ABSTRACT
Identification and assessment of factors influencing construction tender sum helps in building a more reliable cost models that help Quantity surveyors come up with a more accurate cost estimates. Several researches have been carried out in the UK and other developed countries with results varying on one hand based on the questions asked and on the other hand the nature of the economy. This research was undertaken to assess the factors that affect the tender sum in Nigeria. Factors were identified to be peculiar to Nigeria. The research was a two phase research. The first was the literature review. In this phase, a total of 73 factors affecting tender sums were identified and further grouped into six categories. There were fFactors were identified to to be peculiar to Nigeria being a developing economy. The second phase was a Questionnaire survey.Questionnaires were administered to Qquantity Ssurveyors in the FCT, Kaduna and Plateau States,Nigeria and the data was analysed. Priority ranking of cost influencing factors was carried out using their significance index. The average indices for the groups range from 75.2 to 63.6%.These factors were subjected to factor analysisso as to bring out the actual redundant factors. They include of registration with the client, working relationship with the client, project finance methods etc. the most critical factors include site conditions, tender selection methods, plant cost, labour cost etc. findings of the research indicates that Quantity Surveyors perceive that tender sums are more influenced by project characteristics. Some factors that were considered to be critical in previous research were redundant in this research. This concludes that the location and economic situation of a location influence the factors that determine tender sum in that location. It was recommended that determinants of tender sum should be examined so as to know the degree to which it affects the Comparison of the outcome of this research and previous ones were presented.tender sum. This will help in proper tender evaluation and thus the overall success of the project.