AN INVESTIGATION INTO THE DIRECT AND INDIRECT COST OF REWORK IN BUILDING CONSTRUCTION-A CASE STUDY OF A RESIDENTIAL BUILDING PROJECT IN NAIROBI COUNTY

ABSTRACT The study sought to investigate the direct and indirect costs of rework in building construction projects. It also aimed at investigating the most frequent rework activities performed in building projects and the share of the costs among the major project stakeholders. It finally provides propositions for mitigating rework activities and their equivalent costs.
The study involved a wide review of literature as a source of knowledge on rework in construction. The study target was building construction projects in Nairobi County due to the increasing number of building construction in the area. A case study of a residential building project was purposively selected in order to deeply analyze the concept of rework and the related costs. In addition, the study used questionnaires administered to the main contractors of other ten purposively selected projects as a basis of comparison on rework activities and respective costs.
The study focused on rework categories which include: reinforced concrete works, block works, plaster works, painting, ceiling works, flooring and cladding, doors and windows, electrical works, plumbing works, joinery work and external building works. These rework categories were chosen according to the major activities that take place in construction of building projects.
The direct cost of rework was found to be 2.35% while the indirect cost was 1.36% of the total project cost. This is a total of 3.71% on the project cost. The study also indicated that the client has the largest share of rework cost of about 60% followed by the contractor with 30%.A delay of 5.29% on project delivery was also established due to reworks.
The study findings indicated that rework activities are similar in every building project but only differ in their magnitude something which could be attributed by difference in project size, conditions of carrying out the works and project complexities. The most frequent rework activities were recorded under the painting rework category whereby different areas required repainting or additional coats of paint due to concrete stains, changes, and dissatisfaction of the customer. Only few reworks are done under the external rework