Achieving Design-Stage Elemental Cost Planning Accuracy: Case Study of New Zealand
An aspect of client expenditure management that requires attention is the level of accuracy achievable in design-stage elemental cost planning. This has been a major concern for construction clients and practitioners in New Zealand (NZ). Pre-tender estimating inaccuracies are significantly influenced by the level of risk information available to estimators. Proper cost planning activities should ensure the production of a project’s likely construction costs (initial and final), and subsequent cost control activities should prevent unpleasant consequences of cost overruns, disputes and project abandonment. If risks were properly identified and priced at the design stage, observed variance between design-stage elemental cost plans (ECPs) and final tender sums (FTS) (initial contract sums) could be reduced. This study investigates the variations between design-stage ECPs and FTS of construction projects, with a view to identifying risk factors that are responsible for the observed variance. Data were sourced through interviews, and risk factors were identified by using thematic analysis. Access was obtained to project files from the records of study participants (consultant quantity surveyors), and document analysis was employed in complementing the responses from the interviews. Study findings revealed the discrepancies between ECPs and FTS in the region of -14% and +16%. It is opined in this study that 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. Further, whilst inherent risks in construction project developments are observed globally, these findings have important ramifications for construction projects by expanding existing knowledge on what is needed for reasonable budgetary performance and successful delivery of construction projects. The findings contribute significantly to the study by providing quantitative confirmation to justify the theoretical conclusions generated in the literature from around the world. This therefore adds to and consolidates existing knowledge.
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 Adafin, J., Wilkinson, S., and Rotimi, J.O.B. (2014). “An Exploration of Theoretical Concepts and Methods for Assessing Risk Impacts on the Variability between Design Stage Elemental Cost Plan and Tender Sum”, CIB W107 2014, Lagos, Nigeria, 308 –316.
 Aibinu, A. A., and Pasco, T. (2008). “The accuracy of pre‐tender building cost estimates in Australia”, Construction Management and Economics, 26(12), 1257-1269.
 Akintoye, A. S., and MacLeod, M. J. (1997). "Risk analysis and management in construction." International Journal of Project Management, 15(1), 31-38.
 Ashworth, A. (2004). Cost Studies of Buildings, 4th edn, Pearson Education Ltd, London.
 Ashworth, A. (2008). Pre-contract Studies: Development Economics, Tendering and Estimating, 3rd ed, Blackwell Publishing Limited, UK.
 Ashworth, A., and Hogg, K. (2007). Willis's Practice and Procedure for the Quantity Surveyor, 12th ed, Blackwell Publishing Ltd, Oxford.
 Baloi, D., and Price, A. D. F. (2003). "Modelling global risk factors affecting construction cost performance." International Journal of Project Management, 21(4), 261-269.
 Bello, W. A., and Odusami, K. T. (2008). "The practice of contingency allocation in construction projects in Nigeria." RICS COBRA, RICS, London, 1 - 15.
 Bryde, D. J., and Volm, J. M. (2009). “Perceptions of Owners in German Construction Projects: Congruence with Project Risk Theory”, Construction Management and Economics, 27(11), 1059-1071.
 Chapman, R. J. (2001). "The controlling influences on effective risk identification and assessment for construction design management." International Journal of Project Management, 19(3), 147-160.
 Cheong, P. F. (1991). “Accuracy in Design Stage Cost Estimating”, Unpublished MSc Dissertation, National University of Singapore.
 Choy, W. K., and Sidwell, A. C. (1991). "Sources of Variations in Australian Construction Contracts." Building Economist, 30(3), 25-30.
 Enshassi, A., Mohamed, S., and Abdel-Hadi, M. (2013). "Factors Affecting the Accuracy of Pre-Tender Cost Estimates in the Gaza Strip. " Construction in Developing Countres, 18(1), 73-94.
 Enshassi, A., Mohammed, S. A. M., and Madi, I. (2005). "Factors affecting accuracy of cost estimation of building contracts in the Gaza strip." Journal of Financial Management of Property and Construction, 10(2), 115 - 124.
 Farinloye, O. O., Salako, O. A., and Mafimidiwo, B. A. (2009). "Construction professional's perception of risk impact on cost of building projects in Nigeria construction industry." RICS COBRA, RICS, London, 227 - 243.
 Gibson, W. J., and Brown, A. (2009). Working with Qualitative Data, SAGE Publications Ltd, London.
 Jin, X. H., Doloi, H., and Gao, S. Y. (2007). “Relationship‐based determinants of building project performance in China.” Construction Management and Economics, 25(3), 297-304.
 Kirkham, R. (2007). “Ferry and Brandon's Cost Planning of Buildings.” 8th Edition, Blackwell Publishing Ltd, Oxfordshire.
 Laryea, S., and Hughes, W. (2006). “The Price of Risk in Construction Projects.” In Proceedings of 22nd Annual ARCOM Conference, Association of Researchers in Construction Management, UK, vol. 2, pp. 553-561.
 Ling, Y. Y., and Boo, J. H. S. (2001). "Improving the accuracy estimates of building of approximate projects." Building Research & Information, 29(4), 312-318.
 Morrison, N. (1984) “The accuracy of quantity surveyors' cost estimating.” Construction Management and Economics, 2(1), 57-75.
 Nworgu, B. G. (2006). Educational Research: Basic Issues and Methodology, 1st Edition, Wisdom Publishers Ltd, Nigeria.
 Odeyinka, H. (2007). “Modelling risk impacts on the budgeted cost of traditionally procured building projects, ARCOM, D. Boyd, ed., ARCOM, UK, 755 - 763.
 Odeyinka, H. A. (2010). “Assessing Risk Impacts on the Budgetary Reliability of Design Stage Elemental Cost Plan”, available at: http://www.docstoc.com/docs/99896893/built_environment (accessed 11 June 2014).
 Odeyinka, H. A., and Yusif, A. (2003). "An Assessment of the Accuracy of Quantity Surveyors' Preliminary Cost Estimates in Nigeria." Construction Engineering, 18(1), 33 - 38.
 Odeyinka, H. A., Oladapo, A. A., and Akindele, O. (2006). “Assessing Risk Impacts on Construction Cost.” In Proceedings of RICS COBRA, RICS, London, UK.
 Odeyinka, H., Kelly, S. and Perera, S. (2009). “An Evaluation of the budgetary reliability of bills of quantities in building procurement.” In Proceedings of RICS COBRA, RICS, UK, pp. 435-446.
 Odusami, K. T., and Onukwube, H. N. (2008). "Factors affecting the accuracy of pre-tender cost estimate in Nigeria." RICS COBRA, RICS, London, 1 - 10.
 Oladokun, M. G., Oladokun, A. A., and Odesola, I. A. (2011). "Accuracy of Pre-Tender Cost Estimates of Consultant Quantity Surveyors in Nigeria." Journal of International Real Estate and Construction Studies, 1(1), 39 - 52.
 Rawlinsons Media Ltd (2011). Rawlinsons New Zealand Construction Handbook, 26th edn, Rawlinsons Media Ltd, Auckland, New Zealand.
 Royal Institution of Chartered Surveyors (2012). RICS New Rules of Measurement 1: Order of Cost Estimating and Cost Planning for Capital Building Works, 2nd Edition, RICS, Coventry, UK.
 Skitmore, R. M., and Picken, D. (2000). "The Accuracy of Pre-Tender Building Price Forecasts: An Analysis of USA Data." Australian Institute of Quantity Surveyors Refereed Journal, 4(1), 33-39.
 Smith, J. and Jaggar, D. (2007). Building Cost Planning for the Design Team, 2nd Edition, Elsevier, Oxford.
 Taylor, S. J., and Bogdan, R. (1984). Introduction to Qualitative Research Methods, Wiley-Interscience, New York, NY.
 Towner, M. and Baccarini, D. (2007). “Risk Pricing in Construction Tenders - How, Who, What.” Construction Economics and Building, 7(2).
 Winch, G. M. (2010). Managing Construction Projects, 2nd edn, Blackwell Publishing, Oxford.
 Zou, P. X. W., Zhang, G., and Wang, J. (2007). "Understanding the key risks in construction projects in China." International Journal of Project Management, 25(6), 601-614.
 Zuo, K. X. (2010). Procurement and Contractual Arrangements for Post-Disaster Reconstruction, Unpublished PhD Thesis, The University of Auckland, New Zealand.