ABSTRACT
This research work deals with the investigation of the reliability or otherwise of the engineer's estimate in selective tendering for building works. The term 'engineer's estimate' as used in this work means the estimated cost of a building normally prepared for the client by his construction cost consultants just before or during tender period,based on the same tender documents given to selected tenderers. In this work, the bills of quantities forms part of the tender documentation. This estimate is also referred to as comparative or pre-tender or QS estimate. The investigation is limited to pre-contract stages of the building process. As a result of this, the investigation dealt mainly with the question of how reliable the engineers estimate is to the client, in terms of getting responsible tenders and awarding the contract within not more than +10 percent difference from the engineers estimated cost. It has been discovered during the investigation that clients rely heavily on the engineers estimate to the extent that for a contractor to win a contract for building works, his tender should not differ by more than +10 percent of the engineers or QS estimate. In addition to this, it has also been discovered that strict reliance on the engineers estimate, especially in cases where the trend of tenders reveal otherwise, might result in unpleasant post contract problems such as escalation of costs and possible delay or abandonment of the project. This is because the engineers estimate is not 100 percent reliable. As such, in cases where majority of tenders received differ very significantly from the engineers estimate, then the accuracy or otherwise of the engineers estimate should be looked into. Recommendations on how to improve the reliability of the engineers estimate are proposed in the conclusions. In general, this work has helped to bring out some problems in tendering as well as preparation of tender documents and pricing. It is hoped that the result of this research will be of immense benefit to the Government, various members of the Construction Industry and the general public.