Abstract
This study investigated the variation caused by building consultants in construction industry of Nigeria. Variation in construction projects are very common and likely to occur from different sources, by various causes, at any stage of a project, and may have considerable negative impacts on items such as costs and schedule delays. This study is aimed to assess the causes of variation on construction project, the factors influencing the occurrence of variation on project and to determine the impacts of variation on project delivery in relation to cost and time. Questionnaire survey was used; out of 80 questionnaires that were sent out 78 questionnaires were retrieved from respondents in the contracting firm, consulting firms and government parastatals in Oyo state. The findings showed that; owner’s financial problem, change in specification by owner, change in scope of the project, care the most important causes of variation. The presence of specialist works, unforeseen conditions, and incompleteness of design are the top factors influencing the occurrence of variation. The most important impacts of variation on project delivery in relation to cost are quality degradation, increase in project cost, delay in completion and logistics delays while the most important impacts of variation on project delivery in relation to time are logistics delays, delay in completion and quality degradation.
CHAPTER ONE
INTRODUCTION
1.1Â BACKGROUND OF THE STUDY
The living standard in Nigeria generated many development opportunities in the manufacturing and building sectors. The satellite towns have accelerated as a result of high population growth. Large and complex projects have been built attracting contractors from all over the world. Most of these contractors appear to lack sufficient understanding of social, cultural and physical environment of Nigeria. This situation coupled with inexperienced consultants has led to inadequate design resulting in many changes to plans, specifications and contract terms. A construction contract is a business that is subject to variability Variation quality or quantity of the works as shown upon the contract drawings and described by or referred to in the contract bills. This includes the addition, omission or substitution of any (minor) work or the alteration of the type or standard of any materials or good to be used in the works and the removal from the site of any work materials or goods executed or brought thereupon by the contractor for the purposes of the works.
Variation as contained in the standard form of building contract in Nigeria (SFBCN) is defined as the modification of design or quantity of work as shown upon the contract drawings and described by or referred to in the contract bills. It includes addition, omission or substitution of any works. Its importance in the preparation of final account is further ascertained by Agbo (1993) who claimed that variations would occur in virtually every contract. Even though it could arise from the client, designers, contractors among other, the condition of the contract only empowers the Architect to issue variation orders, hence the attribution of variation in most cases to the Architect. Under clause 11.2 of the SFBCN, 1990 variations may arise under Circumstances that could not have been reasonably foreseen before signing the contract.
