Risk impact assessments in project budget development: quantity surveyors' perspectives

One aspect of construction project budgeting requiring attention is the inaccuracy of early estimates during design development. Accuracy of estimates is important to project owners and their financiers. However, inconsistent risk information makes this difficult to achieve. Proper risk analysis could offer a partial solution by reducing the variance between design-stage elemental cost plans (ECPs) and final tender sums (FTS) of construction projects. This study first identifies risk factors that influence variability between ECPs and FTS. It further evaluates the identified risk factors through risk measurement to determine the most significant during design development. Data for the study were sourced from 62 practicing quantity surveyors (QS) through an online questionnaire survey. Survey responses were analysed by using descriptive statistics, risk mean analysis (RMA), degree of risk measure and Spearman's correlation. The Statistical Package for the Social Sciences (SPSS) software facilitated the analysis, and top ten risk factors were found important for practicing quantity surveyors in New Zealand (NZ). The identified risk factors were responsible for the variability observed. The values obtained from the analysis would enable greater accuracy in the forecast of FTS by quantity surveyors. As a main contribution, the study creates awareness of the risk factors that should be given considerable attention by consultants at project outset, to guard against wide variation between the design-stage ECPs and FTS. This knowledge could assist quantity surveyors to pro-actively manage their client's fund. In addition, these findings can assist in the development of a predictive model that construction industry practitioners in NZ could use for reliable estimation of FTS from the design-stage ECP.