UNIVERSITY OF NAIROBI

SCHOOL OF THE BUILT ENVIRONMENT

DEPERTMENT OF REAL ESTATE AND CONSTRUCTION MANAGMENT

A STUDY ON THE EFFECTS OF DESIGN CHANGES ON THE CONTROL OF

CONSTRUCTION PROJECTS IN KENYA; CASE STUDY OF NAIROBI

COUNTY.

SUBMITTED BY:

AHMED ALBASHIR IBRAHIM

REG NO. B66/0345/2009

A RESEARCH PROJECT SUBMITTED IN PARTIAL FULFILMENT OF THE

REQUIREMENT FOR AWARD OF BACHELOR DEGREE OF QUANTITY

SURVEYING.

MAY 2013

i

DECLARATION

STUDENT

I Ahmed Albashir Ibrahim, declare that this is my original work and has not

been presented for any award in any organization of learning or examination

body.

Signed: ------------------------------------- Date: --------------------------

AHMED ALBASHIR IBRAHIM

SUPERVISOR

This project has been subjected for examination with my approval as the

University Supervisor.

Signed: ------------------------------------- Date: --------------------------

ARCH. J. ODWALLO

DEDICATION

I wish to dedicate this project to my parents, Ahmed Ibrahim and Abdia

Mohamud, for their undying love, support and for always being there for me.

To my Uncle and Mentor, Mr. Abdilatif Osman, for his professional guidance and advice

ACKNOWLEDGEMENT

This project would not have been successful without the invaluable contribution by many

people in various ways and I wish to hereby thank them.

First and foremost, I wish to acknowledge Arch. J. Odwallo for the guidance and

contribution as well as for his support and encouragement throughout the project duration

as my supervisor. I would also like to thank all the lecturers of the department of real

estate and construction management who contributed to my project through the daily

classes, seminar held and the continuous review and comments on my project. I wish to

specifically thank Qs. Kennedy Mwendwa in this regard.

I am also grateful to the staff and administration of the Nairobi city council (NCC),

department of development control, for allowing me to collect useful information from

their institutions.

I would also like to pay special tribute to all the respondents who took time from their

busy schedules to answer my questions, this project would not have been completed

without their cooperation.

Special votes of thanks goes to my parents for their unflinching support and belief in me

even when I didn’t, and to my siblings who have always given me a reason to work hard

and succeed in all that I do.

And last but not least, I would like to acknowledge the support of my classmates and for

their continued support and encouragement throughout my 4 years in the university. In

this regard, I would wish to thank Nicodemus Chege, My classmate and roommate for his

continuous advice and support on my academic life.

MAY GOD BLESS YOU ALL!

TABLE OF CONTENTS

DECLARATION ................................................................................................................. i

DEDICATION.................................................................................................................... ii

ACKNOWLEDGEMENT ................................................................................................. iii

TABLE OF CONTENTS................................................................................................... iii

LIST OF TABLES............................................................................................................ vii

LIST OF FIGURES ......................................................................................................... viii

ABBREVIATIONS ........................................................................................................... ix

ABSTRACT........................................................................................................................ x

CHAPTER ONE ................................................................................................................. 1

INTRODUCTION OF THE STUDY ................................................................................. 1

1.0 INTRODUCTION................................................................................................ 1

1.1 BACKGROUND INFORMATION..................................................................... 1

1.1.1 Design changes ............................................................................................. 1

1.1.2 Construction project control ......................................................................... 3

1.2 STATEMENT OF THE PROBLEM ................................................................... 4

1.3 OBJECTIVES OF THE STUDY ......................................................................... 6

1.3.1 General Objective ............................................................................................... 6

1.3.2 Specific Objectives ............................................................................................. 6

1.4 HYPOTHESIS ..................................................................................................... 6

1.5 IMPORTANCE OF THE STUDY....................................................................... 6

1.6 SCOPE OF THE STUDY .................................................................................... 7

1.6.1 Physical Scope .............................................................................................. 7

1.6.2 Subject Scope................................................................................................ 8

1.7 RESEARCH METHODOLOGY......................................................................... 8

1.8 ASSUMPTIONS ................................................................................................ 10

1.9 DEFINATION OF TERMS ............................................................................... 10

CHAPTER TWO .............................................................................................................. 11

LITERATURE REVIEW ................................................................................................. 11

2.0 INTRODUCTION.............................................................................................. 11

2.1 THEORETICAL FRAMEWORK ..................................................................... 12

2.1.1 The Design process ..................................................................................... 12

2.1.2 Delivery of Construction Projects............................................................... 18

2.1.3 Design Changes .......................................................................................... 21

2.1.4 Causes of Design Changes.......................................................................... 22

2.1.5 Effects of Design Changes.......................................................................... 29

2.1.6 Control Tools used to handle Design Changes ........................................... 32

2.2 CONCLUSIONS................................................................................................ 36

CHAPTER THREE .......................................................................................................... 37

RESEARCH METHODOLOGY...................................................................................... 37

3.0 INTRODUCTION.............................................................................................. 37

3.1 RESEARCH DESIGN ....................................................................................... 37

3.2 STUDY POPULATION AND DESCRIPTION OF THE STUDY AREA....... 38

3.3 TARGET POPULATION.................................................................................. 38

3.4 SAMPLING DESIGN........................................................................................ 39

3.4.1 Sampling Method........................................................................................ 39

3.4.2 Sampling Technique ................................................................................... 40

3.4.3 Sampling Procedure .................................................................................... 40

3.5 DATA COLLECTION....................................................................................... 42

3.5.1 Method of Data Collection.......................................................................... 42

3.5.2 Instruments of Data Collection ................................................................... 42

3.5.3 Data Collection Procedure .......................................................................... 42

3.6 DATA ANALYSIS ............................................................................................ 43

3.7 DATA PRESENTATION AND ANALYSIS.................................................... 43

CHAPTER FOUR............................................................................................................. 44

RESEARCH FINDINGS.................................................................................................. 44

4.0 INTRODUCTION.............................................................................................. 44

4.1 RESPONSE RATE ............................................................................................ 44

4.2 DEMOGRAPHIC INFORMATION ................................................................. 45

4.2.1 Information on line of business/Profession................................................. 45

4.2.2 Information on Duration of service on the respective line of profession ... 47

4.2.3 Information on the position of the respondents in the organization ........... 48

4.2.4 Information on the Professional Associations attached to the respondents...... 49

4.3 INFORMATION BASED ON THE STUDY OBJECTIVES ........................... 51

4.3.1 Information on whether the Projects involved have experienced changes inthe initial design......................................................................................................... 51

4.3.2 Information on how the respondents ranked the causes of changes in theinitial design. ............................................................................................................. 52

4.3.3 Information on how the respondents ranked the effects of design changes inconstruction projects in Kenya .................................................................................. 54

4.3.4 Information on the design changes and control of construction projects inKenya ……………………………………………………………………………..56

4.3.5 Information on the level at which the effects of the design changes affectthe control of construction project............................................................................. 56

4.3.6 Information on the possible methods of improving existing controltechniques on design changes in construction projects in Kenya.............................. 57

4.4 CHALLENGES.................................................................................................. 59

CHAPTER FIVE .............................................................................................................. 61

DISCUSSION OF FINDINGS, CONCLUSIONS AND RECOMMENDATIONS........ 61

5.0 INTRODUCTION.............................................................................................. 61

5.1 SUMMARY OF THE FINDINGS..................................................................... 61

5.1.1 Objective 1: Causes of Design changes. ..................................................... 61

5.1.2 Objective 2: Effects of design changes on the control of constructionprojects ……………………………………………………………………………..62

5.1.3 Objective 3: Project control tools that can be used to mitigate any effect ofdesign changes ........................................................................................................... 63

5.2 CONCLUSIONS................................................................................................ 63

5.3 HYPOTHESIS TESTING.................................................................................. 65

5.4 RECOMMENDATIONS ................................................................................... 66

5.5 SUGGESTIONS FOR FURTHER STUDIES ................................................... 67

REFERENCES ................................................................................................................. 68

APPENDIX I: QUESTIONNAIRE .................................................................................. 71

APPENDIX II: LETTER OF INTRODUCTION............................................................. 76

APPENDIX III: LETTER FROM THE DEPARTMENT................................................ 77

LIST OF TABLES

Table 2.1 Pareto’s Classification of design defects……………………………….……23

Table 3.1 Target Population………………………………………………….………….40

Table 3.2 Sample Size………………………………………………………….……..…42

Table 4.1: Response Rate……………………………………………………….….……45

Table 4.2 Line of business/profession…………………………………………..…….47

Table 4.3 Duration of service…………………………………………………………..48

Table 4.4 Position of respondents…………………………………………………..…49

Table 4.5 Professional Association…………………………………………………....51

Table 4.6 Change in the initial stage…………………………………………………...52

Table 4.7 Causes of change in the initial stage…………………………………….….52

Table 4.8 Effects of design change…………………………………………………….55

Table 4.9 Design changes and control of construction projects……………………..57

Table 4.10 Effects of design change……………………………………………….….58

Table 4.11 Methods of improving control……………………………………………59

LIST OF FIGURES

Figure 2.1. Design-build versus design-bid-build ………………………….…………. 21

Figure 4.1 Response rate……………………………………………………...………….46

Figure 4.2 Line of business/profession…………………………………………………48

Figure 4.3 Duration of service………………………………………………..………….49

Figure 4.4 Position in the organization………………………………………………….50

Figure 4.5 Professional association………………………………………………………52

Figure 4.6 Response on the changes on the initial design……………………………….53

Figure: 4.7 Causes of the design changes………………………………………………..55

Figure 4.8: Effects of the design changes……………………………………………….56

Figure 4.9 Methods of control…………………………………………………………..60

ABBREVIATIONS

AAK - Architectural Associations of Kenya

Arch. - Registered Architects

BORAQS - Board of Registration of Architects and Quantity Surveyors

CPM - Critical Path Method

D&B - Design and Build method of project delivery.

ICPMK - Institute of Construction Projects Managers of Kenya

ICEK - Institute of Consulting Engineers of Kenya

IQSK - Institute of Quantity Surveyors of Kenya

JBC - Joint Building Council

KFMB - Kenya Federation of Master Builders

NCC - Nairobi City Council

PERT - Program Evaluation and Review Technique

PM - Project Managers

PMC - Project Management Consulting firms

QS - Registered Quantity Surveyors

WBS - Work Breakdown Structure

ABSTRACT

In building projects, Client requirements, Constructive aspects and Quality standards are

defined during the design phase. However, this critical phase is usually carried out with

little interaction between the construction and design teams. This has resulted in changes

to the initial design causing many problems during construction such us: incomplete

designs, change orders, rework, construction delays, etc. However, few empirical studies

have measured this Impact in the Kenyan construction industry.

This research discusses the effects of design changes on the control of construction

projects in Kenya, a case study projects in Nairobi County. The focus is on the causes of

design changes, the effects of design changes on the control of construction projects and

the control procedures adopted to mitigate these effects.

This study comprise: Extensive review of literature of the subject of design changes in,

data collection from several projects in Nairobi County, analysis of the findings,

conclusion and recommendations from the findings.

A review of the most frequent causes, effects on control and control methods used in

construction projects allowed the researcher to collect data using Questionnaires from

488 projects approved by NCC (department of development control) for development in

Nairobi County from January 2011 to December 2012.

After analysis of the data, the study found out that design changes have several effects on

construction projects. Their causes and ways used to mitigate the effects are also

discussed.

Recommendations have been given at the end of the study on the various ways design

changes can be handled in the construction industry in Kenya.

CHAPTER ONE

INTRODUCTION OF THE STUDY

1.0 INTRODUCTION

This chapter provides a background to the study, statement of the problem, objectives of

the study, research questions, significance and scope of the study.

1.1 BACKGROUND INFORMATION

1.1.1 Design changes

Construction project is usually processes with a set of inter- related activities happening

with the aim of ensuring the client’s requirements are met. These activities are usually

classified in a set of stages and phases; one very critical and important phase is the design

stage. It is in the design stage where the requirements of the client are identified and the

constructive aspects and the standards of quality are defined through procedures,

drawings and technical specifications. Currently, the work within the design stage is split

into several temporary sequences, and it is delivered to different specialists for its

execution. In building projects, first the owner selects the architects who prepare the

architectural designs and specifications, and then the structural design and other specialty

designs are developed. The structural and specialist design are then given back to the

architect who will develop the final working drawing after incorporating all the ideas of

the other consultants. The working drawing will then be used by the contractor at the

construction/ implementing phase. Generally, the construction stage is the responsibility

of a contractor, who is selected through a competitive process by the owner or the project

manager appointed by the client, the other project team i.e. the architect, structural

engineer and other specialist will be doing the supervisory role at this stage.

The main problems with this kind of sequence is the little or no involvement of the

contractor or the construction team at the design stage, this means that they will be

required to construct based on the working drawings which sometimes might be

unattainable. The little interaction among design team and construction team compels the

following phases of the construction project to work on incomplete designs. The

consequences are suboptimal solutions, lack of constructability and a great number

design changes and construction rework.

In construction projects, a design change refers to an alteration to design, building work,

project program or other project aspects caused by modification to pre-existing

conditions, assumptions or requirements (International journal of project management

2009).

The impacts of changes are not understood and rarely recognized, in terms of costs,

quality and schedule. One of the harmful consequences of design changes is rework or

revision of work (Josephson P et al 2002). The work hours invested by the designers

in the changes have been estimated in a 40 to 50% of the total of a project (Koskela

1992). It was shown by Ndhihokubwayo and Haupt (2011) that 63% of site instructions

culminated in additional works and he then suggested that more attention should be

devoted to the design stage such that issues of variation order can be minimized. In

addition, an investigation of the consequences of design changes on institutional building

projects showed they resulted into a substantial increment in amount of funding budgeted

for construction works (Arian and Pheng, 2005) Also, Increment in the project cost and

an extended duration of completion are the two main effects observed for change orders

(Arian and Pheng, 2005).

While changes are inevitable, if not properly analyzed and controlled, they may lead to

change in contract price (cost) or the construction schedule (time), Project specifications

(Quality) and they may also increase the possibility of contractual dispute. A critical

change may cause consecutive delays in project schedule, re-estimation of works

statement, and extra demands of equipment, materials, labour and overtime (Qi Hao et al

2008) In general, Changes present problems to all parties involved in the construction

process and hence it’s important to identify its impact on the control of the construction

project.

1.1.2 Construction project control

In the construction industry, the aim of project control is to ensure the projects finish on

time, within budget and achieving other project objectives. It is a complex task

undertaken by project managers in practice, which involves constantly measuring

progress; evaluating plans; and taking corrective actions when required (Kerzner,2003).

During the last few decades, numerous project control methods, such as Gantt Bar Chart,

Program Evaluation and Review Technique (PERT) and Critical Path Method (CPM),

have been developed (Nicholas 2001, Lester 2000). A variety of software packages have

become available to support the application of these project

control methods, for example Microsoft Project, Asta Power Project, Primavera, etc.

Despite the wide use of these methods and software packages in practice, many

construction projects still suffer time and cost overruns, a problem resulting from

poor control of the construction project.

In recent years, there have been numerous studies on the identification of influencing

factors of project time and cost overruns worldwide. Mansfield (1994) carried out a

questionnaire survey amongst 50 contractors, consultant and client organizations in

Nigeria and found out that the most important variables causing construction delays and

cost overruns are poor contract management, financing and payment of completed works,

design changes and changes in site conditions, shortage of materials, imported materials

and plant items, design changes, subcontractors and nominated suppliers. While the top

variables causing only cost overruns were revealed as price fluctuation, inaccurate

estimates, delays, additional work. Kaming (1997) identified factors influencing

construction time and cost overruns on high-rise building projects in Indonesia through a

questionnaire survey administered on 31 project managers. A total of 11 variables

(design changes, poor labour productivity, inadequate planning, material shortages,

inaccuracy of material Project control measures estimate, skilled labour shortage etc.)

were identified for time overrun, he had seven (materials cost increased by inflation,

inaccurate quantity take-off, lack of experience of project location, lack of experience of

project type etc.) for cost overrun. Kumaraswamy and Chan (1998) conducted a more

extensive study in Hong Kong using 400 questionnaires after which follow up interviews

were held. The study revealed the top ten causes of construction delays from the

contractors' point of view as delays in design information, long waiting time for

approval of drawings, poor site management and supervision, mistakes and discrepancies

in design documents, etc. In addition to questionnaire surveys, other researchers adopted

a case study approach. Al-Momani (2000) examined 130 public projects in Jordan and

concluded that the main causes of delays include changes initiated by designers, client

requirement, weather, site conditions, late deliveries, economic conditions, etc.

Most of the studies were carried out outside the Kenya and focused largely on the

effects of design changes and lack of control in construction projects. Although

construction projects worldwide share some common characteristics, there are also

some country specific conditions. Therefore, a Kenya based study will help to identify

issues most relevant to the contemporary practice in this country. Some of the

reviewed surveys had relatively small sample sizes, which may affect the reliability of

their results. All the studies focused on identifying factors that have the biggest

influence on project costs and time. They did not discuss the degrees of difficulty in

controlling these factors in practice. There seems to be an implicit assumption that the

most important factors are also those most difficult to control. This needs to be

explicitly validated. Finally, most existing research studied the identification of the

influencing factors, but did not narrow down specifically on design changes effects on

control of construction projects. These observations underlie the rationale for this study.

Its aim is to identify the causes of design changes, the effects of design changes on the

control of construction projects as a practice in Kenya and then to develop some

mitigating measures to assist project managers better control effects of design changes on

their projects.

1.2 STATEMENT OF THE PROBLEM

A design change refers to the alteration of the initial design or change of scope of the

work, resulting from an instruction either from the owner, contractor, project manager or

architect on the working drawings and design. It starts with a written order to, or a

request from the contractor, signed by the owner or the architect, and issued after

execution of the contract, authorizing a change in the work or an adjustment in the

contract specifications or the contract scope (Abdulghafoor 2000).

There are many causes of construction design changes in construction projects. It might

be a result of further development of the owner’s requirements, non-availability or slow

delivery of required materials, Market conditions may impose changes to the parameter

of the project or correction of contract document errors and omissions. A critical change

may cause consecutive delays in project schedule, re-estimation of works statement, and

extra demands of equipment, materials, labour and overtime (Qi Hao et al 2008). Other

common effect includes cost overruns, extension of time, design reworks and it may also

cause problems and disputes on the different consultants in the project team (Kaming

1997). Many other studies have concentrated their research on the causes and effects of

design changes in construction projects

While these changes are inevitable in any construction project, their frequency and

nature, in form of site instructions and other change orders can create delay, cost overruns

and may even cause project failure in some projects. Identifying the causes of design

changes is very important in order to understand and avoid potential changes in future

projects or minimize their effects.

It is with this reason that this study is conceived, it aims to establish the effects of design

changes on the control of construction projects in Kenya, with a focus of Nairobi County

as the case study. This study will assist owners, construction consultants and contractors

to plan effectively before starting a project and during the design phase to minimize and

control changes and change effects. This study will also lay the foundation for further

research on the subject.

1.3 OBJECTIVES OF THE STUDY

1.3.1 General Objective

The main objective of the study is to determine the effects of design changes on the

control of construction projects in Kenya focusing on Nairobi County as the case study.

1.3.2 Specific Objectives

The following specific objectives guided the study.

a) To determine the causes of design changes in construction projects in Kenya.

b) To assess the effects of Design changes on control of construction projects in

Kenya

c) To identify project control tools that can be used to mitigate any effect of design

changes on the control of construction projects in Kenya.

1.4 HYPOTHESIS

H0 (Null Hypothesis):- Design changes do not affect the control of construction projects

in Kenya.

H1 (Alternative Hypothesis):- Design changes affect the control of construction projects

in Kenya.

1.5 IMPORTANCE OF THE STUDY

The study is aimed at determining the effects of design changes on the control of

construction projects in Kenya. The successful completion of the research project is

deemed relevant to the following individuals and corporate body.

a) Construction consultants/professionals

The consultants at those construction sites will be able to know and understand the causes

and effects of design changes in construction projects. This will assist in formulation of

new strategies and amend the existing ones order to achieve better performance and

arriving at the project goal on time and within the set budget.

b) Contractors

The contractors with overall obligation of control of construction projects will be able to

know new strategies to handle design changes in the projects they are handling. This will

enable them develop better procedures regarding their strategies on how to control and

relate their work schedule to meet the deadline and obligations that are provided for in

the contractual agreements.

c) Academicians

Education seekers in one field of construction project management, Architects, Quantity

surveyors and other construction related courses will find this research study helpful.

This research project will be as well beneficial to the students of University of Nairobi as

it is kept in their main library to act as a point of reference

d) The Government

The government will be in a position to improve control of construction projects in the

country by addressing challenges being faced. Precisely, the government will benefit

through the ministries of Public works, Transport, Roads, Finance, Education as well as

information and communication. This is because the findings of this research can be

incorporated in the future plan, policies and strategies of the countries development.

1.6 SCOPE OF THE STUDY

1.6.1 Physical Scope

The study will confine itself within the county of Nairobi as the case study; this because

of the limited time and resources to carry out the research in a wider geographic area, the

choice of Nairobi was also influenced by the many construction professionals and

projects concentrated in Nairobi, as Oketch (2004) says, 70% of total construction output

in kenya is concentrated in Nairobi.

1.6.2 Subject Scope

The study will focus on large construction projects (Ksh.100 Million and above) in

Nairobi County, with a focus on projects approved by the Nairobi city council (NCC) in

2011 and 2012. This is because all development projects in Nairobi County must be

approved by NCC. The choice of 2011 and 2012 is based on the fact that the projects will

still be ongoing currently hence the ability of the developer, contractor and the

consultants to identify the cause, effects and control methods of the design changes on

the control of the construction project.

The project will aim at determining the effects of design changes on the control of

construction projects in Kenya focusing on Nairobi County. The study will factor; causes

and effects of design changes, best practice measures to ensure proper control of

construction projects as the main strategies. The target population of the study will be

randomly selected construction projects in the county of Nairobi, both residential,

commercial and mixed used buildings.

1.7 RESEARCH METHODOLOGY

The aim of the research was to find out the effects of design changes on the control of

construction projects in Kenya and, in particular, the study focused on identifying the

causes of design changes, its effect on control of construction projects and the different

ways used to mitigate the effects of design changes.

To achieve this, the researcher carried out an in-depth evaluation of the design process

with the intention of identifying instances in design changes can occur. This was done

through a review of the available literature on the design process, project delivery

methods, causes of design changes, effects of design changes on the control of

construction project and ways used to mitigate the effects. The primary sources of data

were books, journals, academic thesis and internet sources.

The researcher then investigated the effects of design changes on the control of

construction projects in Kenya, with Nairobi as the case study where projects approved

by the Nairobi city council for development, with project value of over Ksh.100 million

were the target population. This was done by use of structured questionnaires which were

the main data collection instruments. These questionnaires were structured in such a way

as to enable the researcher gather information on the causes of design changes, their

effect on the control of construction projects and the different ways used to mitigate the

effects.

Data was collected from a sample of 65 stakeholders of projects done in Nairobi County

between January 2011 and December 2012 as approved by NCC. This represented about

12% of all stakeholders of projects approved by the NCC with values over 100million

between January 2011 and December 2012.

The sample size was arrived at by use of a mathematical formula. Stratifies sampling was

used in the study and random numbers generated by a scientific calculator were then used

to select stakeholders in the different stratus to act as the subjects of the study. The

selection was done from a list stakeholders involved in the 488 construction projects

provided by the department of development control at the NCC.

Data analysis was done using the MS Excel office application and presented using

graphs, pie charts and frequency distribution tables.

1.8 ASSUMPTIONS

a) All projects executed in Nairobi county MUST get approvals from Nairobi City

council.

b) All projects Approved by NCC between January 2011 and December 2012 have

commenced and are in the execution stage.

1.9 DEFINATION OF TERMS

Change order: - A change order is the formal document that is used to modify the

original contractual agreement and becomes part of project’s documents (abdulhghafoor,

2000).

Consultants: - For the purpose of this study, Consultants will refer to Architectural,

Quantity surveying and Project management firms involved in the projects.

Construction project control: - The project management team action, either preplanned

to achieve the desired construction project objectives.

Constructability: - The optimum use of experience in design, procurement and planning

to achieve the objectives of the project in the least possible cost.

Control Account: - A selected account to manage resources, productivity and historical

database.

Cost Overruns: - The difference in cost between actual and original contract award

amount.

Creeping Scope: - Loss of control of a project scope. Creeping scope provides good

grounds for construction and design changes.

Design change: - For the purpose of this study, Design change refers to a modification or

alteration on the working drawings at the construction phase of the project.

Post contract stage: - The period before the signing of the construction contract between

the contractor and the client.

Pre-contract stage: - The period after the execution of the building contract.

Work Breakdown Structure (WBS): - An ordered representation of the construction

project organized in an increasing detail array.

CHAPTER TWO

LITERATURE REVIEW

2.0 INTRODUCTION

This chapter contains an extensive and thorough review of relevant publications and

studies related to the research problem under investigation in order to obtain detailed

knowledge about the area under study.

2.1 THEORETICAL FRAMEWORK

2.1.1 The Design process

Design refers to drawings and specifications that are used in any building and

construction projects to implement the client/Owner requirements. In Kenya, the aspect

of design is largely associated with the architects, who in most building projects take up

the role of the lead consultants as they are the main source of the design used.

In Kenya, The architects usually follow a standard process of creating the design that

shall ultimately be built. The Architects and Quantity surveyors Act cap 525 (1978)

stipulates the design process by the Architect in 3 stages, as follows;

a) Pre-Design stage

b) Design and Documentation stage

c) Post contract stage.

2.1.1.1 Pre-Design stage

At this stage the architect usually engage the client in extensive consultations with the client. In

this stage, the building program or brief is interrogated in detail between the client and

consultants in order to create an accurate picture of the client’s requirements. Thorough

discussions is also be held with all stakeholders who will be part of the project, right from the

decision makers to the users of the spaces at the end of the day. For housing projects, architect

also prepares an accommodation schedule at the end of this process. This typically captures the

types of rooms to be created, their sizes and quantity if they are several in numbers, as well as any

special characteristics for each of these spaces. Such characteristics could include matters of

orientation, finishes and spatial qualities to be integrated in the spaces. (David, 2001)

At the Pre-design stage the architect will do the following;

a) Advice on the site selection

Every project requires to be thought of in context of its location and its surroundings. The

immediate environment of the project needs to be thoroughly considered when

commencing the design process. It is this that determines important design factors such as

viability of the site, orientation of buildings, access to the site and approach to buildings,

best views, among other issues. The architect will thus do a site analysis and studies to

identify the various parameters of the site and advice the client.

b) Site use studies

The architect will also perform a site study to understand the common use of the site and

analyze if it will satisfy the clients requirements.

c) Studies of services

Of particular concern to architect at this stage is also the existing infrastructure and services that

shall be integrated to a project. These include water and sewer connections and lines, electricity

supply, telephone and communications connections, as well as any other related services. The

state of physical roads determines the degree of difficulty accessing the site.

d) Zoning analysis and authorities consultations

A major factor that controls a project’s viability is the zoning by-laws of a particular location.

Zoning ordinances spell out the type and size of development that is allowable within any

particular locale, and is normally enforced by the local municipality or city council. Typical

zoning ordinances or bylaws include restrictions on minimum plot subdivisions and sizes,

maximum ground coverage, as well as maximum plot ratios. The plot ratio is a factor of the size

of the plot and hence defines the maximum size of building that one can build.

e) Finance and feasibility studies and reports

The financial viability analysis based on preliminary cost estimating and cash flow forecasts

prepared by the quantity surveyors, is considered in addition to physical and socio-cultural and

political factors of the proposed project. For example, a client would be ill advised to build a

residential bungalow in an area that allows building of office blocks. Better returns may be

achieved by constructing a project that fits its context in most cases.

Decisions as to whether a project is financially viable are usually taken by studying the market

trends of the area and confirmation with existing municipal by laws. At the financial level, the

team will confirm economic factors such as cost of financing, purchase or letting rates among

others. The architect and his design team can offer the client invaluable information regarding the

same to ensure they make an informed decision to proceed.

f) Soil investigations

This is mostly done to analyze and understand the nature of the substructure, it’s of great

concern to the structural team as they advise on the soil bearing capacity of the location

and hence the nature of the structure.

g) Project programming and analysis

This relates to the setting of the time limits for all the project dimensions to avoid loss of

control in matters of schedule. This includes timeline for preparations of the designs,

documentations, tendering and actual construction.

h) Preparation of briefs

Some of the Items in the project may be too technical for the client to understand, The

architect and his team on consultants will prepare detailed brief in form of a report clearly

outlining all the information that they deem the client should be aware.

i) Submissions for grants, subsidy and fund raising

This refers to the mode the client wishes to finance the project, through the advice of a

quantity surveyor, the client will decide on the budget he/she wishes to use on the project

so that the team of consultants go ahead and plan the project with the budget in mind.

j) Building procurement advice

The team of consultants and the architect will advise the client on the mode of tendering

and selecting the contractor for the project. The project timeline, Cost and desired quality

are considered in determining the mode of getting the contractors.

k) Equipment and plant procurement advice

Depending on project timeline, cost budget and desired, the consultants will advise the

client the kind of equipment and plant to use for the project. This will form the base for

technical evaluation of the contractors at the construction stage.

l) Administrative Services.

This involves documentation of the project reports, appointment of the support staff e.g.

Clerk of works and other administrative matters for the project.

2.1.1.2 Design and documentation stage

At the design and documentation stage, the architect will develop the designs as follows;

Outline proposal

These define the general design approach to be used in the project, the critical dimensions

and the main space allocations within the structure.

a) Schematic Design

These are draft drawings that are under continuous improvement and show the basic form

of the structure. From these drawings, the cost plan or budget is determined.

b) Design Development stage

At this stage, the schematic designs are refined and comprehensively analyzed to ensure

consistency in all the design i.e. architectural, structural and services.

c) Detailed design stage

During this phase, designs are refined to complete detail and the building can be

considered as working. Specifications are also laid out in detail to the client’s approval

and cost estimates earlier made are reviewed and adjusted as per these refined drawings

and specifications

d) Tender action

This includes the invitation of bids from different contractors; it depends on the method

of tendering desired by the team. Open tendering may be the best to get the lowest bidder

but its length, Selective tendering will be less time consuming but the selected contractors

may be very expensive hence leading to revision of the budget. Thus the architect and the

teams should understand all the project parameters when deciding on the tendering

method.

e) Additional services.

Depending on the condition of engagement between the consultants and the client, they

may be required to advice and offer additional services, e.g. the quantity surveyor may be

tasked with the responsibility of sourcing for finance from financial institutions.

2.1.1.3 Post Contract stage.

At the Post contract stage; the architect will;

a) Administering the contract

Administration of the contract and inspection of the works including, design, site

meetings (to a maximum of two meetings per month) as appropriate, supplying

information, checking claims and issuing certificates, negotiating variations and cost

adjustments and dealing with claims for extensions of time and other matters included in

the building contract.

b) Detailed supervision of the building process

The consultants will be providing regular, persistent and continuous supervision on site

during construction and ex-site during fabrication or assembly of parts. Where more

frequent or constant inspection is required a Clerk of Works can be employed. He will be

nominated or approved by the Architect or client, and be under the Architect’s direction

and control. He shall be appointed and paid by the Client or alternatively may be

employed by the Architect who shall be reimbursed by the client. Where the employment

of a resident architect is agreed, he will be employed by the Architect who shall be

reimbursed by the client. The team will also provide drawings showing significant

changes made in the work during construction, either re-drawn or marked-up drawings

and/or other data appropriate.

c) Records drawings, Maintenance and/or Guideline manuals

The consultants will also prepare as built drawings which will include all the changes

undertaken during the projects. The Consultants will also develop maintenance manual

and guidelines for the users to use it.

d) Commissioning assistance

At the end of a project, the consultants go through a process where the building reverts to

the total control and maintenance of the client/owner. This stage is referred to as

commissioning of a project. There are intensive inspections required at this level in order

to ensure that a building has been constructed according to the specifications that the

design team provided

e) Services during Defects liability period

The process of dealing with defects at the end of a construction is usually a major

challenge for the consultants. This process of laboriously inspecting the building to

ensure that there is no defective item on it must be thorough and ruthless. Following this

process, the Defects Liability Period which is also part of the post contract stage

commences. The consultant’s role is to ensure all the items on the snag list are attended

to satisfactorily by the contractor.

f) Administrative services.

This includes administrative matters that will ensure the building is ready for occupancy

e.g. acquisition of the occupancy certificate from the local council and completion of the

contractual matters with the contractor e.g. Settlement of the final account.

In conclusion, broadly put, the main stages are classified as the pre-contract stage where

the architect carries out design and documentation work, while in the post contract stage

the architect supervises the construction of the building project by a building contractor

according to their designs and specifications.

For this study, the concept of the design will be analyzed as per the 2nd stage, this is

because it’s at this stage that the designs will be developed and used at the construction

phase. In case of design changes, this will directly relate to what was proposed at the 2nd

stage.

2.1.2 Delivery of Construction Projects

According to Alaa and Garold (1993), there are generally two ways in which any

construction project may be delivered. This are

a) Design/Build

b) Design Bid and build.

2.1.2.1 Design and build method

Design/Build construction is the process where a company, provides a project with three

essential components: the initial design, the financial basis or budget and the

performance. The design/build firm provides the owner with the design and construction.

By giving the client what is in his or her best interest, the entire process is able to go

much smoother (Alaa and Garold, 1993). In this method, design changes are less likely

to happen as the designer and the contractor are one and the same.

Design/Build has some very essential points that all reflect a better overall project for the

owner. Budget is first determined by the general scope of the concept and comparing to

similarly completed projects. With knowledge of costs early and budgets set, unexpected

elevated costs cannot occur. More often than not, a set of independent plans that are

designed with little realistic thought or knowledge of true construction costs can exceed

an owner's expected costs by 60 or more percent (Robert, 1992). This, unfortunately, is

not found out until the plans are put out for bid. With design/build the design and

construction come under one contract, another plus for the owner. The designer or

engineer and the construction company are more unified and work together in

recommendations to the owner, another plus. Finally, this is usually the fastest method of

completing a project (Dennis, 1992).

The advantages of design/build are clearly evident. A reduction in the overall time is very

important. Less time and fewer meetings are required. Owners need not spend as many

meetings first with their designer and engineer and then another set of meetings with their

selected contractor. Budgets are set early and costs are not an uncertainty during the

design. Fewer problems arise because the project is so well defined. This also relates to

no change orders unless there is a legitimate change in the scope. All these advantages

help the owner receive a project on time, at budget and as expected (Alfred and Dellon,

1986).

This approach has become more common in recent years and involves the client contracting a

single entity to both provide a design and to build that design. In some cases, the Design and

Build (D & B) package can also include finding the site, arranging funding and applying for all

necessary statutory consents (Edward D. Leidholt, 1977). The owner produces a list of

requirements for a project, giving an overall view of the project's goals. Several Design and Build

contractors present different ideas about how to accomplish these goals. The owner selects the

ideas he or she likes best and hires the appropriate contractor. Often, it is not just one contractor,

but a consortium of several contractors working together. Once a contractor or consortium has

been hired, they begin building the first phase of the project. As they build phase 1, they design

phase 2. This is in contradiction to a design-bid-build contract, where the project is entirely

designed by the owner, then bid on, then completed.

2.1.2.2 Design, Bid and Build

In Design, bid and build method, Separate groups perform the completely different but

intertwined parts of the process. The Architect and other consultants, after receiving the

ideas and requirements from the client/owner, create a set of plans and specifications.

These are then provided to several general contractors through a bidding process. One of

these contractors is then selected by the owner based on the lowest bid and best technical

evaluation. This method of selection is very unfortunate since all the bidders concentrate

on their own interests, instead of that of the owners. Every short cut, advantage, minimal

construction problems, quality of material and possible variations for future revenues are

the main considerations from all the bidders in providing the low bid.

The plan and bid method also means two separate contracts for the design and

construction. This limits the client to little more than litigation if problems arise.

Responsibility and causes of design changes may become a clouded issue between

designer and contractor when they are separate. This also has the architect and contractor

each having their own ideas concerning the plans, methods and specifications. Finally, it

is the slowest way to complete a project. By separating the design from the construction,

the time line is greatly expanded (Charles, 1987).

Dr. Keith (1987) in the study of the construction and replacement of 5 bridges in different

parts in European countries using the design build system as an alternative to design, bid

and build system of project delivery noted that there is a time saving element and a more

easier way of project delivery. He developed the following figure is his explanation of the

time savings achieved using the design build compared to design, Bid and Build methods

of project delivery.

Figure 2.1. Design-build versus design-bid-build

Source: Dr. Keith Molenaar (1987)

In the Kenyan construction industry, the architect acts as the Lead consultant and sometimes as

the project manager. His or her role is to design the works, develop the specifications and produce

the drawings, administer the contract, tender the project, and manage the works from inception to

completion (Edward, 1988). There are direct contractual links between the client and the main

contractor, through the architect. In case the project has a subcontractor, they will have a direct

contractual relationship with the main contractor.

2.1.3 Design Changes

A change is defined in literature as any deviation from an agreed upon defined scope and

schedule. Stated differently a change is any modification to the contractual guidance

provided to the contractor by the owner or owner’s representative (Fisk, 1988 and Yu,

1996). This includes changes to plans, specifications or any other contract document. A

change order is the formal document that is used to modify the original contractual

agreement and becomes part of project’s documents.

Initially, the contractor receives the contract package in the form of plans, drawings,

specifications and other documents. This constitutes the basis of his proposal. Contractor

will calculate and bid based on this original package. Obviously any changes to this set of

documents will alter his plans and calculations.

Changes can be initiated by all parties in the construction process. All changes however,

must be approved by Owner or his representatives before implementation. According to

JBC condition of contracts for building works (1999), any alteration or modification of

the design, quality or quantity of the Works as shown upon the contract drawings and

described by or referred to in the contract bills and specifications is referred to as

Variation. A change order can also be issued through an architect’s instruction during site

inspections or meetings, however, all instructions issued by the Architect shall be in

writing. Any instruction issued orally will be of no immediate effect, but will be

confirmed in writing by the Contractor to the Architect within seven days. If not

dissented from in writing by the Architect within seven days from receipt of the

contractor’s confirmation, the oral instruction will take effect as from the expiration of

the latter said seven days (JBC conditions of contract for building works, 1999).

2.1.4 Causes of Design Changes

In this section we examine the potential causes of change design orders in construction

projects in general and large building projects in specific expected in this survey.

In a study by Luis and Daniel (1998) of for different projects in the republic of Chile,

they come up with a Pareto’s classification of design defects that result to design changes

as detailed below.

Table 2.1 Pareto’s Classification of Design DefectsNo. Design defects Weight

(%)AccumulatedWeight (%)

1 Structure Elements Details 13.97% 13.97%2 Lack of Architecture Detail Plans 12.78% 26.75%3 Incorrect Cross References Between Different

Specifications11.59% 38.34%

4 Incorrect Structures Cross References 8.17% 46.51%

5 Lack of Definition of Architecture Elements 6.54% 53.05%6 Structure-Bid-Plans Modifications 6.39% 59.44%7 Lack of Architecture Dimensions 6.24% 65.68%8 Lack of Identification and Location of Architecture

Elements5.65% 71.32%

9 Finishing Materials that Require Samples 4.75% 76.08%10 Shaft Problems 4.46% 80.53%11 Design Defects in Sewerage and A.P. 4.16% 84.70%12 Architecture's Incorrect Cross Reference 3.12% 87.82%13 Design Changes by the Owner 3.12% 90.94%14 Electricity Design Defects 2.97% 93.91%15 Structure Plans Late Delivery 1.93% 95.84%16 Defects in A. C. Designs 1.49% 97.33%17 Problems with Electrical Equipment 0.89% 98.22%18 equipment’s Structure 0.59% 98.81%19 Problems with the Materials in the Market 0.45% 99.26%20 Symbology Conventions 0.45% 99.70%21 Gas Design Defects 0.30% 100.00%Source: Improving the design-construction interface by Luis and Daniel 1998.

The following are a summary of the common design changes causes as reviewed from a

study of Burati, et al (1992).

2.1.4.1 Change of Plans by Owner

In a study by Burati, et al (1992), Change of plans or scope of a project is by far the most

significant cause of changes in construction as stated in the literature. Normally this

source of changes results because of insufficient planning at the project definition

stage or simply because of the lack of involvement of the owner at the design stage.

This type of changes is normally costly especially if made later in the construction

process. An example of change of scope or change of plans is the increase in building

area, an increase or decrease in the number of floors. Early involvement of the owner in

the project objective definition and later in the design of the facility normally reduces

such changes to a minimum.

2.1.4.2 Owner Financial Difficulties

The owner of the facility may run into difficult financial situations that force him to make

changes in an attempt to reduce cost. The fact that many of the owners in this country

especially in large building construction projects are wealthy individuals who might not

have sound and reliable financial sources makes this risk a real one. Again proper

planning and review of the project cash flow is enough to eliminate this problem.

2.1.4.3 Owner Change of Schedule

The owner might change the schedule of the project, which might cause a change in the

design to be constructed so as to fit in the desired schedule. However, time has an

equivalent money value. This makes changes in the schedule as costly as change in scope

or materials. As the contract was signed the contractor has leveled his resources over the

time frame agreed upon with the owner. A change in the schedule means the contractor

will either provide additional resources in a shorter time or idle some sources that he

committed for certain activities. In both cases additional cost is incurred. Although there

are numerous causes of schedule change such as market conditions, user requirements, or

lack of funding, the owner must be certain that the cost of change of schedule is well

covered by the anticipated benefits.

2.1.4.4 Defined Project Objectives

This might be a sub-category of change of plans but specifically indicates that the

objectives of the project were not well defined. This will sure cause a change in the

design at a later stage of the project.

2.1.4.5 Substitution of Materials or Procedures

If the contract calls for certain materials or work procedures, then a change order is

required to substitute these materials or procedures. This is especially in the large

buildings, where material standardization is not common and some of the materials will

need to be imported, e.g. Aluminum cladding. The substitution of materials or the

procedure of construction may necessitate a change in design to accommodate the

substitution.

2.1.4.6 Conflict between Contract Documents

Quite often, different documents are drawn by different engineers or design personnel

during the design phase of the project. In spite of the close coordination between design

personnel or disciplines, discrepancies are sometimes found. Normally contracts include

guidelines as to which document governs in case of conflict. However the owner may

find out that the governing document representation or requirements are not the best and

may decide to change. Owner must expend sizable effort to review contract documents

for any possible contradictions before award of contract to avoid such changes. Phrases

that can be interpreted differently have to be rewritten if confusion is to be avoided. The

contractor will normally look for any phrase or note in the contract documents to

justifying the cheaper option.

2.1.4.7 Change in Design

The changes in design happen more in projects where construction starts before design is

finalized or in concurrent design and construction. The owner may opt for such a

philosophy if the project is schedule driven and time is the controlling element. Owners

normally object to any changes in design at this stage. However a new element of design

may not have been considered before or a clear design advantage that is assumed by the

change may favor going ahead with implementing this change. Change in design may

also take place when the design is reviewed by the consultant, who has a different

opinion than the designer, and he may wish to make changes. The owner or project

manager should be careful however of approving preferential changes.

2.1.4.8 The Scope of Work for the Contractor is defined

Here the change is not forced because of change of a mind by the owner as we noted

earlier, but rather because of lack of clarity in the documents about the scope of work.

This might happen for example when work is contracted to different contractors but the

boundaries are not made clear. It takes quite extensive efforts to draw the boundary lines

between different packages or phases of the same projects especially in large complex

projects where all systems are virtually interconnected. Clear demarcation on drawings

besides clarifying notes is a must to avoid such situations. In many instances, the owner

contracts a third party to do work that he thought was included but cannot prove it was.

2.1.4.9 Errors and Omissions in Design

It is impossible to create a 100% error free design. Quite often, among the many

documents of the project, one will find a note deleted, a detail mis-referenced or an

incomplete specification sheet. The contractor’s point of view is to escape the extra cost

and will look for ways to minimize cost. This is quite legitimate and justified. In this case

the owner will pay the extra cost (design change) or accept an inferior product or design.

A quality assurance program in the designer office should minimize this source of

changes.

2.1.4.10 Lack of Coordination

It is quite important in a multi-player environment like a construction project to keep

strong and continuous coordination. The owner should convey his new ideas and

concerns which form the basis for changes to the consultants in a timely manner. The

owner should avoid giving direct orders to the contractor without the involvement of the

party who is acting on his behalf. The consultant has to update the contractor of any

concern he might have with the scheduled work. If we keep in mind that changes have an

exponential relationship with time, we do not need to stress this point any further. Ways

to improve coordination include coordination meetings, progress reports, and conference

calls among others.

2.1.4.11 Technology Changes

Major construction projects and especially those which have technology items might face

this reason for change especially if the time between design and construction is long. The

presence of new technology in the market, a new desalination unit or a new erection

method might encourage the owner or the consultant to initiate this type of change.

2.1.4.12 Differing Site Conditions

This cause of changes happens most of the time on soil conditions in building

construction. The contractor may face rock instead of soft soil as the tender document

may have indicated. This will require extra effort for excavation and extra compensation

to the contractor.

2.1.4.13 Contractor Desire to Improve his Financial Conditions

Although no contractor wants to admit it, changes are looked at as a source of

additional work. The contractor may talk directly to the owner and convince him to do

certain changes only to give himself the additional benefit of change work. The

contractor may take any excuse to claim that certain parts of the work are not in his scope

and therefore request compensation for doing it.

2.1.4.14 Unavailability of Skills (Shortage of Skilled Labor)

Certain jobs may require certain expertise that is not available in the local market and for

that reason the owner or consultant may agree to modify the method or procedure of

construction. This type of change is more likely to happen in construction involving some

degree of technological complexity and not in normal building construction.

2.1.4.15 Unavailability of Equipment (Lack of Equipment)

Like the previous source of change the lack of a piece of equipment may force a change

to the plan. For example, lifting of some heavy structure may require crane capacity that

is not available in the country forcing the contractor to think of other lifting methods. The

danger in this comes from the fact that some designs are done outside the country by

companies not familiar with the resources available locally. Active participation of

the owner during design will minimize this source of changes.

2.1.4.16 Defective Workmanship

Defective workmanship of completed work may bring about demolition and re-work or

may bring about changes in some instances. Acceptance of defective workmanship due to

schedule may force a change in the facility to correct for it.

2.1.4.17 Safety Considerations

If some safety aspects were overlooked during the design phase, the owner or

consultant may initiate a change to install additional safety features in the facility. This

cannot be different from any other design oversight, except for the fact that safety is

usually un-compromised. The addition of specific safety controls such as a relief valve in

an industrial facility or an escape door in a building is typical of such changes.

2.1.4.18 New Government Regulations

Local authorities may have specific codes and regulations that must be adhered to.

Normally the designer insures that his design is in compliance with these codes.

However, new regulations may be issued between design and construction and may force

some changes to the original plan. Codes such as environmental or labor codes are

revised periodically and the contractor or facility owners are requested to comply.

2.1.5 Effects of Design Changes

There are numerous effects brought about by design changes and change order

in construction. In this section we examine some of these effects which are

commonly encountered.

The impacts of changes are not understood and rarely recognized, in terms of costs and

schedule. The work hours invested by the designers in the changes have been estimated

in a 40 to 50% of the total of a project (Koskela, 1992). In Latin American countries, it is

estimated that between 20 to 25% of the total construction period is lost as a product of

design deficiencies (Undurraga, 1996). On the other hand, for some Chilean construction

companies, the principal source of conflict in projects are the continuous changes in the

designs carried out by the owners, affecting quality and productivity and impacting the

schedule and the cost of the projects.

2.1.5.1 Decrease in Productivity

In a study by Thomas and Napolitan (1995) productivity values from three industrial

projects constructed between 1989 and 1992 were used in the analysis. The study

concluded that on average there was 30% loss of efficiency due to changes (25-50% was

the actual range). It is worth noting that Thomas and Napolitan concluded that changes

do not lead to productivity degradation or efficiency loss in themself. Instead, a

construction change causes other disruptive influences to be activated. In fact, Thomas

and Napolitan concluded that it is possible to perform changes without negatively

impacting labour efficiency. However, it is difficult to qualify this statement. Changes are

disruptive in nature and to think of eliminating some of these disruptions is impossible

before the change is introduced.

2.1.5.2 Delay in Completion Schedule

It is easy to document a schedule impact of a change after change work is done, because

all data is available regardless of its accuracy. However, it is difficult to predict impact of

change on schedule before making a change because of the many uncertainties related to

labour productivity, material availability or job interference. The cost of schedule

slippage becomes very high if the contract includes a penalty clause. Most projects are

planned using a critical path method, CPM, (CII publication 6-10, 1990). This method of

scheduling shows the activities included and their dependencies. CPM provides the basis

against which impact of changes on schedule can be evaluated. Floats both total and free

play an important role in schedule impact evaluation for they represent the flexibility

available to handle the unforeseen conditions such as changes.

The magnitude of schedule slippage due to changes is reported by Zeitoun and

Oberlender (1993) as 9% of the original schedule on average for 71 fixed price projects

studied.

2.1.5.3 Dispute between Owner and Contractor

Changes and change orders are among the most common reason leading to claims and

disputes. All other work is agreed upon in the contract. However changes must go

through evaluation, estimation and negotiation leading to stress and strains in the relation

between parties. If these disputes are not settled peacefully through direct

negotiations and arbitration they end up in court and legal procedures may suspend the

whole project (James, 1984).

2.1.5.4 Decrease in Quality

Sometimes changes lead to a lower level of workmanship. As changes alter the original

plan in certain items or areas, they might create a mismatch with other items or areas

affecting the overall quality of the work. As discussed above, the low morale of the crew

after many changes are made is also expected to affect the quality of their

performance (Kevin, 1983).

2.1.5.5 Increase in Project Cost

To make a change and process takes time. This usually results in placing a hold on the

work and waiting for new instructions to come. In addition, equipment, tools and

materials may not be the same after the change is introduced. To procure or rent new

material, tools and equipment will cause delay and cost of resources may be substantial.

Furthermore, if delays are prolonged demobilization/remobilization may become quite

costly.

2.1.5.6 Additional Money for Contractor

No matter how much was said about the negative effects of change orders, there is often

additional money gained by the contractor for executing additional scope

(Krone,1991). The accuracy of this statement depends on the awareness of contractors

and owners of direct and indirect impacts of changes and on the willingness to accept this

fact in change order pricing.

2.1.5.7 Delay of Material and Tools

Change orders bring about problems with materials and tools required to carry out a

certain activity. Consider for example an order to change the type of doors of a building

at a time after the order for doors was issued to the vendor. The new type of doors may

not be available from the vendor and may require extra time to order or fabricate. This

creates delay for materials which in turn holds up work for finishing subsequent work

(Algimantas, 1998). The delay of tools happens for example when a certain erection

procedure has changed requiring a larger crane that is not readily available. The cost of

such a delay can be quite costly.

2.1.5.8 Work on Hold

Change in a certain work package can put the work on other activities on hold. This

happens when activities are interdependent. This action may freeze a certain craft crew or

shift the schedule of its schedule. Speedy and quick change order procedures are very

vital in order to minimize this effect (Gilbreath, 1992).

2.1.5.9 Increase in Overhead Expenses

Normally change orders require processing procedures, paper work and reviews before

they even proceed. They may require use of funds that otherwise will be used for other

activities. These minor expenses are normally not charged to the change order account as

they are difficult to define and separate from the different accounts (Cox, 1997). The

charge normally goes on the contractor’s overhead account.

2.1.5.10 Delay in Payment

If payments due to the contractor are made against a certain milestone then there is a

possibility of delay in payment as a result of a change that delays the achievement of that

milestone.

2.1.5.11 Demolition and Re-work

Quite often, changes that occur after construction of the project cause some parts of the

work done to be demolished and done again. This is the worst phase to think of changes

and the cost of changes is the highest on the project time curve. JBC condition of contract

for building works (1999) state that no instructions for variations shall be issued after the

practical completion certificate is issued without the consent of the Contractor.

2.1.6 Control Tools used to handle Design Changes

In this section we will review the common control procedures used to minimize the

effects of change orders. These include measures taken prior to the start of construction

and before generation of change orders and measures taken to minimize impact of change

orders after they have been generated.

2.1.6.1 Clarity of Change Order Procedures

Every project team must ask these questions before the kickoff of the project in relation

to design changes:

a) Are the procedures to handle changes clear to all parties?

b) Are the forms and instructions to complete them available?

c) Are the people responsible for approving, negotiating, and reviewing changes

identified?

The clarity of these procedures at the beginning of the job will save a lot of time and

effort. (Kuprenas, 1998).

2.1.6.2 Quick Approval

The time between recognizing the need to make a change and actually doing the change

can be days or months. The longer the period between recognition and implementation,

the more costly the change is. Because of the dynamics of construction projects, work

impacted by changes increases as the project progresses to a more detailed phase

(Cooper, 1995). This control is quite important in large organizations or large projects

and a multi- player environment.

2.1.6.3 Ability to Negotiate Changes

There are certain skills required to be able to negotiate change orders. Knowledge of

contract terms, project details, technical background in the field, and negotiation skills

are required to come to a successful agreement on change orders (Emory, 1995). Lack of

any of these skills may complicate the negotiation and lead to disputes, delays or making

the wrong decision.

2.1.6.4 Approval in Writing

Changes should not be made without approval in writing. It is difficult to prove the right

for compensation if there is no authorization in writing from the owner (Rowland, 1981).

Even the JBC condition of contractor for building works (1999) insist that all instructions

given by the architect and the owner to the contractor, which will lead to a variation or a

change, be in writing. In the hectic environment of construction many verbal agreement

can be forgotten leaving the contractor disarmed in the battle to get compensation for a

change.

2.1.6.5 Change Order Scope

Like the original scope of a project, the scope for a change must be clearly defined.

Affected drawings must be reviewed to insure the extent of construction or demolition

and to see the effect of this change on other parts of the facility. This gets critical when

working in a renovation project where there is a constant interface with existing structure

(Robert, 1990).

2.1.6.6 Pricing of Indirect Effects

We have seen in our literature review that changes have direct as well as indirect effects

on projects. Often indirect effects are not accounted for. In simple projects this might not

be a problem. However indirect effects can be substantial in more complex projects.

These effects include effects on labor productivity, additional bonding and

insurance, extra overhead expenses, shift of schedule to a less favorable period,

etc. Pricing of change orders must consider these factors to come up with fair

compensation (Saudi, 1995).

2.1.6.7 Justification of Changes

Any change request must be carefully examined to insure there is enough

justification. Knowing the problems associated with construction changes, the authority

that approve change must insure a high benefit to cost ratio to precede with the change

(Rowland, 1981). An extra effort must be exerted to determine the extent of the effect of

a change on scope, cost, material, finance etc. before approval.

2.1.6.8 Review of Contract Documents

Owners and contractors must review contract terms and documents prior to bidding

or award. In many instances, specific teams are formed to carry out this review. Improper

use of change potential in the document can cost a lot. Special attention must be given to

gray areas where different interpretation can arise (Bruce, 1999). Clarifications shall be

made as early as possible to the particular vague part of documents. In many cases, it was

seen that unanswered question is carried over from the conceptual development of the

project all the way to construction phase.

2.1.6.9 Freezing Design

Many owners consider this measure after feeling that the design has developed to a

satisfactory level. This is quite effective in a large multi-departmental owner

organization. (Stephen, 1992) In such a case each department may continue to request

modification to the scope. By using this scope control procedure, the owner is

committing himself to a comprehensive review at early stages of the project.

2.1.6.10 Team Effort

Many researchers have concluded that team effort minimizes impact of changes.

Encouraging teamwork is considered an effective control in change management. This

approach requires that all parties (owner, contractor ,and consultant) work together to

identify and implement project changes and openly share information on pricing and

implementing of changes (John, 1991).

2.1.6.11 Use of WBS

As discussed in the literature review, an effective means of tracking the cost of change

orders is the use of Work Breakdown Structure (WBS). This technique allows the project

management to see the effects of a change happening in a certain work package on other

work packages represented in the WBS tree (Weston, 1991).

2.2 CONCLUSIONS

A lot has been written on the field of design changes in the construction industry with

many different writers giving different perspectives to it. Schools of thought are

developing with some conflicting with each other, while some just modify existing ones

especially on the causes and effects of design changes in the construction industry. The

above review attempted to highlight the common grounds between the various scholars

on the focus area of the study.

Control of construction projects on the other hand, is a fairly standard activity and

consists of laid down principles which different people attempt to follow. Hence, there is

very little variation of thought among different writers on the field. These principles have

been tried over time and their effectiveness in controlling design changes was reviewed.

The identification of the causes of design changes, its effect on the control of

construction projects and the different control tools used to mitigate its effect was as a

result of the synthesis of the three areas of study.

CHAPTER THREE

RESEARCH METHODOLOGY

3.0 INTRODUCTION

This chapter will focus on giving details on how the research was done. It focuses on the

determination of research design, the type and sources of data, research population,

sampling design, data collection, data collection instruments, data analysis, adherence to

research ethics and research reporting. The chapter will also address the difficulties that

were faced by the researcher during the study.

3.1 RESEARCH DESIGN

Research design is a strategy used in collecting and analysis of data in order to answer

research questions and test research hypothesis. The research design that was used in this

study is descriptive design. According to Kothari (2004), descriptive research design is

the arrangement of conditions for collection and analysis of data in a manner that aims to

combine relevance to the research purpose with economy in procedure. In fact, research

design is the conceptual structure within which research was conducted; it constituted the

blueprint for the collection, measurement and analysis of data. As such, the design

included an outline of what the researcher did from writing hypothesis and its operational

implications to the final analysis of data.

3.2 STUDY POPULATION AND DESCRIPTION OF THE STUDY AREA.

Study population is defined as the aggregate of all study unit, they have a potential for

providing relevant data for the study. A particular population has some characteristics

that differentiate it from other population. The research targeted the Nairobi County. The

study area was preferred because most construction activities involving consultants and

contractors take place in Nairobi as opposed to any other part of the country. Besides,

most of the consultants in the study were concentrated in the area. Sources from the board

of registration of architects and quality surveyors (BORAQS) demonstrated that about

75% of the total population of consultants is based in Nairobi. The study area was also

chosen because of its proximity to the researcher, and also due to constrain of time and

money. It is however assured that the findings from the research gave an overview of the

entire construction industry all over the country.

3.3 TARGET POPULATION

Mugenda (1999) refers to population as an entire group of individuals, events or objects

having the common observable characteristics to which the research wants to generalize

the result of the study. The target population under study was professional practicing

firms in the construction industry in Kenya. They include contractors and consulting

quantity surveying, architectural and engineering firms together with the developers who

were involved in the projects. The accessible population includes developers/clients,

contractors and the consultant team of projects approved by Nairobi city council (NCC)

for the year 2011 and 2012. According to the minutes of proceedings of approved

building plans from the Nairobi city Council, department of development control, 8125

building plans were approved for development in the year 2011 and 2012. The study,

however, considered large construction projects with an estimated cost of over 100

million, this, according to the minutes, resulted to a population of 488 projects. Some of

the developers, contractors and consultants had more than one project. The target

population of developers, Architect, Engineers and the contractor were identified as

below tabulated;

Table 3.1 Target PopulationFirms Target Population (n) Percentage

Developers 162 30

Consultant 112 21

Engineering 113 21

Contractors 148 28

Total 535 100Source: NCC minutes of proceedings from 2011 to 2012

3.4 SAMPLING DESIGN

Due to the big size of the research population there was a need to do sampling. It was

impractical to carry out a study in an organization with a population of 535 due to time

and financial constraints. Sampling allowed the researcher to collect data from a

representative size of the target population.

3.4.1 Sampling Method

The sampling method that was used in the study is probability sampling. This is the

appropriate method of sampling because it involves random sampling which gives all the

members of the research population equal chances of being represented in the study. This

method is not biased and therefore produces a sample size that is representative to all the

firms of the study population.

3.4.2 Sampling Technique

Stratified random sampling technique was used in the study. The technique was used

because it ensures that all the firms in the target population were represented. It will be

possible to find a representative sample size for the study using this technique because

the study area on which the study was carried out has four categories that will be

classified as strata during the study.

3.4.3 Sampling Procedure

The sampling frame for this study was the developers, contractors and consultants in

Nairobi County. After identifying the target population, the investigator selected a sample

out of the target population. The sample size will be determined using the following

formula for descriptive study:

n = z2pqN

e2(N-1) + z2pq

Source: Chara and Nachamias (1996)

Where;

n= Sample required from the population

N=Population size (535)

z= Standard normal deviate corresponding to 95% level of confidence= 1.96

p=Sample population estimated to have characteristic being measured.

q= (1-p)

e=Margin of error set at 5 %

Substituted:

The sample size was thus arrived at as follows;

n = (1.96)2 x 0.95 x 0.05 x 535

(0.05)2 x (535-1) + (1.96)2 x 0.95 x 0.05

Sample size (n) = 64.33 approximately 65

Sample size percentage = 65 x 100

535

= 12.15%

Sample size = Sample Size Percentage x Target Population

Developers = 12.15% x 162

= 20

Architects = 12.15% x 112

= 14

Engineers = 12.15% x 113

= 14

Contractors = 12.15% x 148

= 17

Table 3.2 Sample SizeFirms Target

Population (n)Sample Size

Developers 162 20

Lead consultant (Arch. Or QS,PM) 112 14

Engineering 113 14

Contractors 148 17

Total 535 65

Source: Author (2013)3.5 DATA COLLECTION

The type of data that was used for the study is primary. This is the first hand data that

was collected directly from the field. The study primarily used first hand data collected

directly from the respondents. Secondary data was used as reference material sourced

from past research studies, textbooks, journals and articles.

3.5.1 Method of Data Collection

Questionnaire method will be used in data collection for the research study. The size and

nature of the research population demands that a fast and confidential method of data

collection be used in the study. Non-verbal means of questioning will be used in order to

enhance the confidentiality of the data collected.

3.5.2 Instruments of Data Collection

The instrument of data collection that was used in the study is questionnaires. These are

written forms comprising of a set of questions that will be used to gather the data required

from a sample population. Each item in the questionnaire is developed to address the

research objectives. Unstructured and structured questions were used in the research

study.

3.5.3 Data Collection Procedure

The questionnaire contains a set of closed and open ended questions. Open ended

questions will give the respondents complete freedom of response which allows them to

respond in their own will and express what they consider important. The questionnaires

will be prepared and delivered to the respondents by the researcher. The researcher will

agree on the period during which the questionnaires will be filled and dropped back to the

researcher.

3.6 DATA ANALYSIS

The data collections instruments was collected and verified if they are dully filled by the

respondents. Questionnaires that did not have 80% of the questions answered were not

included in the analysis. The collected data was classified, coded, corrected, analyzed and

then interpreted. Both qualitative and quantitative methods were used for the analysis.

3.7 DATA PRESENTATION AND ANALYSIS

The data obtained by the use of the questionnaires was interpreted in relation to the

information obtained from the literature review with regard to the causes, effects of

design changes on the control of construction projects and control tools used to mitigate

the effects. This was then summarised in the form of tables, graphs and pie charts

depending on the type of data and the suitability of the mode of presentation for the same.

The data was analysed by considering each of the questions contained in the

questionnaire and the frequencies noted for the responses to each of them. These were in

the form of percentage distributions. From these responses, the researcher gauged the

effects of design changes on the control of construction projects in Kenya.

In doing this analysis and presentation, the researcher made extensive use of the MS

Excel office application.

CHAPTER FOUR

RESEARCH FINDINGS

4.0 INTRODUCTION

This section presents the research findings beginning with response rate and demographic

information of the respondents. The other sub-sections were presented based on the study

objectives. These were to establish the effects of design changes on the control of

construction projects in Kenya; case study of Nairobi

4.1 RESPONSE RATE

The table below shows the response rate

Table 4.1: Response Rate

Firms Number of respondents Non-response

Frequency % Frequency %

Developers 20 31% 0 0%

Lead

consultants(Arch,QS,PM)

10 15% 4 7%

Engineering 14 21% 0 0%

Contractors 15 23% 2 3%

Total 59 90% 6 10%

Source: Fieldwork 2013

The table shows that after the data collection 59 questionnaires were filled and returned

for analysis giving a response rate of 90% and 10% non-response rate. These were

distributed as 20 (31%) from Developers, 10 (15%) for Lead consultants, 14 (21%) from

Engineering and 15 (23%) from Contractors. This commendable response rate was

realized as a result of the researcher’s plea to the respondents on maximizing on data

collection and making follow ups to ensure that the data collection process was carried

out as planned. Most of the respondents were people of significance and vested interest in

the study area and this ensured credibility of the data collected.

Figure 4.1 Response rate

Source: Fieldwork 2013

4.2 DEMOGRAPHIC INFORMATION

4.2.1 Information on line of business/Profession

The first item on the demographic information sought to group respondents according to

their line of profession/business the following Table 4.2 indicates the distribution of

respondents according to their line of business.

Table 4.2 Line of business/profession

Line of Business Frequency Percentage%

Architect 4 7%

Quantity surveyor 3 5%

Engineer 14 24%

Contractor 15 25%

Developers 20 34%

Project Managers 3 5%

Total 59 100%

Source: Fieldwork 2013

The table shows that there were 4 (7%) Architects, 3 (5%) Quantity surveyors, 14 (24%)

Engineers, 15 (25%) contractors, 20 (34%) Developers, 3 (5%) Project Managers this

shows that majority of the respondents were Contractors which constituted 34% of the

total respondents while Quantity surveyors and Project Managers bottomed the list with

3% respectively. However, Most of the developers were persons of influence on the

subject matter including architects, Quantity surveyors and other professionals who

engage in property development as their line of business. This ensured that they had full

knowledge of the study area and thus credible.

Figure 4.2 Line of business/profession

Source:Fieldwork 2013

4.2.2 Information on Duration of service on the respective line of profession

The table below 4.3 indicates the distribution of respondents according to their duration

of service in the respective line of profession.

Table 4.3 Duration of service

Duration of service Frequency Percentage%

Less than 5 years 22 37%

5-10 years 11 19%

Over 10 years 26 44%

Total 59 100%

Source: Fieldwork 2013

From the table above 26 (44%) of the respondents have served for over 10 years,

followed by 22 (37%) respondents having served for less than 5 years, and 11 (19%)

respondents to the study have served for period between 5-10 years. It’s therefore

appropriate to understand that most of the respondents to this study have served in their

respective line of profession for over 10 years.

Figure 4.3 Duration of service

Source: Fieldwork 2013

4.2.3 Information on the position of the respondents in the organization

The table below 4.4 indicates the position of the respondents in the organization

Position in the Organization Frequency Percentage%

Director/Principal partner 21 36%

Associate partner 14 24%

Senior staff 18 31%

Employee 12 20%

Source: Fieldwork 2013

From the table, 21 (36%) of the respondents were Directors/principal partners, 18 (31%)

of the respondents were senior staff, 14 (24%) of the respondents were Associate partners

and 12 were employees (20%). It can therefore be derived that Majority of the

respondents were Directors/principal partners which represented 36% of the total

respondents. There were no other respondent with any other specifications other than the

mentioned positions.

Figure 4.4 Position in the organization

Source: Fieldwork 2013

4.2.4 Information on the Professional Associations attached to the

respondents

The table 4.5 indicates the professional association and organisation attached to the

respondents.

Professional association Frequency Percentage%

AAK 12 20%

IQSK 8 15%

ICPMK 7 12%

IEK 12 20%

KFMB 15 25%

BORAQS 2 3%

None 3 5%

Total 59 100%

Source: Fieldwork 2013

From the table 15 (25%) of the respondents were attached to KFMB, all of them being

contractors, 12 (20%) AAK, 12 (20%) 1EK, respectively, 8 (15%) IQSK, 7 (12%)

ICPMK, 3 (5%) of the respondents did not belong to any of the professional associations,

while 2 (3%) of the respondents were attached to BORAQS.It can therefore be observed

that majority of the respondents 25% were attached to the KFMB while 5% of the

respondents were not attached to any of the associations. Some of the respondents

belonged to both IQSK and AAK.

Figure 4.5 Professional association

Source:Fieldwork 2013

4.3 INFORMATION BASED ON THE STUDY OBJECTIVES

4.3.1 Information on whether the Projects involved have experienced

changes in the initial design.

The table below shows the response of the respondents on whether the projects they were

involved in have experienced some changes in the initial design; the results of the

findings were represented as shown in the table 4.6 below:

Response Frequency Percentage %

YES 57 97%

NO 2 3%

Total 59 100%

Source: fieldwork 2013

From the table 57 (97%) of the respondents have experienced some changes in the initial

design in the projects they were involved in while only 2 (3%) of the respondents did not

experience any changes in the initial design of the projects they were involved in.

Figure 4.6 Response on the changes on the initial design

Source:Fieldwork 2013

4.3.2 Information on how the respondents ranked the causes of changes in

the initial design.

The table 4.7 below shows how respondents reacted to the causes of design changes; it

shows how the respondents scaled their responses as shown

Causes of design changes Neutral Slightly agree Strongly agree Total

Initiated by the users/clients /owner 0 24 (41%) 35 (59%) 59

Architect/consultant originated 0 36 (61%) 23 (39%) 59

Contractor originated 0 40 (68%) 19 (32%) 59

Lack of coordination in the project 0 42 (71%) 17 (29%) 59

Differing site conditions 0 38 (64%) 21 (36%) 59

New government regulations 12(20% 24 (41%) 23 (39%) 59

Source: Fieldwork 2013 (Key 3=Neutral 4=slightly agree 5=strongly agree)

From the table 24 (41%) of the respondents slightly agreed that changes of the initial

design were initiated by the users/clients/owners, while 35 (59%) of the respondents

strongly agreed on the same.36 (61%) of the respondents slightly agreed that changes of

design were initiated by the Architect/consultants while 23 (39%) of the respondents

strongly agreed that changes on the design were caused by the Architects/consultants.40

(68%) of the respondents slightly agreed that changes on design were initiated by the

contractors while 19 (32%) of the respondents strongly agreed that changes in the design

were initiated by the contractors.42 (71%) of the respondents slightly agreed that changes

on the design were as a result of lack of coordination in project team members,17 (29%)

of the respondents strongly agreed that changes in the initial design were caused by lack

of coordination in the project team members.38 (64%) of the respondents slightly agreed

that changes in the initial design were caused by the Differing site conditions while 21

(36%) of the respondents strongly agreed that changes in the initial design were caused

by the same. Finally 12 (20%) of the respondents had a neutral stand that changes in the

initial design were caused by the New government regulations 24 (41%) slightly agreed

while 23 (39%) strongly agreed on the same. There were no other specifications made

outside the causes of initial design provided to the respondents.

Figure: 4.7 Causes of the design changes

Source:Fieldwork 2013

4.3.3 Information on how the respondents ranked the effects of design

changes in construction projects in Kenya

The table 4.8 below represents the findings on how the respondents ranked the effects of

design changes in construction projects in Kenya

Effects of the design change Low Average High Total

Delay in the completion schedule (time

overruns)

0 (0%) 17 (29%) 42 (71%) 59

Increase in project cost (cost overruns) 0 (0%) 13 (25%) 44 (75%) 59

Decrease in productivity 32 (54%) 15 (25%) 12 (21%) 59

Dispute between the project team members 24 (41%) 26 (44%) 9 (15%) 59

Demolition and rework 0 20 (34%) 39 (66%) 59

Work on hold 28 (48%) 16 (27%) 15 (25%) 59

Source: Fieldwork 2013

From the table 4.8 17 (29%) of the respondents ranked average Delay in the completion

schedule (time overruns) as an effect of the design change, on the same effect, 42 (71%)

of the respondents ranked it high none of the respondents ranked it low.13 (25%) of the

respondents ranked average increase on project cost (cost overruns) on the same effect,

44 (75%) of the respondents ranked it High none of the respondents ranked it low.32

(54%) of the respondents ranked decrease in productivity as low, 15 (25%) ranked it

average while 12 (12%) of the respondents ranked it high. 24 (41%) of the respondents

ranked low dispute between the project team members, 26 (44%) ranked it average, while

9 (15%) of the respondents ranked it high.20 (34%) of the respondents ranked average

the demolition and rework, while 39 (66%) of the respondents ranked the same factor as

high. 28 (48%) of the respondent ranked work on hold as low, 16 (27%) of the

respondents ranked work on hold average while the remaining 15 (25%) ranked high the

same factors.

Figure 4.8: Effects of the design changes

Source:Fieldwork 2013

4.3.4 Information on the design changes and control of construction

projects in Kenya

The table 4.9 shows the information on the design changes and control of the

construction projects in Kenya.

Statement Low Average High Total

Design changes affects control of

construction

0 12 (20%) 47 (80%) 59

Proper control of construction projects

reduces the effects of design changes.

0 14 (24%) 45 (76%) 59

The construction firms in Kenya have

proper control of the construction projects

15(25%) 32 (55%) 12 (20%) 59

Source: Fieldwork 2013

The table shows that 12 (20%) of the respondents agree on an average that Design

changes affects control of construction, on the same 47 (80%) ranked the statement

high.14 (24%) of the respondents agreed on an average with the statement that proper

control of construction projects reduce the effects of design change, while 45 (76%) of

the respondents ranked the same statement high. 32 (55%) of the respondents agreed on

an average that the construction firms in Kenya have proper control of the construction

project, 15 (25%) ranked it low while 20 (34%) of the respondents ranked high the same

statement.

4.3.5 Information on the level at which the effects of the design changes

affect the control of construction project

The table 4.10 below shows the finding on the level at which the effects of the design

changes affects the control of construction project

Table 4.10 Effects of design change

Very little

extent

Low

extent

Neutral High

extents

Very high

extent

% interval (0-25) (26-49) 50 (51-75) (76-100)

Positively 46 (78%) 13 (22%) 0 0 0

Negatively 13 (22%) 46 (78%)

Source: Fieldwork 2013

From the table 46 (78%) of the respondents were for the reason that design changes affect

positively the control of construction projects to a very little extent of between (0-25)

%,while 13 (22%) with the same stand ranked it low extent of between (26-49) %.13

(22%) of the respondents felt that effects of design changes affects to a high extent (51-

75) % the control of projects in Kenya, while 46 (78%) of the respondents on the same

stand ranked it to very high extent of (76-100) % ,when the explanations of the

respondents were analysed, for the positive effects which were rated either very little

extent or low extent the reason were that it affects to either high extent or to the very high

extent.

4.3.6 Information on the possible methods of improving existing control

techniques on design changes in construction projects in Kenya

The table 4.11 below shows the finding on the control methods used to mitigate the

effects of design changes on the control of construction projects in Kenya.

Methods Least Average Most Total

suitable suitable

Use of WBS 44 (74%) 15 (26%) 0 59

Design freeze 0 (0%) 44 (74%) 15 (26%) 59

Clarity of change order procedure 6 (10%) 40 (68%) 13 (22%) 59

Pricing of indirect effects 6 (10%) 43 (73%) 10 (17%) 59

Review of contracts Documents 3 (5%) 8 (14%) 48 (81%) 59

Use of project checklists on every

milestone

1 (3%) 9 (15%) 49 (82%) 59

Source: Fieldwork 2013

From the table 44 (74%) of the respondents were for the opinion that use of WBS was

least suitable, while 15 (26%) of the respondents ranked it average.44 (74%) of the

respondents ranked the use of Design freeze as average while the remaining 15 (26%)

ranked it most suitable.6(10%) of the respondents ranked the use of clarity of change

order procedure as least suitable while 40 (68%) of them ranked it average with the

remaining 13 (22%) ranking it as most suitable.6 (10%) of the respondents ranked the use

of pricing of indirect effects as least suitable while 43(73%) of them ranked it at an

average and the remaining 10 (17%) ranked it as most suitable.3 (5%) of the respondents

ranked the review of Documents as least suitable,8 (14%) ranked it on average while 48

(81%) of the rest ranked it most suitable. Finally on the use of project checklists on every

milestone 1 (3%) of the respondents said that it was least suitable, 9 (15%) ranked it on

an average while 49 (82%) ranked it most suitable. When the respondents were asked to

specify others none of the respondent gave his or her opinion most likely that the

information provided had captured all the necessary contents.

Figure 4.9 Methods of control

Source: Fieldwork 2013

4.4 CHALLENGES

Every journey has its challenges, this research project was not an exemption to this, and

the following are some of the challenges encountered by the researcher in carrying the

study.

Since the researcher was not present during the filling of the questionnaires, personal

guidance could not be provided to the respondents on how to tackle some of the questions

addressed to them. This led to some respondents addressing different issues in ambiguous

and sometimes contradictory ways. This was noticed to have been especially the case

with the open-ended questions.

There were also cases encountered where the respondents had never heard about some

terms in the questionnaire but could not admit ignorance, design freeze is a good

example. They, therefore, went ahead to fill the questionnaires giving vague and

sometimes contradictory responses. The researcher pre-empted this problem in the design

of the questionnaires and attempted to alleviate it by giving definitions of the technical

terms related some of the words.

In some of the respondents, the questionnaires were given to the junior members of staff

to complete as they were deemed by their bosses to be ‘less busy’. Some of these junior

members of staff were still learning the strings of the job. Their ability to identify

concrete effects of design changes on the control of construction projects in their projects

was, therefore, not expected to be as incisive as that of a more experienced member of

staff.

Other minor problem encountered during the study was non-responsive of some

respondents. 6 respondents did not respond to the questionnaire and due to time

constraints, the researcher could not keep following up on the respondents.

CHAPTER FIVE

DISCUSSION OF FINDINGS, CONCLUSIONS AND

RECOMMENDATIONS

5.0 INTRODUCTION

This chapter presents discussion of the findings of the study, the conclusions made from

the findings, recommendations and suggestions for further studies.

5.1 SUMMARY OF THE FINDINGS

The findings showed that projects involved have experienced changes in the initial

design, from the findings 57 (97%) of the respondents indicates that projects that they

have been involved in have experienced changes in the initial design. It can therefore be

deduced that most projects which have been started in Kenya especially in Nairobi have

experienced changes in the initial stage. From the findings only 2 (3%) of the respondents

have not experienced changes in the initial design in the projects that they have been

involved in. This affirms the fact that design changes are inevitable in construction

projects as discussed in the literature review.

5.1.1 Objective 1: Causes of Design changes.

These changes have been caused by the following factors: causes initiated by the user

s/clients/owners, those initiated by the Architect/consultant, those initiated by the

contractor, those initiated by lack of coordination in the project and finally those

originated from the differing site conditions.

The findings indicate that a number of factors have been responsible for the change in the

initial design these factors vary in the level on which they affect the design change. From

the findings 24 (41%) slightly agree that causes on the changes of design are initiated by

the users/clients/owners while 35 (59%) on the same strongly agree that the causes of the

design change are initiated by the users/clients.36 (61%) of the respondents slightly agree

that causes of design change are initiated by the Architect/consultants, while 23(39%) of

the respondents strongly agree that changes in the initial design are initiated by the

architect/consultants. Other causes of the changes in the design are as a result of initiation

by the contractor, lack of coordination in the project by the project team managers,

Differing site conditions and new government regulations which impose change in the

design of the initial construction design. It can therefore be deduced that most of the

project in Kenya more considerably in Nairobi where the study was carried experience

changes in the design of the construction projects and these changes are as a result of a

number of factors which vary from one project to another.

5.1.2 Objective 2: Effects of design changes on the control of construction

projects

The findings also indicates that the effects of design changes in the construction projects

in Kenya vary as reported by the respondents, these factors are Delay in the completion

schedule (time overruns), increased in project cost (cost overruns), Decreased in

productivity, Dispute between the project team members, Demolition and rework and

work on hold these factors vary from one project to another due to other factors that are

in control.

Findings indicate that design changes and control of construction projects in Kenya have

some correlations; respondents were able to indicate that design changes affect control of

the construction and proper control of the construction projects are also affected by the

design changes in the projects.17 (32%) rates average the effect of design change on

control of the construction while 40 (68%) rates on the same high.

Findings indicates that effects of the design changes affect the control of the construction

projects but these varies from one level to another, these effects can be rated both

negative and positive. 46 (78%) of the respondents were for the reason that the design

changes affect positively the control of the construction projects to a very little extent of

between (0-25) % while the 78% respondents also agreed that design changes negatively

affect the control of the construction projects to a very high extent of between (75-100)%

5.1.3 Objective 3: Project control tools that can be used to mitigate any

effect of design changes

The findings indicate there are possible methods of improving existing control techniques

on design changes in the construction projects in Kenya. These methods include the use

of WBS, Design freeze, clarity of change order procedure, pricing of indirect effects,

review of contract documents and use of project checklist on every milestone. The

adoption of the method varies according to the suitability of the implementation of the

methods.

From the findings, Review of contract documents and the use of project checklist at every

milestone rate highly as the most suitable tools at 81% and 82% respectively. Most of the

respondents commented that the two are practicable and good base to make sure

everything is in order before the construction starts, or the next stage after the milestone

continues. Design freeze (74%), Clarity of change order procedure (68%) and pricing of

indirect effects (73%) were rated as average in terms of their suitability as control tools to

mitigate the effects of design changes. In some interviews with the respondents, design

freeze was rated as an essential tool but only if done with some room to allow only

essential design changes. The use of WBS was rated as the least suitable tool at 74%.

5.2 CONCLUSIONS

The Causes and effects of design changes on the control of construction projects are

complex and influenced by numerous interrelated factors. The risks and uncertainty

associated with project changes make predictions and planning for design changes a

difficult task. Based on the field survey conducted and the results of the finding

presented, the following can be concluded.

1) The information collected indicates that the contractors involved in large building

construction are large in size and most of them reported over 10 years of

experience. Most changes in large building projects are architectural in nature.

The cost overrun due to design changes is shown to be high by 78% of the

respondents. This value agrees with values indicated by some studies as discussed

in literature review. Similarly, the schedule/time overrun is shown to be high by

71% of the respondents. This extension of the schedule is close to values reported

in other studies. Hence, the effects of design changes on cost and schedule are

comparable to other sectors or locations.

2) The owner is the main source of changes in large building projects. Change of

plans by owner is part of the main cause of changes. There are three possible

explanations to this. First, the owner was not involved in the design development.

Second, the owner did not understand or visualize the design. The designer may

not have made the design clear or the owner just lack the ability to read the

drawings. Third, it is merely a change of mind while not appreciating the negative

impacts of changes. In some interviews with the respondents, it emerged that

changes can be made by owner due to financial problems facing the owner.

3) Consultants are a major contributor to changes by generating conflicting design

documents or through change in design after award. 71% of the respondents

slightly agreed that lack of coordination between the project team members can

cause design changes. A good example in an interview with the respondents was a

Structural drawing indicating 100mm thick concrete floor slab while in the

Architectural drawing and BoQ, the same is described as 150mm thick.

4) Noticeably, New government regulations rated low which might be particular to

the environment in Kenya:

5) Increase in project cost and duration are the two main effects being noted for

design changes, rated highly at 75% and 71% respectively. Decrease in

productivity, work on hold and disputes for project team members scored lower

and are less prevalent. The degradation of productivity is considered a major

concern here. This might be explained by good relationship that the project team

members build in the construction process, they all want the best foe each other

for the successful execution of the project. This was however noted to be unique

in private contracts which formed the bulk of the approved developments by

NCC.

6) Review of contract documents for grey areas (81%) and use of a checklist after

every milestone (82%) emerged as the most suitable control tools to be used to

mitigate the effects of design changes. Freeze of design and use of WBS were

discussed as good tools theoretically but very difficult to implement practically,

Design freeze in particular is a good tool to prevent design changes but it’s very

difficult to prevent since design changes are mostly inevitable.

7) Finally, the research showed that if proper control tools are implemented, the

effects of design changes can be mitigated, 76% of the respondents highly agreed

that proper control of construction projects can reduce the effects of design

changes.

5.3 HYPOTHESIS TESTING

The null hypothesis set out at the beginning of this research stated that:

H0 - Design changes do not affect the control of construction projects in Kenya.

The alternative hypothesis was:

HA - Design changes affect the control of construction projects in Kenya.

From the findings of the study, the null hypothesis has been rejected and the alternative

hypothesis accepted.

The study has shown that all the construction projects that responded to the

questionnaires have experienced the effects of design changes which have affected the

control of construction projects in Kenya; they are all affected from a varying degree

from previous project experiences.

5.4 RECOMMENDATIONS

Based on the findings of this research discussed in chapter four with main conclusion

listed above and the referring to findings of previous studies discussed in the literature

review, the following recommendation are made:

1) As concluded earlier, the research indicates that owner/client/developers are the

major source of change orders in large building construction. As gathered from

many field interviews, the owner normally lacks the ability to read design

documents prepared by the design team. Many interviews suggested that owners,

in many instances, get surprised that what is being constructed is not what they

have anticipated or envisioned. Owners of large building projects are usually

businessmen who have a good level of education and with extra effort and visual

aids they should be able to visualize the design. As most changes are

architectural, a three-dimension model is very helpful in this regard and should be

used to help owners and other project team members, see their project before

construction starts. This extra effort in understanding the design would minimize

the changes made by the owner.

2) It is recommended that owners make adequate financial planning during planning

stage to avoid changing plans later or during construction. Cost planning,

estimation and control should be continuous, and thus the quantity surveyor

should be consulted on the cost implication of any design change before it is

implemented.

3) It is worth noting that owners of large construction projects are not repetitive

owners of such projects, and their opinion will be based mostly on one project.

Another justified recommendation for those owners is to get a project

management consultant firm to supervise both the design and construction

activities to ensure that the owners’ needs and expectations are met by the design.

The practice of appointing PMC is rarely adopted currently in Kenya especially in

Nairobi the target area of study.

4) The research finding showed that freezing of design is the least used control tool

against change orders. Owners should consider using this control more often to

avoid the problem of creeping scope where the control over scope is lost.

5) The utilization of review of contract documents as a control tool for grey areas

should be improved and encouraged. As explained in the literature review this

could be a source of many changes and claims during construction. Contractors

should expend more effort prior to contract award to review contract document

for both legal and contractual conditions as well as technical details to spot

unclear areas where conflict over its interpretation may arise. These matters

should be closed and resolved prior to the start of construction.

6) Contractors should consider using a Work Breakdown Structure or other tracking

system more often than is used now. Many contractors indicate they are not using

any type of structuring system for their construction activities and this may lead to

an inability to trace the effects of change orders on the rest of the project.

5.5 SUGGESTIONS FOR FURTHER STUDIES

The following are areas of related interest that can be explored in light of information

provided in this study.

1) The study was based on projects that are approved by the NCC; some projects do

not require this approval e.g. government initiated projects through the ministry of

public works. A study on these projects should be done to see if the effects are the

same for public projects.

2) Since this study address the subject for building project, it would be interesting to

study the subject of design changes in the civil construction works and compare

the results.

3) The study addressed the effects of design changes on the control of construction

projects, a study on the effects of design changes on specific project parameters

e.g. Project schedule, Project Scope and Project cost would add more value to this

field of study.

REFERENCES

Alaa Zeitoun and Garold Oberlender: Early Warning Signs of Project Changes,

Oklahoma State University/CII Source Document No.91, April 1993.

Alarcon and Mardones; Improving the design-construction interface, Proceedings IGLC,

1995

Alfred L. Dellon: The Role of the Cost Engineer and the Change Order Process. CII

Publication 2-3: Productivity Measurement, an Introduction, October 1990.

CII Publication 5-1: Impact of Various Construction Contract Types and Clauses on

Project Performance. The University of Texas at Austin, July 1986.

Construction Industry Institute (CII) Publication 6-10: The Impact of Changes on

Construction Cost and Schedule. The University of Texas at Austin, April 1990.

Dennis Lock: Project Management, fifth edition, The Macmillan Press Limited, London,

1992.

Edward D. Leidholt: An Analysis of Navy Construction Contract Change Order Audits.

M.S. Thesis submitted to the Faculty of Naval Postgraduate School, Monterey,

California. December 1977.

Edward R. Fisk: Construction Project Administration, third edition. John Wiley & Sons

Inc., New York, 1988.

H. Randolph Thomas and Carmen L. Napolitan: The Effects of Changes on Labor

Productivity: Why and How Much, CII Source Document No 99, The Pennsylvania State

University, August 1994.

J.E Dickman and M.P Kim: SUPER CHANGE: Expert System for Analysis of Change

Claims. Journal of construction engineering and management, Vol. 118, No. 2,

September 1995.

James L. Burati Jr., Jodi j. Farrington, and William B. Ledbetter: Causes of Quality

Deviations in Design and Construction; Journal of construction engineering and

management, Vol. 118, No.1, March 1992.

Kelvin Yu: Project Control: cost/schedule/progress management. Cost Engineering

(ACO) Vol. 38 April 1996.

Kevin P. Grant: An Analysis of Factors Affecting the use of Change Orders and

Supplement Agreements. M.S. Thesis submitted to the Faculty of air Force Institute of

Technology, Ohio, and November 1983

Krone, Stephen Jeffrey: Decreasing The impact of Changes ( Ripple Effect , Scope

Changes , Change orders ) , Dissertation Abstract , The George Washington

University , 1991.

Kuprenas J. Algimantas: Use of Influence Diagrams to Asses the Cost and Schedule

Impact of Construction Changes, PhD Dissertation, University of California, Berkeley,

1998.

Project Management Institute; A Guide to the Project Management Body of

Knowledge, PMI Headquarter Publishing Division, N. Carolina,1996.

R. Cooper and C.W. Emory: Business Research Methods, 5th edition, Irwin Inc.

Chicago, 1995.

Robert L.K Tigon: Effective control for Large Scale Construction Projects. Project

Management Journal, Vol.21, March 1990.

Rowland Henry: The Causes and Effects of Change Orders on the Construction

Process. M. S.Thesis submitted to the Faculty of the Georgia Institute of Technology.

November 1981.

Stephen J. Krone: Modeling Construction Change Order Management. Project

Management Journal, Vol.23, September 1992.

The joint building council: Agreement and conditions of contract for building works.

April 1999 edition,

The Laws of Kenya: The architect and quantity surveyors Act, cap 525 laws of Kenya,

Revised edition of 2010

Weston Hester, John A. Kuprenas, T. C. Chang: Construction Changes and Change

Orders: Their Magnitude and Impact, The University of California- Berkeley/ CII

Source Document No.66, April 1991.

APPENDIX I: QUESTIONNAIRE

I am carrying out a study on the effects of design changes on the control of construction projects

in Kenya, a case study of Nairobi. Your sincere assistance will help establish extent of the effects

and fulfill the objectives of this study. Information given will be used only for the purpose of this

research and will be accorded utmost confidentiality.

Please fill in the questionnaire as diligently as you can. Tick in the appropriate box where the

question requires you to do so, where the space is provided, and Please fill in your answer.

PART A

1. What is your profession/Line of business?

Architect Quantity surveyor Engineer

Developer/Client Project Manager Contractor

Others (specify)

……………………………………………………………………………

2. For how long have you been in the profession or line of business?

Less than 5 years 5-10 years over 10 years

3. Kindly indicate your position in the organization.

Director/Principal partner/Owner

Associate partner

Senior staff

Employee

Other (specify) ……………………………………………………….

4. Which professional association do you belong to?

AAK IQSK ICPMK IEK

BORAQS KFMB None

Others (Specify) …………………………………………………………………….

PART B

5. Have any of the projects you were involved in experienced some changes in the initial

design?

YES NO

6. If yes, in a scale of 1-5, kindly rank the following as part of the cause.

Causes of design changes

Str

ongl

yD

isag

ree

Sli

ghtl

yD

isag

ree

Neu

tral

Sli

ghtl

yA

gree

Str

ongl

yA

gree

1 2 3 4 5

Causes initiated by the users/client/OwnersArchitect/consultant Originated

Contractor originated

Lack of coordination in the project teammembers.

Differing site conditions

New government regulation and policy

Others (Specify)

………………………………………………………………………………………….

………………………………………………………………………………………….

7. The following statements relate to the effects of design changes in construction projects

in Kenya. Rate them as per the given Likert scale

Effects of the design changes Low Average High

1 2 3

Delay in the completion schedule (time overruns)

Increase in project cost (cost overruns)

Decrease in productivity

Dispute between the project team members.

Demolition and rework

Work on hold

Others (Specify)

…………………………………………………………………………………………

…………………………………………………………………………………………

8. The following statements relate to design changes and control of construction projects in

Kenya. Rate them as per the given Likert scale.

Statement Low Average High

1 2 3

Design changes affects the control of construction

projects

Proper control of construction projects reduces

the effects of design changes

The construction firms in Kenya have proper

control of construction projects

9. To what extent do you feel the effects of design changes affect the control of construction

projects in Kenya

Explain Briefly

………………………………………………………………………………………………………

………………………………………………………………………………………………………

………………………………………………………………………………

Ver

y

Lit

tle

Ext

ent

Low

Ext

ent

Neu

tral

Hig

h

Ext

ent

Ver

y

Hig

h

Ext

ent

% interval (0–25) (26-49) 50 (51-75) (76-100)

Positively

Negatively

10. The following statements relate to possible methods of improving existing control

techniques on design changes in construction projects in Kenya. Rate them on their

suitability to control construction projects.

Statement Least

Suitable

Average Most

suitable

1 2 3

Use of WBS

Design freeze

Clarity of change order procedure

Pricing of indirect effects

Review of contract Documents

Use of project checklist on every milestone.

Others (Specify)

…………………………………………………………………………………………..

…………………………………………………………………………………………..

THANK YOU FOR YOUR TIME AND COOPERATION

APPENDIX II: LETTER OF INTRODUCTION

Ahmed Albashir Ibrahim,

B66/0345/2009,

Department of Real Estate and Construction management,

School of the Built Environment,

University of Nairobi,

P.O Box 30197-00100,

Nairobi.

28th March, 2013

Dear Sir/Madam,

I am a fourth year Bachelor of Quantity Surveying Student conducting a study titled ‘A STUDY

ON THE EFFECTS OF DESIGN CHANGES ON THE CONTROL OF

CONSTRUCTION PROJECTS IN KENYA, CASE STUDY OF NAIROBI COUNTY’ in

partial fulfillment of my undergraduate degree in Quantity surveying.

Kindly assist me in my endeavor by filling in the questionnaire attached. All the information

you provide will be treated as confidential and will be solely for purposes of this research

project.

Your assistance is highly appreciated.

Yours Sincerely,

Ahmed Albashir Ibrahim

Phone; 0722 433 037

Email; Albashirahmedi@gmail.com

Researcher.

APPENDIX III: LETTER FROM THE DEPARTMENT.