Incompatibility between Design and Construction in Building Construction

Abstract

Building construction projects are started with the ambition to transform the customer requirements into best serving products requiring minimum alterations or additions during the course of construction. However, requirements defined during the design phase change during construction phase (Alarcon et at. 1998). These changes cause incompatibilities between the design and construction phases. The most common changes or incompatibilities are made in the architectural details, structural details, materials and quality. The result of these changes is rework (Undurrage 1996), change orders, construction delays, cost over-runs, etc. Situations like these cause reduction in investment and potential growth of the building construction. Keeping in view the importance of the building construction and consequences of incompatibilities as explained above, it was decided to carry out a research in this field to study the causes of incompatibilities and their ranking in the building construction industry of Pakistan. This study included feedback in the form of questionnaire survey from two hundred and eighty one (281) respondents including clients, consultants and contractors connected with building construction constructed using the traditional procurement method, In addition, many of them have past experience of working in other parts of the country. From a detailed study of past literature review of international studies, a list of sixty five (65) causes of incompatibilities were outlined which were further grouped in four (04) categories. After obtaining data from the field survey, reliability test of data was conducted in order to confirm the authenticity of the field data. Next the individual ranking of each cause was ascertained using Relative Importance Index for clients, consultants and contractors. Overall ranking for each category was also calculated. Percentage mutual agreement between the three stake holders was also established in order to know the degree of agreement in their views about the causes of incompatibilities.