CSQS ch 1, 2& 3 lec. note.pdf

Mekelle University Ethiopian Institute of Technology-Mekelle SOCE/CoTM Chair
Contract, Specification and Quantity Surveying Lecture Note Prepared by: D.T,F.G, K.B & A.E Page 1
1. INTRODUCTION TO CIVIL ENGINEERING DESIGN AND CONSTRUCTION PROCESS
1.1. Types and characteristics of Civil Engineering Projects
In the planning of Civil Engineering projects/facilities, it is important to recognize the close relationship
between design and construction. These processes can best be viewed as an integrated system.
Broadly speaking, design is a process of creating the description of a new facility, usually represented by
detailed plans and specifications; construction planning is a process of identifying activities and resources
required to make the design a physical reality.
Hence, construction is the implementation of a design envisioned by architects and engineers. In both
design and construction, numerous operational tasks must be performed with a variety of precedence and
other relationships among the different tasks.
Several characteristics are unique to the planning of constructed facilities and should be kept in mind even
at the very early stage of the project life cycle. These include the following:
 Nearly every civil engineering project(facility) is custom designed and constructed, and often requires
a long time to complete.
 Both the design and construction of a facility must satisfy the conditions peculiar to a specific site.
 Because each project is site specific, its execution is influenced by natural, social and other locational
conditions such as weather, labor supply, local building codes, etc.
 Since the service life of a facility is long, the anticipation of future requirements is inherently difficult.
 Because of technological complexity and market demands, changes of design plans during construction
are not uncommon.
Keeping in mind the above unique Characteristics, civil Engineering projects can divide based on by its
features of output, its size, government as a main client, nature of demand for construction output, nature
of construction work, variety of construction technology, and structure of industry. Feature of construction
output are durable or long-lasting output, large and heavy units, unique, immobile, complex process, and
expensive.
Since most owners are generally interested in acquiring only a specific type of constructed facility, they
should be aware of the common industrial practices for the type of construction pertinent to them. Likewise,
the construction industry is a conglomeration of quite diverse segments and products.
Some owners may procure a constructed facility only once in a long while and tend to look for short term
advantages. However, many owners require periodic acquisition of new facilities and/or rehabilitation of
existing facilities. It is to their advantage to keep the construction industry healthy and productive.
Collectively, the owners have more power to influence the construction industry than they realize because,
by their individual actions, they can provide incentives or disincentives for innovation, efficiency and

quality in construction. It is to the interest of all parties that the owners take an active interest in the
construction and exercise beneficial influence on the performance of the industry.
In planning for various types of construction, the methods of procuring professional services, awarding
construction contracts, and financing the constructed facility can be quite different. For the purpose of
discussion, the broad spectrum of civil engineering projects/facilities may be classified into four major
categories, each with its own characteristics.
1. Residential Housing Construction
Residential housing construction includes single-family houses, multi-family dwellings, and high-rise
apartments. During the development and construction of such projects, the developers or sponsors who are
familiar with the construction industry usually serve as surrogate owners and take charge, making necessary
contractual agreements for design and construction, and arranging the financing and sale of the completed
structures. Residential housing designs are usually performed by architects and engineers, and the
construction executed by builders who hire subcontractors for the structural, mechanical, electrical and
other specialty work.
The residential housing market is heavily affected by general economic conditions, tax laws, and the
monetary and fiscal policies of the government. Often, a slight increase in total demand will cause a
substantial investment in construction, since many housing projects can be started at different locations by
different individuals and developers at the same time. Because of the relative ease of entry, at least at the
lower end of the market, many new builders are attracted to the residential housing construction. Hence,
this market is highly competitive, with potentially high risks as well as high rewards
2. Institutional and Commercial Building Construction
Institutional and commercial building construction encompasses a great variety of project types and sizes,
such as schools and universities, medical clinics and hospitals, recreational facilities and sports stadiums,
retail chain stores and large shopping centers, warehouses and light manufacturing plants, and
skyscrapers for offices and hotels. The owners of such buildings may or may not be familiar with
construction industry practices, but they usually are able to select competent professional consultants and
arrange the financing of the constructed facilities themselves. Specialty architects and engineers are often
engaged for designing a specific type of building, while the builders or general contractors undertaking
such projects may also be specialized in only that type of building.
3. Infrastructure and Heavy Construction
Infrastructure and heavy construction includes projects such as highways, mass transit systems, tunnels,
bridges, pipelines, drainage systems and sewage treatment plants. Most of these projects are publicly
owned and therefore financed either through bonds or taxes. This category of construction is characterized
by a high degree of mechanization, which has gradually replaced some labor-intensive operations. The

engineers and builders engaged in infrastructure construction are usually highly specialized since each
segment of the market requires different types of skills.
4. Specialized Industrial Construction
Specialized industrial construction usually involves very large-scale projects with a high degree of
technological complexity, such as oil refineries, steel mills, chemical processing plants and coal-fired or
nuclear power plants. The owners usually are deeply involved in the development of a project, and prefer
to work with designers-builders such that the total time for the completion of the project can be shortened.
They also want to pick a team of designers and builders with whom the owner has developed good working
relations over the years.
Although the initiation of such projects is also affected by the state of the economy, long range demand
forecasting is the most important factor since such projects are capital intensive and require considerable
amount of planning and construction time.
1.2. Design and Construction Process
In general, when a construction project is initiated, a Facilities Planning and Construction project manager
is assigned to the project, and a design team committee is formed to oversee the project development until
completion. The life cycle of a construction project involves the following phase
Civil Engineering Projects phases
These phases are common to all new construction and renovation projects; however, in smaller projects,
the phases often become less formal, involve fewer individuals and may have a short schedule of only a
few months. Large projects, on the other hand, may take years from the time they are envisioned to the
time "move in" takes place.
The following describes each phase of a large project:
Programming: -under this stage the planning team is formed to represent the stakeholder and
intentions/need with the project. The team will be responsible for making the necessary design decisions
based upon user requirements and develop the specific requirements for the project called a Terms of

Requirements (TOR) which includes that details all objectives, spaces, services, equipment (new and
existing), special finishes, furniture and spatial relationships. The TOR forms the basis of the
client/Employer expectations and goals for the completed project in professional way.
In the case of technically complex projects, an outside consultant may be engaged to prepare the program
documents.
Design professionals are generally firms offering both architectural design and engineering services.
However, on occasion, design firms join with engineering firms to form a design team.
The successful design firm uses the program of requirements, institutional standards for design and
construction, the schedule and the construction budget, as well as any other applicable requirements, as the
basis for their design.
Schematic Design: -The first step by the design team is referred to as the “schematic design" phase, in
which the objective is the development of simple diagrammatic documents delineating capacity like room
sizes and relationships, single line diagrams of all systems, preliminary design studies of the structure
exterior, and, if applicable, drawings of special interior spaces. The schematic design will be reviewed
during frequent meetings with the design team of different professionals of built environment. At the
conclusion of this design phase, the Architect/Engineer will submit drawings, a project narrative and an
estimate of construction cost for review and approval by the financer and/or Employer/Client representative
Design Development: -The approved schematic design is then further developed into definitive plans and
elevations by the design team. Colors, patterns, materials, lighting fixtures, and special equipment and
building elements are selected and reviewed with the financer and/or Employer/Client representative. For
complex projects, detailed plans identifying all services, casework and equipment are also developed.
Detailed floor plans, sections, elevations and an outline specification defining materials, finishes and
systems, as well as an updated construction cost estimate, are submitted for review and approval by the
financer and/or Employer/Client representative.
Construction Documents: -The approved definitive design documents are developed into comprehensive
construction drawings and specifications that are used to secure a building permit, if required, to
competitively bid the work and ultimately as the basis for the construction of the project. The construction
documents are submitted for review and approval by the financer and/or Employer/Client representative.
After a thorough review and evaluation of all the bids by financer and/or Employer/Client representative,
the most responsive, responsible, low bidder who meets all the requirements of the bid documents is
selected and recommended to the financer and/or Employer/Client for approval.
Construction: - The project manager coordinates the work, monitors costs and scheduling, and reviews
the construction work performed by the contractor. The project manager will also keep the designated
different stakeholder representative informed of the progress of the project.

Any user requesting changes to the project must be directed in writing to the project manager/Resident
Engineer(RE). The project manager will address these requests appropriately within the guidelines
established prior.
Pre-occupancy/Commissioning: - The RE arranges for contractors to provide training for Operations
personnel and others who will be responsible for operating and maintaining the facility. Operations assume
operational responsibility for the facility at the time of occupancy.
This will include an explanation of how the facility is zoned for thermal comfort, operation of appropriate
facility components, the location of emergency equipment and exits, etc. The operational and maintenance
responsibility for the facility is turned over to Operations at this time.
Generally, Design Sequence
1.3. Relationship between Construction Documents
The construction documents define the quantities and qualities of, and relationships among, all materials
required to construct a project; they establish the contractual obligations for the client and the contractor,
and they define the roles of the construction team members.

Construction “Contract Documents” are the written documents that define the roles, responsibilities, and
“Work” under the construction Contract, and are legally-binding on the parties (Owner and Contractor).
For this course construction documents can be classified in to three main parts like Technical part, legal par
and commercial part. The last two parts will be discussed in detail in chapter 4 and 5.
A set of complete construction technical documents is made up of two to three components.
The largest component is the set of working drawings. The set can range from a single sheet to potentially
hundreds of sheets, and can include drawings that address the architecture, interiors, plumbing, mechanical
systems, structural, and landscape designing for the project.
Another component commonly included in a set of construction technical documents is the specifications.
The specification with the scope of work(BOQ) is a written project manual that covers products, materials
and methods to be used in constructing the project.
Since the construction technical documents become part of the legal construction contract, it is extremely
important to produce complete and accurate documents.
For all measurements to determine the scope of project works(BOQ); drawing and specifications are main
guiding documents in addition to related raw data of the site condition like survey, geotechnical
investigation and other data’s.
The information necessary for construction of a facility is developed from the design process by the
Architect/Engineer is presented by the Contract working Drawings and the Contract Specifications. These
two types of documents are a means of communicating information between the Architect/Engineer and the
Contractor, but each type uses special forms of communication. One is pictorial or graphic, and the other is
verbal or textual. Despite these distinctions, each type of document should complement while not
contradicting or duplicating the other. In this way, each type of document fulfills its unique function.
Both drawings and specifications are needed to understand the requirements of the Work under the Contract
and the intent of the design for the project.
The Construction Drawings
The Drawings are the graphic and pictorial portions of the Contract Documents showing the design, location
and dimensions of the Work, generally including plans, elevations, sections, details, schedules and
diagrams.
This information is best described graphically on the drawings which cannot be effectively conveyed by
words alone. Drawings should indicate the relationship between elements of the facility and may designate
the following for each material, assembly, component, and accessory:
 Location of each material, assembly, component, and accessory.
 Identification of components and pieces of equipment. Use only generic names and locations, and
coordinate terminology used on Drawings and in Specifications with short keynotes.

 Give dimensions of components and sizes of field-assembled components.
 Indicate interfaces and connections between materials, detail assemblies, and diagram systems. Indicate
boundaries between materials of different capacities.
 Show forms and relationships of building elements.
 Indicate limits of Work and, as applicable, indicate areas of construction phases.
 Indicate extent of alternates and indicate “base bid” and “alternate bid” construction so that the scope
of each condition is clear.
 Indicate work to be performed by or for the Owner under separate contracts.
 On multiple-prime contract projects, indicate locations, limits, and extent of the Work included in
separate contracts and detail interfaces between scopes of Work.
 Identify applicable Drawing symbols in a schedule of symbols.
Well-prepared Drawings:
 Should not use comprehensive or too many notes. Redundancy should be avoided; concise notes enhance
the clarity of the Drawings.
 Should not use notes that define Work to be performed by a specific subcontractor or trade unless
required by authorities having jurisdiction.
 Should not use proprietary names and slang terms. Instead, use proper, generic terms that are
coordinated with the terminology used in the Specifications.
 Should not cross-reference with specifications by indicating “SEE SPECS.”
The purpose of the Drawings is to convey information regarding the intent of the design and depictions of
Work to be accomplished.
Shop Drawings—All drawings, diagrams, illustrations, schedules, and other data or information that are
specifically prepared or assembled by or for Contractor and submitted by Contractor to illustrate some
portion of the Work.
N.B. Shop Drawings, whether approved or not, are not Drawings and are not Contract Documents.
The Specifications
One of the key performance measuring criteria of any construction project success is quality which measures
the conformance of the project to the agreed requirements. This agreed requirement of the customer is
basically stated using specifications and drawings. Specifications are defined as follows:
 It is the statement of the particular needs to be satisfied, or essential characteristics that a customer
requires (in a good, material, method, process, service, system, or work) and which a contractor must
deliver.
 It is the 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. In terms of
an engineering project a specification contains a detailed written description of the quality of materials
and workmanship necessary to complete the work.
Specifications provide a comprehensive written description stipulating “how” the work is to be
accomplished and the results required. Drawings present a picture of “what” work is required and when
combined with the specifications are expected to describe a project in sufficient detail for bidding and
construction. The Specifications are that portion of the Contract Documents consisting of the written
requirements for materials, equipment, systems, standards and workmanship for the Work, and performance
of related services.
A civil engineering specification is read in conjunction with drawings and a bill of quantities to supply the
contractor with all the information needed to submit a tender and execute the work.
In broad terms, the Contract Drawings are graphical depictions, and the Contract Specifications are written
descriptions of the end result of the Work to be performed. Each type of Contract Document, whether
Drawings or Specifications, contributes to the overall “story” of construction of a new, remodeled,
renovated, or reconstructed facility.
Specifications should generally describe the following:
 Type and quality of every product in the work, from the simplest material through the functioning system
 Quality of workmanship, including quality during manufacture, fabrication, application, installation,
finishing, and adjusting
 Requirements for fabrication, erection, application, installation, and finishing
 Applicable regulatory requirements, including codes and standards applicable to performance of the
Work
 Overall and component dimensional requirements for specified materials, manufactured products, and
equipment
 Specific descriptions and procedures for allowances and unit prices in the contract
 Specific descriptions and procedures for product alternates and options
 Specific requirements for administration of the contract for construction
Specifications should not overlap or duplicate information contained on the drawings. Duplication, unless
it is repeated word for word, is harmful because it can lead to contradiction, confusion, misunderstanding,
and difference of opinion.

2. SPECIFICATION WRITING
2.1. Specifications Overview
When an Owner decides to build, renovate, or reconstruct a facility, the Owner usually engages others to
prepare documents describing the Work to be performed and the contractual requirements under which
construction and related administrative activities are accomplished. If this documents are properly prepared,
the construction will become successful and cost-effective. To attain this result, appropriate communication
of a project design by the architect/engineer (A/E) to the contractor and other project participants is
mandatory.
Effective communication of the project requirements depends largely on having complete and coordinated
construction documents from project conception, design, construction and commissioning stages. The three
basic types of documents for actual construction are:
1. Bidding and Contract Requirements: Text documents
2. Drawings: Graphic documents
3. Specifications: Text documents
Specifications are the statement of the particular needs to be satisfied, or essential characteristics that a
customer requires (in a good, material, method, process, service, system, or work) and which a contractor
must deliver. It is also the 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. In terms of an engineering project a specification contains a detailed
written description of the quality of materials and workmanship necessary to complete the work.
Construction specifications took on greater importance as a means of communicating design intent and quality
assurance by providing a comprehensive written description stipulating “how” the work is to be accomplished
and the results required. So, knowledge of specification writing principles and procedures is essential to the
specifier in an architectural or engineering firm in order to prepare sound, enforceable construction
specifications. If specification is written properly, the architect or engineer cannot communicate successfully
with the ultimate users of the specifications: facility owners, general contractors, subcontractors, materials
suppliers, code authorities, and quality assurance inspectors.
2.2. The Role of Specifications
Construction specifications are a part of the legal documents of the agreement and form a cornerstone of the
project design. Specifications should be developed alongside the design, increasing in level of detail as the
design progresses. In tender phase, specification should describe every aspect of the building in such a way
that there is no uncertainty about what the contractor is pricing.

The purposes of specifications are basically required to:
 describe the quality and quantity of different materials required for a construction work. This implies,
specification helps the contractor to procure right quality and quantity of material, inspect the quality of
materials by the client and/or consultant, and to avoid dispute.
 specifies the workmanship and the method of doing the work. Thus specification of a work serves as a
guide to a supervising staff of a contractor as well as to the owner to execute the work to their satisfaction.
 govern the cost of a unit quantity of work.
 assist in change order management. This states any change specification changes the tendered rate.
 assists the consultant and/or the engineer in payment certification.
 specify the equipment tools and plants to be engaged for a work and thus enables to procure them
beforehand.
 verify and check the strength of materials for a work involved in a project.
 simplify arbitration and court cases.
A project specification (along with the project drawings) has at least ten different purposes:
1. As a briefing document and a record of
decisions made.
2. As a design record.
3. A demonstration of statutory compliance (Legal
agreement).
4. A cost planning tool.
5. A tendering document.
6. A contract document.
7. A project management aid.
8. An on-site manual.
9. As evidence in disputes.
10. A resource for facilities management and
building maintenance.
Generally, the purpose of construction specifications is to delineate the requirements regarding the materials,
products, installation procedures and quality aspects involved with execution of the work and fulfillment of
the contract. Specification must be accurate. It must not contradict itself or other related documents (drawings,
schedules, other consultant’s documents, standards and codes of practice). It must avoid factual or technical
errors. In fact, in most cases, the construction specifications override the project drawings in the event of
conflicting information.
2.3. Types of Specifications
There are four methods of writing specification. Even though, there is no defined rule for using one method
over another or about combining methods, care should be taken to avoid redundancy or contradictions. The
four method of specifying are described as follow:

1. Proprietary or Brand Name Specifications:
This specification calls for desired materials, producers, systems, and equipment by their trade names and
model numbers. A proprietary specification describes products and materials by manufacturer’s name, brand
name, model number, or unique characteristic.
 For detailed descriptions reference should be made to manufacturer’s specifications.
 They are of two types; closed (sole) source and open or equal source. The primary difference between
the two types concerns substitutions are,
Closed
 Closed specifications generally prohibit substitutions. One or more products are specified, and no
substitutions will be considered.
Open
 Open specifications permit substitutions. One or more products are specified, but other manufacturers
will be considered.
 It is necessary to specify the criteria the alternate manufacturers will be judged by.
2. Performance Specifications:
 Specifies the required results, the criteria by which the performance will be judged, and the method by
which it can be verified. The contractor is free to choose materials and methods complying with the
performance criteria. A performance specification is a description of the required end result of a product
or system and includes the criteria to be used for verification of proper installation. Testing methods and
evaluation procedures for defining the required performances must be explicitly specified. It is generally
written to encourage the use of innovative techniques.
 It is most appropriate when new or unusual products or systems are required.
 It gives suppliers more scope to innovate, and adopt cost effective methods of work, potentially offering
better value for money.
 Typically, performance specifications are written on projects that are straight-forward and are well-
known building types,
 Describing the problems or conditions under which the products or systems must operate, and the
parameters for the acceptable solutions is difficult and challenging.
The general concept behind the performance specification is for the architect or engineer to describe what
they need, and the contractor determine the best way to get there. The performance specification focuses on
the outcome and shifts the selection of materials and methods, as well as a portion of the design work, onto
the shoulders of the contractor. This approach can provide incentives for innovation and flexibility in the

construction approach, but also reduces the amount of control that the architect or engineer has over the
project.
3. Descriptive Specifications:
 Specifies properties of materials and methods of installation without using proprietary names. A descriptive
specification is a detailed description of the characteristics, physical properties, and workmanship required
for the installation of a product or material. It generally requires technical knowledge and experience on
the part of the architect/engineer (A/E).
 It is written for more complex buildings, or buildings where the client has requirements that might not be
familiar to suppliers and where certainty regarding the exact nature of the completed development is more
important to the client.
 The specifier shall take total responsibility for the function and performance of the product.
 It restricts competition and innovation and may relieve the contractor of their liability for 'fitness for
purpose'. Items crucial to the design will be specified prescriptively.
 Generally, this type of specification provides more certainty regarding the final product composition than
the performance specification, and is very frequently used for highly complex portions of a project.
 There are five steps for preparing descriptive specifications:
Research available products
Research the important features required for the product.
Determine which features to describe in the specification and which features to show in the drawings.
Describe the important features.
Specify quality assurance measures (i.e. submittals, certifications, testing or inspection activities)
4. Reference Specifications:
Specifies product or processes by established standards. A reference standard specification uses recognized
industry standards rather than individually written product or installation criteria. Standards must be reviewed
carefully to avoid duplications, optional requirements, and contradictions. These specifications are also used
in conjunction with other types of specifications.
 Steps for preparing reference standard specifications are:
The standard must be recognized as authoritative by the industry.
The standard must be available to all parties involved in the project.
The specifier must know the standard. Assure that the standard relates to the current project and does
not present duplicate or conflicting information.
Establish a date of the standard.
Incorporate the standard correctly into the specifications.
Enforce the requirements of the standard

Both the descriptive and proprietary specification methods are prescriptive; that is, the products and processes
are specified, but not the results. Reference standards are used for prescriptive or performance specifications.
Performance, however, specifies results and not the means to achieve them. Project specifications typically
employ more than one specifying method. All four methods may be used in a single specification section.
There is no clear rule for using either one method or a combination of methods. However, the
architect/engineer (A/E) should be careful about combining methods in the specification of a single product.
This approach can create redundancy or may result in a conflict incapable of resolution.
2.4. Specifications Writing Principles
Specifications provide the written administrative and technical requirements for a construction project and are
a part of the contract documents. They describe the work to be performed, list applicable references, codes,
and standards, dictate the type and quality of materials to be supplied, the methods of construction or required
finished properties, and list the testing and inspection required. This enables both parties (and/or an
independent certifier) to measure the degree of conformance. Knowledge of specification writing principles
and procedures is essential to the specifier in an architectural or engineering firm in order to prepare sound,
enforceable construction specifications.
What constitute the principles of specification writing? Basically, the principles should encompass those
factors that permit architects and engineers to understand clearly the relationship between drawings and
specifications—between the graphic and the verbal—and should enable them to communicate effectively by
setting forth in logical, orderly sequence information to be incorporated into the specifications portion of the
construction documents.
Project specification commonly consists of the following major sections or parts:
 Description of specification coverage
 Materials and fabrication requirements
 Installation or construction requirements
 Testing and quality requirements
2.4.1. Procedures and Practices in Specification Writing
A. Study the Plans
Before beginning to write Specifications for a contract, the Plans should first be studied. It is essential for the
writer to become thoroughly familiar with details of the proposed Work. In studying the Plans, the specifier
should look for unusual site conditions or unusual items of construction. Repeating information that is already
shown on the Plans should be avoided. There should be no discrepancies between the Plans and the
Specifications.
B. Work Closely with the Designer
It is essential that the specification writer work closely with the designer. If the specification writer should
lack any details or information, he/she must not make any assumptions. He/she should request the designer to

supply him with the missing details or information. Knowing the intent or reason for a particular detail on the
Plans will help the specification writer prepare a more realistic requirement for that item of work.
C. Using Standard Specifications
The need for Standard Specifications is understandable; they produce uniformity in the finished product and
at the same time reduce production costs. On the other hand, the use of Standard Specifications may tend to
create complacency on the part of the specification writer and eliminate independent thinking.
When Standard Specifications are being incorporated into a Contract:
1) The specification writer should ensure that the latest published edition of the Standard Specifications and
its complete set of Supplements, are available; and
2) The Standard Specifications and Supplements being incorporated should be carefully reviewed.
Requirements that do not apply to the Contract should be deleted or modified.
D. Utilizing Specifications of Previous Contracts
If a Standard Specification is not being incorporated, the specification writer will most likely select a
Specification from a previous contract involving similar construction, and modify it to suit the needs of the
Contract being specified. this method offers an excellent source of Specification material, provided it fits the
situation.
Finding a Specification for normal items of construction such as roadway excavation, embankment, cast-in-
place concrete, and roadway pavement, generally presents no problem. The problem begins when a
Specification has to be prepared for an item of construction that is infrequently specified, such as cofferdams,
caissons, or tremie concrete. It is, therefore, good policy to compile and maintain a file listing Specifications
prepared for unusual items of construction.
E. Using Reference Standards
Materials should be defined by their reference to national Standards, whenever it is possible. In referring to a
published Standard, its date of issue should not be specified because then the Specification will require
continual updating.
F. Trade Names and "Or Approved Equal"
When there is no established Specification Standard or when a Standard does not specify all of the desired
characteristics, two or more trade names are generally permitted to be used. Three trade names, if available,
are usually preferred by a public agency. Each trade name should be identified with the name of the
manufacturer, model name and number, type, size, and any other classifications that are applicable. If the
manufacturer is not nationally known, his address or the name and address of a local distributor should be
included. Most of this information is usually available from the designer.

When trade names are listed, public agencies generally require the words "or approved equal" to be added
after the listing. This gives other manufacturers and suppliers an opportunity to prove that their product will
also meet the requirements. When using the "or approved equal," it is necessary to spell out the functional
physical and chemical characteristics that are essential to the product's intended end use. Possession of these
characteristics will be the basis for acceptability of a proposed substitution. Otherwise, a contractor may be
tempted to offer a cheaper and inferior substitute in the hope of getting it approved. Approval of an inferior
substitute can expose the Engineer to liability if the approved substitute does not perform.
G. Specifying New Products
The specification writer should be cautious when specifying new products or old products in new applications.
He should seek out the latest information including test literature on the material or product to be specified.
Manufacturers usually publish their product's specifications. Although these specifications should not be
accepted blindly, they can be a starting point in evaluating the product.
The specification writer should obtain from the manufacturer a list of comparable projects on which the
product has been previously used, including names of the owner and designer. The writer should verify its
use record. If untested or untried products lack an adequate experience record, they should be checked out
very carefully.
H. Quality Control and Quality Assurance
Although quality control and quality assurance are both concerned with the quality of materials and
workmanship, they represent two separate and distinct areas of responsibility. Control of quality is the
Contractor's responsibility. He establishes the procedures to control and guide his operations so that they will
produce the desired results. Quality assurance is a function of the Owner's site representative. It is his
responsibility to monitor the work of the Contractor for conformance to the requirements of the Contract.
I. Specifying workmanship
 Determine and specify the quality of fabrication and assembly at the source.
 Determine and specify the quality of field assembly, installation, application, and finishing
2.4.2. Developing Specifications
2.4.2.1.Determining Content for the Specifications
 What Needs to Be Specified? This creates an action item for the designer to follow up on and the specifier
to record on a preliminary list of sections to be written.
 What Are Criteria for Products to Be Specified? Early in the design, criteria need to be identified for:
Configuration Requirements, Material Requirements, Performance Requirements, Code and Regulatory
Requirements, environmental requirements etc.
 What Are Suitable Products?
 What does the Owner or code authority require?
 What method best describes the design intent?

 What method is most appropriate for the project size and complexity?
 What method will result in the best quality of the project?
 What method will result in the best price for the project?
2.4.2.2.Gathering Information
Before beginning to write a section of specifications, the specifier must have the necessary information
pertaining to that product, equipment, system, or assembly. Two kinds of information are needed.
The first is information regarding the specific project requirements that may be obtained from the following:
 Owner’s specific requirements such as mandatory products, standard forms, and standard details
 The A/E design team’s drawings
 A specifications notebook or checklist with recorded product selections by the designer
 A preliminary project description or outline specification prepared earlier
 Applicable laws and building codes
The second kind of information is reference material pertaining to products and construction methods
applicable to the particular specification section. Sources include:
 Manufacturer’s information, including product data available on company web sites, manuals, catalogs,
and other literature.
 Handbooks, pamphlets, and other educational and reference material published by trade associations
whose members are manufacturers, fabricators, and installers.
 Reference standards available from trade associations, government agencies, and national standards
associations.
 Information available from contractors, subcontractors, and special consultants.
 Personal experience of the members of the project team.
 Specifications for similar construction projects where similar products and methods were used.
Caution should be used when referencing similar projects, as products and methods may have changed during
construction and the final record drawings and project notes (i.e., change orders and other work/scope
changes) should also be referenced before using this method. If the required specification information is not
available in office files or catalogs, request assistance from the manufacturer’s representative.
Many manufacturers offer suggested proprietary or guide specifications to relieve the A/E from some of the
tasks of researching and writing a particular specification section. The specifications must be reviewed
carefully to determine whether they have biases and whether they accurately state the necessary information.

2.4.2.3.Product Selection Decisions
It is required systematically and progressively compiling of information, beginning with the early design
phases. Selection is based on evaluation of the products against specific criteria derived from the owner’s
requirements. There are several factors to consider in evaluating a product:
 Product. Determine whether the product is appropriate for the project in all respects, including its
functionality and aesthetics. Determine its physical limitations and compatibility with other products to be
used. Confirm that the product is readily available and to what extent it is warranted. Determine the
product’s life expectancy and its maintenance requirements. Verify that the manufacturer’s state that the
product complies with codes and regulations.
 Manufacturer. The manufacturer provides information and advice regarding the product and its
application. Determine what technical services the manufacturer provides and whether these services are
available locally. Determine whether shop drawings are provided and whether orders are delivered on time
and supervised during installation. Consider how the manufacturer will handle failures and problems
involving its products.
 Installation. Determine whether the manufacturer’s directions for installation cover the particular
conditions of the project and whether there are alternate methods that must be designated in the
specifications. Consider availability of skilled workers and complexity of installation. Determine what the
preparatory and finishing requirements are for the product.
 Cost. Consider maintenance and operational costs. Initial cost should not be the only factor in selecting a
product.
2.4.2.4.Considerations during Development of Specifications
In addition to the technical and aesthetic aspects of products and materials along with their installation,
performance, and longevity, the A/E should also keep in mind factors that may affect the cost and schedule
of a project.
A. Economic Implications of Each Choice
To a large degree, it is left to the A/E to set the requirements for and, therefore, the cost of many items in the
project. The A/E should be aware of the economic impact of the requirements stated in the specifications.
B. Industry Conditions and Availability of Products
If the A/E is aware of items that may be susceptible to major availability or price fluctuations, these factors
should be considered when making product selections. Another consideration is the availability of skilled
workers within specific geographic areas.

2.4.3. Specification Method and Language
A method of specifying needs to be determined that is suitable for the products and project requirements.
 Consider the owner's requirements and policies, which may preclude use of one of the methods, such as
the proprietary or “closed” proprietary method. Note: Usually a combination of methods is used.
 Determine the type of specifications language to use: indicative, imperative, or streamlined. Note: Often
a combination of language types is used.
2.4.3.1.Specifications Language
In order to communicate with proper language, the specifier must sufficiently master the tools of
specifications language, including grammar, vocabulary, spelling, use of abbreviations and symbols,
punctuation, capitalization, sentence structure, and the unique considerations of “streamlined” writing and
specifications detail.
Precise specifications can be enforced. Vague specifications are difficult to enforce and cost the Owner
additional money because the Contractor will claim additional time and money must be added to the Contract
if a different interpretation of the specifications is enforced.
Specifications should state requirements in clear, concise, and correct terms in plain English. There are four
important Cs in specifications writing:
1. Be Clear: Avoid ambiguity. Consider the reading ability of the reader. Choose precise words that convey
exact meanings.
2. Be Correct: Present ideas and explanations accurately and precisely. Specifications should be correct
technically and grammatically. Proper terminology is important.
3. Be Complete: Do not leave out anything that is important. Brevity at the expense of completeness should
be avoided.
4. Be Concise: Eliminate unnecessary words but not at the expense of clarity, correctness, or completeness.
Typically, delete the articles “a,” “an,” and “the” where clarity is not diminished. Eliminate verbiage. A
well-crafted specification is one containing the fewest words that can be used to complete the description
and make sense.
2.4.3.2.Clarity
Specifications describe the character of the work, the desired results, and the materials and procedures needed
to complete, inspect, measure, and pay for the work. It is essential that the contract provide a very exact
definition of what the owner desires. Clear and exact language will reduce disputes and ease interpretation
and inspection.

Clarity is enhanced by:
 Arranging the text in logical order
 Discussing each detail fully and individually
 Using good sentence structure; preferably short sentences
 Being brief; a specification is not intended to be an essay, so only essential characteristics should be
described
 Using correct grammar
 Eliminating ambiguous and arbitrary statements
 Preparing fair requirements; limiting the severity of the requirements
 Eliminating uncertainty caused by terms like "as the engineer shall direct"
Analyze the completed specification from the viewpoint of the contractor and the inspector. Is it readable?
Can it be understood? Are there any hidden problems?
2.4.3.3.Consistency
Use the same writing style throughout the specifications. Use words and terms that are plain and easily
understood. Simple sentence structure is desirable.
The specifier should attempt to use an active voice or imperative mood in writing specifications; e.g. finish
the concrete, paint the surface, test the material; it should be understood that the conditions of the contract
normally specify that the contractor shall furnish, install and test everything unless specifically excluded.
Be consistent with terminology and dimensional data used on the drawings. Adequate coordination between
the bid documents, general conditions, and technical specifications and drawings will produce consistency.
2.4.3.4.Proper Use of Terms
Words or terms improperly used can cause confusion and problems. The language should be clear and exact.
Be careful with the use of certain words. Be sure the exact meaning in the specification is easily understood.
Coordinate specification terminology with the contract definitions contained in the conditions of the contract.
Several examples are given in the following articles.
A. Shall and Will. Do not interchange since it is usually understood that "shall" refers to the contractor and
"will" to the owner or engineer. Part of the problem may be eliminated by using imperative sentences
where "contractor shall" is understood, e.g. "Finish concrete with a steel trowel." Again, this should be
defined in the contract conditions.
Must and is to are not recommended.
B. Amount and Quantity Amount should be used when writing about money. Quantity should be used
when writing about number, linear measure, area, or volume.

C. Any and All.
The word "any" refers to a selective action, while "all" means everything. Usually there is no need to use
"any" or "all" since they should be understood by the context, e.g. "Steel shall be erected within the
tolerances specified."
Any is imprecise in number, permitting discretion by the reader. “Repair any cracks” could mean some
cracks selected by the contractor, but “repair cracks” means all cracks.
D. And, Or, And/Or
And connects elements that are to be taken jointly. It may also mean “plus” or “added to the preceding
quantity.” Or is used to introduce any of the possibilities in a series. The two words together, and/or,
represent a hybrid term often used in legal and business documents as a grammatical shortcut. The term
and/or is not recommended for specifications, because it allows the contractor to decide whether the term
means and or or.
E. Either and Both
Either implies a choice between two options, whereas both is all inclusive
F. Furnish, Install, and Provide:
Furnish means to supply and deliver to the project site, ready for installation. Install means to place in
position for service or use. Provide is commonly accepted in specifications to mean furnish and install,
complete and ready for intended use. These definitions should be placed in Supplementary Conditions
G. Insure, Assure, and Ensure:
To insure is to issue or procure an insurance policy. Assure is to give confidence to or convince a person
of something. Ensure is to make certain in a way that eliminates the possibility of error.
H. "Inspection" versus "Supervision."
The Engineer "inspects" the Work to ensure that it conforms to and is in accordance with the requirements
of the Contract. He/she does not "observe" it; he/she "inspects" it. The Contractor "supervises,” because
he controls and directs the various construction operations.
I. "Conformance to" versus "In Accordance with."
Materials "conform to," and workmanship is "in accordance with," the Contract requirements.
J. "Consists of' versus "Includes."
One term restricts and the other does not. "Consists of”' is used where a fixed quantity or a specific list
of items is required. The Contractor cannot be required to submit more than is listed.
When minimum requirements are specified or major items are listed, and it is clear that additional items
or requirements may be necessary, then "includes" is used.

2.4.3.5.Inappropriate Terms
Avoid using phrases that have missing objects:
 As allowed
 As appropriate
 As approved
 As directed
 As indicated
 As necessary
 As required
Avoid these adverbs:
 Hereinafter  Hereinbefore  Herewith  Wherein
Avoid these articles:
 Any  All  Such
Avoid these words and expressions:
 Etc.
 As per
 In a workmanlike manner
 To the satisfaction of the architect/engineer
 Shall function as intended
 Also
The use of the word all is usually unnecessary. Avoid using contractor as the subject of the sentence.
Poor Store all millwork under shelter. Poor Contractor shall lay brick in common bond.
Better Store millwork under shelter. Better Brick shall be laid in common bond.
Preferred Lay brick in common bond.
Pronoun Reference
The use of pronouns in specifications should be minimized or avoided. Personal pronouns should not be
used. Which and other relative pronouns should be used sparingly, if at all.
Poor Contractor shall install bathroom accessories which are to be purchased under an allowance.
Better Contractor shall install bathroom accessories to be purchased under an allowance.
Preferred Install bathroom accessories purchased under allowances specified in Section 01 21 00.
The word same should not be used as a pronoun.
Poor If materials are rejected, the contractor shall replace same at no additional cost.
Better Contractor shall replace rejected materials.
Preferred Replace rejected materials.
2.4.3.6.Abbreviations and Symbols
Abbreviations and symbols are commonplace; however, do not assume that everyone understands them. If
there is any doubt, provide definitions. It is better to eliminate abbreviations for short words (i.e., inch, foot,
high, and acre).
2.4.3.7.Spelling
Spelling should be correct and consistent, based on a particular dictionary designated as the office standard
for spelling. A supplemental list of technical terms may be needed for words not contained in the dictionary
selected as the standard. In cases where two spellings are considered equally correct, the shorter of the two
spellings is preferred for use in contract documents (e.g., facia not fascia, gage not gauge, molding not

moulding, and catalog not catalogue). However, unacceptable spellings produced by attempts at brevity or
simplification should be avoided (e.g., thru instead of through).
2.4.3.8.Sentence Structure
Two basic grammatical sentence moods can be used to clearly convey specification requirements:
• Imperative mood • Indicative mood
A. Imperative Mood
The imperative mood is the recommended method for instructions covering the installation of products and
equipment. The verb that clearly defines the action becomes the first word in the sentence. The imperative
sentence is concise and readily understandable:
 Install equipment plumb and level.
 Apply two coats of paint to each exposed surface
B. Indicative Mood
The indicative mood, passive voice requires the use of shall in nearly every statement. This sentence structure
can cause unnecessary wordiness and monotony:
 Equipment shall be installed plumb and level.
 Two coats of paint shall be applied to each exposed surface.
2.4.3.9.Numbers
The use of Arabic numerals rather than words for numbers is recommended in accordance with the following
rules:
 Use numerals whenever possible because they are easy to identify. However, when numbers are used to
define both size and quantity, the written word should be used for the quantity (e.g., three 1/2-inch holes).
 Always use figures for dimensions, degrees of temperature, percentages, and dollars and cents (e.g., 3
inches by 5 inches, 10 degrees C (50 degrees F), 20 percent, $5.50).
2.4.3.10. Capitalization
Capitalization should be consistent throughout the contract documents. Capitalization of the initial letter of
certain specific nouns and of proper names defined in the conditions of the contract is appropriate.

Example on Specification writing
Item
No.
Description original Description Corrected
1.01 Site clearing and removing the top
soil to a depth not exceeding 200
mm
Clear and remove top soil, vegetation and bushes with a
diameter of less than 80 mm as per the drawing, BaTCoDA
and as per instruction of the Engineer including 1 m working
space on either side of the building.
1.02 Bulk excavation in ordinary soil
to a depth of up to 1500 mm from
reduced level.
Excavate in ordinary soil to a depth not exceeding 1500 mm
starting from reduced level as per drawing, standard
specification BaTCoDA and instruction of the engineer.
1.03 Excavation for footing to a depth
not exceeding 1500 mm in
ordinary soil.
Ditto as item 1.02, but for footing including 250 mm working
space on either side of footing pad.
2.00 Concrete Work
2.01 Providing and laying controlled
cement concrete C25 and curing
complete excluding cost of
formwork and excluding the cost
of reinforcement for reinforced
concrete work in:
Provide, cast and vibrate in a formwork reinforced cement
concrete grade C25 with minimum cement content 360 kg per
cubic meter, and cure complete as per drawing, BaTCoDA,
and instruction of the engineer. The unit price do not include
cost of formwork and reinforcement.
a. For footing pad a. For footing pad
3.00 Masonry Work
3.01 50 cm thick basaltic stone
masonry bedded in cement mortar
of ratio 1:4.
Provide and build 50 cm thick basaltic or equivalent roughly
dressed stone masonry wall in cement mortar of ratio 1:4 as
per drawing, BaTCoDA, and instruction of the engineer. Price
include cost of cement mortar, scaffolding etc.
4.00 Sanitary Installation
4.01 Supply and install galvanized
steel water pipe for water
distribution to all sanitary
fixtures. Complete with the
necessary fittings like bends, tees
and all incidental works thereto.
Supply, install and test galvanized steel water pipe for water
distribution to all sanitary fixtures with Complete fittings like
bends, tees and all incidental works thereto as per the drawing,
BaTCoDA and instruction of the engineer. The unit price
include all necessary assistance to the installation works such
as chiseling of walls, beams, slabs, and floors; fixing pipes
with metal straps to the surfaces and sealing with concrete or
cement mortar to normal conditions.

3. TAKING OFF QUANTITIES
3.1. Introduction
The need for measurement
Measurement is vital for construction project at various stages from the feasibility stage through to the final
account. In order to establish a budget price, give a pre-tender estimate, provide a contract tender sum or
evaluate the amount to be paid to a contractor.
Taking Off Quantities
The quantification process involves recording dimensions and is referred to as taking off because it involves
reading or scaling (taking off) dimensions from a drawing and entering this information in a standard manner
on purpose ruled paper called dimension paper or take off paper. The quantity “take-off” is an important part of
the cost estimate. It must be as accurate as possible, and should be based on all available engineering and design
data, and use of appropriate automation tools as available. Quantity takeoff process is mainly calculation of
volumes, areas and counting of elements, but it requires an organized approach to every drawing and
construction item to ensure that not a single work item is missed.
Quantity surveying
Quantity surveying is a term or processes used in the construction industry to take measurements of civil
works, prepare specifications, and estimate the cost of works either for each trade of work or for the whole
project. It is the application of standard methods of measurement to quantify the amount of various items
work by taking dimensions from the drawing from construction project start up to its final completion, in
order to undertake valuation, and certify payments.
The expert [person] who is engaged in estimating quantities and their corresponding cost is known as quantity
surveyor and he must have good practical knowledge about construction materials, drawing readings,
computation of cost, and construction codes.
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. Valuation of property

Purpose of Quantity Surveying
The purpose of quantity surveying hence the preparation of Bill of quantities is:
A. Owner perspective:
 Initial (preliminary) estimate of the project costs at the different stages of the project.
 Assist the client to have an accurate estimate of the volume of work as well as the required budget.
 Preparing the BOQ as a requirement of the contract documents.
 To assist in the accurate preparation of tenders, by providing uniform measurement of quantities.
 Estimating the work done for issuing the contractor payments.
 To give an accurate checklist of work accomplished
 To assist in the certification of payments
 To give insight into the required variation work amounts.
B. Contractor perspective:
 Pricing different work items.
 Identifying the needed resources (Labor, Equipment, etc.).
 Project schedule.
 Preparing invoices for work done.
 Subcontractors’ payments.
 Review and control of crews’ production rates.
3.2. Units of measurement
Depending on the prevailing system of measurement in any locality, quantities may be measured in the FPS
system (foot, pound and second) or the metric system (meter, kilogram and second). In Ethiopia, the most
common unit of measurement is the International System of Units, or the metric system of units in which the
various items are measured as follows:
 For the measurement of length Meter (m)
 For the measurement of mass Kilogram (Kg)
The units of measurements are mainly categorized for their nature, shape and size and for making payments
to the contractor. The principle of units of measurements normally consists the following:
a) Single units work like piles, doors, windows, precast concrete, trusses etc., are expressed in numbers (no.).
b) Works consists linear measurements involve length like windows sills, pipes, skirts, stair steps, cornice,
fencing, hand rail, bands of specified width etc. are expressed in linear meter (lm) or running meters (RM)
c) Works consists areal surface measurements involve area like plastering, white washing, partitions of
specified thickness etc. are expressed in square meters (m2
).
d) Works consists cubical contents which involve volume like earth work, cement concrete, Masonry etc. are
expressed in Cubic meters (m3
).

Table below shows units of measurement of various items of civil engineering works based on BATCODA
technical specification.
S.
No.
Particulars of item Unit of
measurement
Unit of payment
1 Earthwork and Excavation work
Site clearing
- Removal of bushes & vegetation including
trees up to 80mm in diameter.
m2
m2
- Removal of termite hills m3
m3
- Removal of structures lump sum, m2
or m3
lump sum, m2
or m3
- Excavation: Bulk excavation, Pit excavation
and Continuous trench excavation.
m3
m3
- Fill m3
m3
- Disposal m3
m3
Sundry Items
- Termite proof solution (area of application) m2
m2
- Gravel sub-base m2
m2
- Hard core & stone filler
- Hard core & stone filler (depth >30 cm)
m2
m3
m2
m3
- Dust blinding m2
m2
- Trimming of slopes m M
2 CONCRETE WORK
- Cast in place concrete m3
m3
- Ribbed slabs by stating thickness, lean
concrete
m2
m2
- Grouting and filling to holes by stating sizes enumerated enumerated
- Formwork m2
m2
- Steel Reinforcement bars Kg or Quintal Kg or Quintal
- Precast units (stating sizes) m or enumerated m or enumerated
- Concrete ancillaries (stating sizes) m or enumerated m or enumerated
3 MASONRY WORK
- Stone wall m3
m3
- Stone paving by specifying thickness, Stone
work in a wall facing
m2
m2
- Brick & block wall by specifying thickness m2
m2
- Roofing & water proofing m2
m2
- Decorative (reflective) coat to roofing m2
m2
- Roof cover, side cladding, water proofing m2
m2
- Ridges, flashing, aprons down pipes, gutters,
down pipe by stating girth
m M

4 CARPENTRY & JOINERY
- Structural timber other than truss m m
- Roof trusses enumerated enumerated
- Boarding, flooring, partitions, Soffits, curtain
walls
m2
m2
- Doors and opening windows on panel
partitions
enumerated enumerated
- Fascias, eaves, barge boards, skirting by
stating girth
m m
- Doors and windows, doors and windows
fittings (like hinges, tower bolts, sliding bolts,
handles)
- Built in furniture and boards enumerated or m enumerated or m
- Shutters of doors and windows (thickness
specified)
m2
m2
5 STRUCTURAL STEEL WORK
- Stanchions, beams, trusses, purlins, ceiling
support, bracing, rails, Connection plates, base
plates, angles ties, brackets
kg Kg
- Hold down bolts including bolts, anchors and
spacers stating sizes
enumerated Enumerated
6 METAL WORK
- Floor plates, duct covers, suspension profiles,
ladders metal corner protection and linings by
stating sizes
m m
- Stairway and balustrade rails by stating girth m m
- Protective grills fixed to windows and doors m2
m2
- Doors and windows by stating sizes enumerated enumerated
- Curtain walls m2
m2
- Louver frames by stating number of blades enumerated in pairs enumerated in pairs
7 PLASTER, PAINTING & POINTING
- All finishes to floors, walls except skirting,
copping and cills
- Plaster to ribbed or corrugated surfaces
- Risers, treads and landing to stairs.
- Painting, wall papers, plastic and fabric
m2
m2
- Skirting, Cills and copings, dividing strips in
floors (expansion joints filled with sand &
bitumen) measured by specifying materials
size and thickness
m m

- Special application to edge by stating the girth
of the surface exposed for painting
- Paints to metal surface area or the weight of
the metal to be used
area or the weight of
the metal to be used
- Glass panes of special shape and decoration enumerated enumerated
- Mirror measured by stating size enumerated enumerated
8 SANITARY AND ELECTRICAL
INSTALLATION
- Pipes taken along the centerline and over all
fittings
- Insulation to supply lines by specifying pipe
diameter and along the centerline of the pipe
- Duct Work by stating the girth
- Wire fencing by stating height
m m
- Valves
- Fixtures including all accessories valves,
connection, control devices and supports for
the satisfactory operation of the fixture
- Connections to supply main
- Catch pits and manholes by stating the size
- Fence post by specifying post type height and
size
- Asphalt paving m2
m2
Damp proof course (DPC) –thickness mentioned m2
m2
3.3. Rules for measurement
In order to standardize measurement rules and conventions, there are a number of standard codes and methods
of measurement that are available. These are outlined below.
1. Measurement shall be made for finished item of work and description of each item shall include materials,
transport, labor, fabrication tools and plant and all types of overheads for finished the work in required
shape, size and specification.
2. Each item shall be fully described and shall include wherever necessary all materials, transport, unloading,
stacking, storing waste, handling, return of packing, necessary scaffolding, safety appliances, lighting at
place of work, all labor required for finishing to its shape, size, setting, fitting, and fixing in position,
cutting, waste and all other incidental operations where necessary.
3. In booking dimensions, the order shall be in the sequence of length, breadth or width, and height or depth
or thickness.
4. Same type of work under different conditions and nature shall be measured separately under separate
items stating the condition, the height or depth or distance whichever is applicable.

5. The bill of quantities shall fully describe the materials, proportions, workmanships and accurately
represent the work to be executed.
6. In case of masonry (stone or brick) or structural concrete, the categories shall be measured separately and
the heights shall be described as:
 From foundation to plinth level
 From plinth to first floor level
 From first floor to second floor level and so on.
 Unless otherwise stated all works shall be measured net as fixed in position;
Dimensions shall be measured to the nearest 0.01m,
Areas shall be worked out to the nearest 0.01m2
,
Cubic contents shall be calculated to the nearest 0.01m3
,and
Weight shall be worked out to the nearest 0.001tonne.
 Work to be measured separately [where applicable];
Work in or under water, Work in liquid mud, Work in under foul position, Work under tides, or
Work in snow.
 No deduction shall be made for voids up to 0.25m2
in area.
 No deduction shall be made on curtain walls & panel partition for openings.
 Plasterwork, finishing works and finishing on corrugated works shall be measured flat without addition
for edges and returns.
 Curved, spherical and conical surfaces shall be measured along the surface.
 No deduction shall be made to voids in glazing.
 The area of formwork to be measured is the net area in contact with the finished face of concrete with no
allowance made for passing at angles, overlaps and intersections.
 Use standard formats like 'take off sheet' or 'dimension paper' and 'bending schedule'.
3.4. METHODS OF TAKING OUT QUANTITIES
Mensuration is the term used by mathematicians to describe the measurement of lengths, areas and volumes
of different figures. It is necessary to understand the principles of mensuration before dimensions can be
correctly presented and recorded on dimension paper.
Girths
One of the most frequently used techniques when booking dimensions is ‘girthing’. Most buildings are based
on a square or rectangular plan shape and it is often necessary to establish the perimeter of individual rooms
or whole buildings either internally or externally. Whilst the drawings will show plan dimensions, before these

can be set down and recorded on dimension paper it will be necessary to build up perimeter lengths as waste
calculations. This length is required for foundations, walls and associated items.
1. Measurement of Areas
A. Measurement of regular areas may be carried out by using the standard formulae. Measurement of
areas and volumes
B. Irregular areas may be measured by one of the following methods, and then checked independently
using one of the two other methods:
1) By planimeter; or
2) By dividing the area into a number of regular areas. The smaller the regular areas adjacent to the
irregular outline, the greater the degree of accuracy; or
3) By Simpson's Rule or Trapezoidal Rule. The smaller the interval between sections, the greater the
degree of accuracy.
2. Measurement of Volumes
A. Measurement of regular volumes may be carried out by using the standard formulae.
B. Irregular volumes may be measured by one of the following methods, and then checked independently
by using one of the four other methods :
1) By dividing the volume into a number of regular volumes,
2) By End-areas method,
3) By Simpson's Rule to obtain the areas of contours,
4) By Simpson's Rule to obtain the areas of equally spaced cross-sections, and
5) By planimeter, (c) or (d), for contours or cross-sections.
When measurements of volumes require the use of contours or cross-sections, the spacing should be taken
in accordance with the following table:

Source: (Project Administration Handbook for Civil Engineering Works, 2010)

Irregular areas may be measured by one of the following methods, and then checked independently using
one of the two other methods:
(a) By planimeter; or
Source: (Project Administration Handbook for Civil Engineering Works, 2010)

The quantities like earth work, foundation concrete, brickwork in plinth and super structure etc., can be
workout by any of following two methods:
a) Long wall - short wall method
b) Centre line method.
c) Partly center line and short wall method.
a) Long wall-short wall method:
In this method, the wall along the length of room is considered to be long wall while the wall perpendicular
to long wall is said to be short wall. To get the length of long wall or short wall, calculate first the Centre line
lengths of individual walls. Then the length of long wall (out to out) may be calculated after adding half
breadth at each end to its Centre line length. Thus the length of short wall measured into in and may be found
by deducting half breadth from its Centre line length at each end. The length of long wall usually decreases
from earth work to brick work in super structure while the short wall increases. These lengths are multiplied
by breadth and depth to get quantities.
 Long Wall (Out – to - Out) = Inner Length + 2 Times Thickness of the Wall
 Short Wall (In – to – In) = Outer Length - 2 Times Thickness of the Wall
b) Centre line method:
This method is suitable for walls of similar cross sections. Here the total center line length is multiplied by
breadth and depth of respective item to get the total quantity at a time. When cross walls or partitions or
verandah walls join with main all, the center line length gets reduced by half of breadth for each junction.
Such junction or joints are studied carefully while calculating total center line length. The estimates prepared
by this method are most accurate and quick.
c) Partly center line and partly cross wall method:
This method is adopted when external (i.e., all-round the building) wall is of one thickness and the internal
walls having different thicknesses. In such cases, center line method is applied to external walls and long wall-
short wall method is used to internal walls. This method suits for different thicknesses walls and different
level of foundations. Because of this reason, all Engineering departments are practicing this method.

Figure 3.4: Plan of a room layout
Example1: Determine the internal, external and centerline girths for the room plan shown below.
External girth Internal girth Centerline girth
Example 2: - Determine the different girths for the buildings layout shown below.
(a)
(b)
Solution to example 2 (a) Solution to example 2 (b)

TAKE OFF SHEET PREPARATION
The standard forms used for entering the dimensions taken or scaled from the drawings to determine the
accurate quantity to each trade is called ‘’take off sheet’’ or ‘’dimension paper’’. The form is shown below
1 2 3 4 1 2 3 4
Columns-1(15mm): is called ‘timesing column’ in which multiplying figures are entered when there is more
than one particular items being measured.
Column-2 (16mm): is known as ‘dimension column’ in which the actual dimensions, as scaled or taken direct
from the drawing are entered. Theses may be one, two or three items dimensions in an
item depending on whether it is linear, square, or cubic. The order of dimensions in such
cases is to be length, width, and depth.
Column-3 (16mm): - is named ‘Squaring column’ in which the length, area, or volume obtained by
multiplying the figure in column-1 and -2 is recorded readily for transfer to the bill.
Column-4 (64mm): -is called ‘description column’ in which the writer descriptions of each item is entered.
 The right hand side of this wider column is used to do as above. But sometimes it is used to accommodate
preliminary calculations, data and other basic information needed in building up the dimension and
reference to the locations of the work and is referred as ’waste’.
Tip:Before actually measuring any work we must become familiar with the types of dimensions, the ways in
which they are written on the dimension papers and also other terms used in taking off process such as:
Types of dimensions as linear, square, cubic or enumerated
The descriptions,
Bracketing,
Timesing,
Dotting on,
The ampersand,
Corrections of dimensions, and
Waste calculations
Entering Dimensions
 A constant order of entering dimensions must be maintained throughout, that is (1) length, (2) breadth or
width, and (3) depth or height, so that there can be no doubt as to the shape of the item being measured. If
this is not possible, dimensions should be annotated to indicate length, width or breadth, height or depth,
diameter, etc.

 Dimensions should usually be recorded in meters to three decimal places and a line drawn across the
dimension column under each set of measurements.
 Ample space should be left between all items on the dimension sheets so that it is possible to follow the
dimensions with ease and to enable any items, which may have been omitted when the dimensions were
first taken off, to be inserted subsequently.
 Each dimension sheet should be headed with the contract number, and the abbreviated contract title, section
of the job and the drawing number(s) to which the taking-off sheet referred at the head of each sheet. Each
sheet should be numbered consecutively at the bottom.
Alterations to Dimensions
 All entries in the dimension sheet should be made in ink or blue/black ball pen. Erasable ball pens should
not be used. If it becomes necessary to amend any dimensions that have been entered on the dimension
paper, this should never be done by the use of correction fluid or eraser, or by altering the actual figures.
 The correct procedure is to write NIL in the squaring column beside the incorrect dimensions and re write
the new dimensions immediately above or below depending on the space available.
Waste Calculations
Ideally dimensions can be read directly from the drawings and entered directly into the dimension column.
However, direct transfers are not always possible as some calculation or adjustment may be required to the
dimensions on the drawing before they can be correctly booked.
The right hand side of the description column is commonly referred to as the waste. The waste is used to build
up dimensions and to carry out other preliminary calculations. Quantity surveyors call these ‘waste
calculations’ or ‘side-casts’ and they are worked out in millimeters alongside the item to which they relate.
Once the dimension is calculated, it is transferred into the dimension column in meters to two decimal places.
A key principle of taking off is the elimination of mental arithmetic. All steps that have been taken in arriving
at a dimension should be included in the waste calculation. This enables the dimensions to be checked and will
reduce doubts and misunderstandings. There may be a temptation to scribble these or carry out simple
arithmetic in the head. Both should be avoided as it is important to be able to identify the process by which the
dimensions were established. Double underlining in a waste calculation usually indicates that the result has
been transferred to the dimension column.
Deductions
After measuring an items, it is sometimes necessary to deduct for voids and/or openings. After measuring an
items, it is sometimes necessary to deduct for voids and/or openings. The letters “Ddt” in the squaring column
stand for the word ‘deduct’. The net total of the blockwork has been labelled TOT A as it will be reused during
the later stages of the take off.

One of the key techniques used by surveyors in measuring work ‘the golden rule of measurement’ is to measure
in full in the first instance and subsequently adjust for the detail; this process frequently involves deduction.
ILLUSTRATION
 The descriptions are phrased from the standard methods of measurements of building work.
 In these examples the right hand half of the dimensions’ paper is detailed in order that these explanations
may be given.

Bending schedules
Usually for reinforced concrete structures, the amounts of the reinforcements used is measured separately. The
format for taking off is shown below.
Project Name:___________________
Location:__________________
Employer:_______________ Block.:________________
Contractor:________________
Sub/ Super St r uct ur e
No. of bar
Elem.T.No ø6mm ø8mm ø10mm
ø12mmø14mmø16mm ø20mm
ElevationColumn-A
At level +.00-+3.40
Left side
C-1 20 4.20 8 2 16 - - - - - - 67.20
St 8 1.10 18 2 36 - 39.6 - - - - -
- 39.6 - - - - 67.20
0.222 0.395 0.617 0.888 1.209 1.579 2.467
- 15.64 - - - - 165.78
____________________________ _____________________________
Sub total
Location Shape
Dia
(mm)
Length
(m)
No of bars
Totallength(m)
Unit weight
Totalwt (k.g)
Contractor Consultant
To find the weight of the reinforcements for the known length of bar, the following formula can be used to
compute the weights per unit length of bars of diameter d.
36
*
222
.
0 2
d
Wt
Where d = diameter of bars in mm
Wt = weight of bar per unit length
3.5. Taking out quantities
It is vitally important that measurement practice applied to buildings is both accurate and consistent. There are a
number of situations that require a quantity surveyor to measure and record dimensions from both drawings as
well as on site, depending on the stage of the project. This section covers example on preparation of a quantity
take-off for G+1 building.

1. Earth works
Earth works comprises site clearing, excavation, backfilling and transportation of excavated materials.
1.1.Site leveling:
-Site leveling/clearing is removal of bushes & vegetation, removal of termite hills, and removal of structures
(the Ethiopian Building and Transport Construction Design Authority, BaTCoDA).
-Site leveling/clearing is measured in m2
(area) if thickness less than 30 cm and it is measured in m3
(volume)
if thickness more than 30 cm. Site clearance shall be understood as including trees up to 80mm in diameter.

1
1
17.87
9.10
17.87
9.10
0.50
162.62
81.31
A. SUB STRUCTURE
1. Excavation and earthwork
1.1.Site clearing
The dimension for site clearing will be determined by adding working space on
either side of building or bulk excavation size by including 25 cm to either side of
the building. In this example consider 1m to either side of the building. Thus,
 The length= building dimension plus twice working space =15.87+2*1=17.87 m
 The width= building dimension plus twice working space =7.10+2*1=9.10 m
m 2
Total area of site clearance
N.B: Excavation: Bulk, pit and trench excavation
- Prices differ based on the soil type, deep of excavation, ground water level, site
location, shoring system, Equipment used, etc.
- Unit of measurement is cubic meter (volume).
1.2.Bulk excavation
The limits of bulk excavation for the measurement shall be as shown on drawings.
If not shown, the limits shall be, the surface area covered by the permanent structure
resting on the area of bulk excavation plus the working space allowed for trench or
pit excavations for the foundations of the permanent structure. The working space
shall be determined by the Engineer but shall not exceed 500mm on either side of
the limits of the area to be excavated (BaTCoDA).
In this example consider 1m to either side of the building. Thus,
 The length=building dimension plus twice working space =15.87+2*1=17.87 m
 The width= building dimension plus twice working space =7.10+2*1=9.10 m
m 3
Total volume of bulk excavation

10 2.30
2.30
1.45
76.71
1.3. Pit excavation for isolated footing in ordinary soil to a depth not exceeding 150cm
from reduced ground level.
Pit and trench excavation shall be measured by adding
250mm to each side of the dimension giving the surface
area of the volume to be excavated. Excavation shall be
measured in successive stages of 1500mm from starting
level.
The depth of pit excavation =Reduced level of footing
minus reduced level of ground level =3-0.9=2.1 m. But, during site clearing and
bulk excavation the reduced level is reduced by 0.7 m. Thus, the depth to be
excavated is 1.4 m (2.1m -0.7m). Total depth including 5 cm lean concrete is 1.45m.
In this example, there are 10 footings pads with size 1.8 m by 1.8 m. The excavation
size become 2.30m (1.8m + 2*0.25m working space).
m3
Total volume of pit excavation

2
4
3
2
1.58
0.98
0.3
2.05
1.00
0.30
2.30
0.98
0.30
2.02
1.00
0.30
3.10
2.46
2.03
1.21
1.4. Trench excavation for peripheral retaining wall foundation to a depth of not
exceeding 50cm including 25cm working allowance for each side.
The depth of trench excavation from above figure is 1.0 m (=1.9-0.9) from natural
ground level, but a depth 0.7m is already cleared while excavating site clearance
(0.2m) and bulk excavation (0.5m). Thus, trench excavation depth is 0.3m (=1-
0.7).
A) For part 1 shown foundation plan with dimension 0.98m by 1.58m
m3
B) For part 2 shown foundation plan with dimension 2.05m by 1m
m3
C) For part 3 shown foundation plan with dimension 2.30m by 0.98m
m3
D) For part 4 shown foundation plan with dimension 2.02m by 1 m
m3

2
2
2.75
1.00
0.30
1.00
0.21
0.30
1.65
0.13
10.58
E) For part 5 shown foundation plan with dimension 2.75m by 1 m
m3
F) For part 6 shown foundation plan with dimension 1 m by 0.21 m
m3
m3
Total volume of trench excavation
1
1
14.88
6.11
0.50
14.63
6.36
0.05
201.04
16.66
21.13
163.25
45.46
N.B: - Backfilling:
-Fill shall be placed in successive stages of not exceeding 200mm and watered and
compacted to approval by the Engineer.
-Fill shall be measured as equal to the net volume of void to be filled and shall be
understood as including the stockpiling and haulage of material from location of fill.
-Backfilling = Excavation – volume of all works inside the excavated pit (footings,
column necks, masonry work, etc.) + amount above GL (or – amount below GL)
-Volume of backfilling = excavation – concrete – Stone masonry below natural ground
level (NGL).
1.5.Selected granular material fill from borrow pit and well compacted in layers not
exceeding 20cm at dry density and optimum moisture content. The degree of
compaction and the material should be approved by the engineer.
a) around footing pad, footing column & foundation wall
Total volume of excavation=Volume of site clearing +bulk +pit +trench
=area of site clearance*thickness +bulk +pit +trench
m3
=162.2*0.2+81.31+76.71+10.58=201.04 m3
Total volume of concrete work=volume of lean concrete (32.40 m2
) +footing pad
+ footing column below (NGL) =32.4*0.05+12.96+10*0.35*0.35*(2.2-0.5)
m3
=1.62+12.96+2.08=16.66 m3
.
m3
Total volume of stone masonry below NGL=21.13 m3
.
m3
Total volume of Back fill
b) under hardcore (above NGL)
 Fill up to grade beam level with depth=0.9-0.4=0.5m
Length of long side fill= in to in dimension of masonry=14.88m
Length of long side fill= in to in dimension of masonry=6.11m
m3

4.65
50.11
 Fill between hardcore and bottom of grade beam level=0.4-0.35=0.05m
Length of short side= out to out dimension–grade beam intersection=7.11-
3*0.25=6.36m
Length of longer side= out to out dimension–grade beam intersection=15.88-
5*0.25=14.63m
m3
m3 Total volume of back fill under hardcore
Disposal
-All unsuitable and surplus suitable material arising from excavations shall be disposed off when instructed by
the Engineer.
-Disposal shall be made to tips directed by the Engineer or indicated in the document. In the absence of direction
from the Engineer or indication in the documents, it is the contractor’s responsibility to identify the appropriate
tip and dispose the material.
-Disposal shall be understood to include stock piling, loading, transporting, dumping and wheel spreading at
tip.
-Disposal shall be measured as the net volume arising from the void created by the excavation, less excavated
material backfills, filled and wheel spread within site or left stockpiled.
-Transported soil = vol. of exc. – vol. of backfilling + additional soil at site
-Add swelling factor based on the soil type: 5% sandy soil. 15% clayey soil and 25% for demolition material.
(owner or contractor)
113.75
1.6.Load and cart away surplus excavated material to a suitable damping area allowed
by the municipality not more than 10 km from the site.
Transported soil = vol. of exc. – vol. of backfilling + additional soil at site
=201.04-163.25=37.79 m3
, this is volume occupied by structure.
But, in this example the volume of materials to be disposed or cart away is the
volume of site clearance and bulk (i.e. 113.75 m3
(=162.2*0.2+81.31)).
In this example, the volume of excavation used as cut to fill is pit excavation and
trench excavation volume (87.29 m3
). This implies that back filling requires
additional borrow material of 75.96 m3
(=163.25-87.29) is required as borrow to
fill.
m3
Total volume of cart away

Hard core & stone filler
 Hard core shall be sound approved stone of specified finishing thickness and placed as directed by the
Engineer and finished blinded with 20mm crushed aggregate.
 Hard core shall be measured by the area of the surface on which it is laid if the finished thickness does not
exceed 300mm.
 Hard core and stone filling exceeding 300mm thickness shall be measured by the volume of void filled by the
hard core or stone chipping.
1 14.63
6.36
93.05
1.7.An average of 25cm thick basaltic or equivalent stone hardcore well rolled,
consolidated and blinded with crushed stone.
Net length for hardcore = 15.38m-3*0.25m =14.63 m
Net width for hardcore = 6.61 m-0.25 m = 6.36 m
m2
Total area of hardcore
Plain concrete (PC):
- Measured in m2 (area) if thickness < 20 cm.
- Measured in m3 (volume) if thickness ≥ 20 cm.
- Average thickness should be mentioned when measurement is done by area.
Reinforced concrete (RC):
- All RC elements measured by volume (m3
) except hollow block slabs measured by area (m2
).
- Domes, cylindrical roofs and shells measured by area in the horizontal projection.

10
1
7
3
1
10
1.80
1.80
43.98
0.50
0.35
0.35
5.76
0.25
13.83
0.25
1.8
1.8
0.4
32.40
21.99
0.86
21.13
4.32
3.46
7.78
12.96
2. Concrete Work
2.1. 5cm thick lean concrete class C-5 with a
minimum cement content of 150Kg/m3
a) under footing pad
m2
Total area of lean concrete under footing pad
b) under foundation wall
Perimeter of the lean concrete under masonry=2*short wall+2* long wall
= 2*6.11+ 2*15.88=43.98m
m2
Total area of lean concrete under foundation wall
Ddt for footing column included in foundation wall with size 0.35 m by 0.35 m.
m2
Total area to be deducted from lean concrete under interior grade beam
m2 Total area of lean concrete under foundation wall
c) under interior grade beam
(L=6.11-0.35=5.75 m)
m2
Total area of lean concrete under interior grade beam
L=(14.88-0.35*3)=13.83m
m2
Total area to be deducted from lean concrete under interior grade beam
m2 Total area of lean concrete under interior grade beam
2.2.Reinforced concrete class C-25 with a minimum cement content of 360kg/m3
filled
in to form work and vibrated around reinforcement bar (formwork and
reinforcement measured separately).
a) In isolated footings
Thickness of footing pad is 40 cm
m3
Total volume of concrete in footing

CSQS ch 1, 2& 3 lec. note.pdf

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CSQS ch 1, 2& 3 lec. note.pdf