointed = 1m2 [total wall area]
In 1m2 wall area, number of mortared bricks of 25x13x7cm size (assuming 25cm thick
double brick wall) = 1/(0.25*0.07) = 57
Face area of the 57 nominal bricks = 57*0.24*0.07 = 0.82m2
Area covered by joints (pointed) = 1 – 0.82 = 0.18m2
Average thickness of pointing = 20mm
Volume of wet mortar = 0.02*0.18 = 0.0036m3
Volume for dry quantity = 1.55* 0.0036 = 0.006m3
Cement required = 1/3 *0.006 = 0.002m3 = 0.05 bags
Sand required = 2/3 * 0.006 = 0.004m3

Exercise: Do similarly for tiling works using mortars

Calculation of Unit Price (rate)

I. Cost per m2 of 25cm thick brick masonry wall, laid in 1:4 cement mortar
Total cost (TC) = Direct cost (DC) + Indirect cost(IC)
IC = 25% to 35% of DC; Equipment cost (EC) = 5% to 10% of TC
1. Material cost
Brick: Purchasing Cost + loading Cost + unloading Cost
= 115 pc*0.85Br/pc + 115(50Br/1000pc) + 115(350Br/3000pc) + 115(80Br/1000pc)
= 126.12Br/m2
Cement: Purchasing Cost + loading Cost + unloading Cost

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 61

 (Provide 10% allowance for wastage by wind, = (1.81/4)*1.1= 0.5 bag/m2)
= 0.5 bag/m2*55Br/bag + 1Br/bag* 0.5bag + 2Br/bag* 0.5bag + 1Br/bag* 0.5bag
= 29.5 Br/m2
Sand: Purchasing Cost + loading Cost + unloading Cost
= 0.063m3/m2 *120Br/m3 = 7.56 Br/m2
Total material cost = cost of (brick +cement +sand)
= 126.12 + 29.5 + 7.56 = 163.18 Br/m2
2. Labor cost (LC)
Crew = a group which is directly involved in a similar job
A crew for brick masonry work consists of a mason, an assistant mason and two labors
Utilization Factor (UF) = 1/ the # of crew or people under supervision
Forman, to guide/control masonry work, UF = ¼, when controlling four crews
Site Engineer/Manager, UF = 1/10 (assumed to control 10 formen)
Indexed hourly wages
Site Engineer/Manager 4000Br/month = 4000Br/(22days*8hrs/day) = 22.70Br/hr
For a utilization factor of 1/10 (for 10 formen under him)
= 22.70*1/10 = 2.27Br/hr
Forman daily wage = 40Br/day = 40/8*(1/4) = 1.25 Br/hr, for 4 crews
Mason daily wage = 30Br/day = 3.75Br/hr , UF = 1
Assistant mason daily wage = 20Br/day = 2.5 Br/hr, UF = 1
Daily laborers, daily wage = 10Br/day =1.25Br/hr, UF = 1
Labor out put (productivity) for the work = 4m2/day = 0.5m2/hr
Labor cost (LC) = Cost per unit time/ productivity
= [2.27 + 1.25 + 3.75 + 2.5 +2*1.25] Br per hr / [0.5 m2per hr]
= 24.54Br/m2
DC = MC + LC +EC; take EC = 0.05TC
DC = 163.18 + 24.54 +0.05TC; but TC = DC + IC, take IC = 0.25DC; thus
TC = (187.72 + 0.05TC) + 0.25DC
TC = (187.72 + 0.05TC) + 0.25(187.72 + 0.05TC
TC = 234.65+ 0.063TC
TC = 250.30Br per m2
Thus, the unit price for 25cm thick brick masonry wall laid in 1:4 cement mortar is
estimated to be 250.30Br/m2
Exercise: Similarly fix unit price for HCB masonry walls laid in 1:4 cement mortar
making use of most recent market prices.

II. Unit price for C -25 concrete per m3 of work (formwork and reinforcement m/s)
Material cost
Cement = 7.1bags/m3* 50Br/bag = 355Br

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 62

Sand = 0.5m3*120Br/m3 = 60 Br
Coarse Aggregate = 0.75m3*120Br/m3 = 90 Br
MC = 505 Br/m3
Labour cost
The crew consists of a mason, two assistants, and four daily laborers at the wage rates
given above for brick masonry work.
Site Engineer/Manager 4000Br/month = 4000Br/(22days*8hrs/day) = 22.70Br/hr
For a utilization factor of 1/10 (for 10 formen under him)
= 22.70*1/10 = 2.27Br/hr
Forman daily wage = 40Br/day = 40/8*(1/4) = 1.25 Br/hr, for 4 crews
Mason daily wage = 30Br/day = 3.75Br/hr , UF = 1
Assistant mason daily wage = 20Br/day = 2.5 Br/hr, UF = 1
Daily laborers, daily wage = 10Br/day =1.25Br/hr, UF = 1
Labor output (productivity) for the work = 2m3/day = 0.25m3/hr
Labor cost (LC) = Cost per unit time/ productivity
= [2.27 + 1.25 + 3.75 + 2*2.5 +4*1.25] Br per hr / [0.25 m3per hr]
= 69.08Br/m3
DC = MC + LC +EC; take EC = 0.05TC
DC = 505+ 69.08 +0.05TC; but TC = DC + IC, take IC = 0.25DC; thus
TC = (574.08 + 0.05TC) + 0.25DC
TC = (574.08 + 0.05TC) + 0.25(574.08 + 0.05TC)
TC = 717.6+ 0.063TC
TC = 765.8Br per m3

Exercise: Revise the above unit price making use of the most recent market condition for
all factors affecting the cost.

Compiled by Kassahun A. (Msc) AMIoT, civil engineering dep. 63