Factors affecting the accuracy of cost estimate during various design stages

Abstract

Purpose The purpose of this paper is to identify factors affecting cost estimate accuracy in each of five design stages preceding building construction: order of magnitude, conceptual/schematic, detailed design, construction document and bid phase. Design/methodology/approach Data were collected using an online survey completed by 138 respondents who work in design consultancy firms in Jordan, including project managers, architects and quantity surveyors (QSs). Survey responses were analyzed using descriptive statistics. Confirmatory interviews and case study comparisons were used to confirm the statistical analysis results. Findings The results of this study indicated that each design stage’s cost estimate was affected by several factors. Two significant factors were common across four of the five design stages: client experience and project team experience. In addition, a high level of agreement was observed among the project managers, architects and QSs regarding the factors affecting cost estimate accuracy. Originality/value Accurately estimating building construction costs during the design process has posed a challenge for designers and their clients in Jordan. Despite the care and effort involved in preparing cost estimates in each of the five design stages, deviations are commonly observed. Because the accuracy of building construction cost estimates directly affect the success or failure of a project, the results of this study can be used to reduce uncertainties in building construction cost estimation and subsequently increase the likelihood of project success

Cost Overrun Gap Analysis in Construction Projects: State -of-the-Art

“…The identified causes for inaccurate cost estimate are shown in Table 7, where the top five causes related to the contractor cost management system are relevant experience of estimating team, accuracy, and reliability of cost information/ the availability of prices for labor and material, availability and quality of historical cost data, availability of productivity standards, time allowed for estimation. [126], [127], [128], [129], [130], [131], [132], [133] 2 Relevant experience of estimating team [126], [134], [135], [127], [136], [137], [138], [128], [129], [139], [140], [139], [141] , [130], [132] , [133] 3 Accuracy of bidding documents provided by client / clear and detail drawings and specification [134], [135], [127], [137], [142], [128], [129], [140], [130], [131], [132] 4 Accuracy and reliability of cost information/ the availability of prices for labor and material [134], [127], [137], [143], [142], [138],…”

“…One of the factors that influence the accuracy of estimates could be the nonavailability of accurate labour productivity data [136], [129], [139]. There is a shortage of availability of productivity data in a formalized database for the construction industry, which also affects the overall labour costs in the estimate, while the labour rates have a vital influence on the accuracy of the estimate [129].…”

Reliability of Cost Data for Detailed Construction Cost Estimating in Egypt

“…Cost estimation applies techniques and techniques to estimate any possible cost, scale, or characteristics based on the information available at that time [23]. The most important factors influencing the accuracy of construction estimating in the detailed estimate process are the quality and reliability of cost information about materials and labor costs [24], [9], [25], [11], [26].…”

Cost Estimation Performance in the Construction Projects: A Systematic Review and Future Directions

“…The factors of cost estimation performance were summarized and clustered into shared dimensions which are shown in Table 3. (2000), Akintoye & Fitzgerald (2000), Al-Harbi et al (1994), Arif et al (2015), Doloi (2011), Enshassi et al (20050, Flyvbjerg et al (2002), Hatamleh et al (2018, Mahamid (2015) External stakeholder influence Akintoye (2000), Akintoye & Fitzgerald (2000), Al-Harbi et al (1994), Arif et al (2015), Chan & Park (2005), Dandan et al (2019), Doloi (2013), Enshassi et al (2005), Flyvbjerg et al (2002, Grau et al (2017), Hatamleh et al (2018, Mahamid (2015) Oberlender & Trost (2001, Sridarran et al (2017) The complexity of the contractual relationship Agyekum et al (2018), Akintoye (2000), Akintoye & Fitzgerald (2000), Al-Harbi et al (1994), Chan & Park (2005), Dulaimi & Shan (2002), Elhag et al (2005), Enshassi et al (2005), Mahamid (2015), Oberlender & Trost (2001) According to the systematic review, the factors were clustered into six main themes: input control, behavior control, output control, project complexity, task characteristic, and technology characteristic. Each of the themes is discussed below for a better understanding of the attribute of the themes.…”