A Risk Analysis of Construction Projects Delay Factors in the United Kingdom

Project time overruns is a recurring challenge in the construction industry. This paper mainly identified the causes of construction project delays, analysed the probability and impact of occurrence, and ranked the risk factors. The identified factors are categorised into Client, Consultant, Contractor, and External related factors. To achieve the research objective, the identified delay factors were part of a questionnaire survey; and responses were yielded from building construction experts in the United Kingdom. The relative importance index (RII) method was applied to prioritise the probability and impact of project delay factors and determine the risk level. In the four categories, delay in decision-making and order issuance by the client, variation and changes in design, delay in the approval of drawings, and delay in design preparation and late revision of designs are some of the identified top-ranking risks. In addition, the delay in providing utilities, construction mistakes, defective works and rework, adverse weather conditions, and delays or issues regarding permissions and statutory approvals are among the top-ranking risks. This research is expected to significantly contribute to and improve the understanding and perception of the risks posed by the various delay factors, especially in the building construction industry.