PurposeProjects often face delays and unnecessary use of time due to various factors and reasons, and hence suffer from unfavourable consequences. The purpose of this paper is to identify the universal delay factors from an intensive literature review, complemented by delay factors in major Norwegian construction projects based on empirical data.Design/methodology/approachThe study in which this paper is based includes an intensive literature review, and semi-quantitative open survey questionnaires. This paper addresses frequency and type of delay factors in construction projects, in Norway based on the survey, and worldwide based on the previous studies.FindingsFrom the study, the causes of delays facing the Norwegian construction industry are: poor planning and scheduling; slow/poor decision-making process; internal administrative procedures and bureaucracy within project organisations; resources shortage (human resources, machinery, equipment); poor communication and coordination between parties; slow quality inspection process of the completed work; design changes during construction/change orders; sponsor/owner/client lack of commitment and/or clear demands (goals and objectives); late/slow/incomplete/improper design; office issues; and users’ issues. And the top 10 universal delay factors are: design changes during construction/change orders; delays in payment of contractor(s); poor planning and scheduling; poor site management and supervision; incomplete or improper design; inadequate contractor experience/building methods and approaches; contractor’s financial difficulties; sponsor/owner/client’s financial difficulties; resources shortage (human resources, machinery, equipment); and poor labour productivity and shortage of skills.Research limitations/implicationsWhen it comes to the identification of delay factors in major Norwegian projects, the research is based on a sample of 202 respondents from an open survey questionnaire. It should be noted that analysing a large population of respondents that have been asked open questions can be challenging due to the vague findings it might lead to. Also, when it comes to the identification of the universal delay factors, there were different methods used by different authors, within different context. Similar future studies in Norway based on qualitative and quantitative methods will give better verification for the findings.Practical implicationsThis paper has documented the critical delay factors/causes in Norway. The results of this study will help project managers, in Norway and elsewhere, to be aware and know about the potential causes of delay in their construction projects, which will help to identify the possible risks in the early phases of the project. Another practical implication is to make project managers and policy makers conscious that delays are quite universal, making it necessary to identify them as a first step.Social implicationsThe identification of delays factors and causes can permit projects to implement mitigation actions to avoid delays, thus allowing delivering schools, hospitals and other necessary infrastructure on schedule or ahead of schedule to society.Originality/valueThis paper highlights most (almost all) of the studies in the literature, including to the study done in Norway, concerning the delay factors in construction projects and large construction projects in general. This wide review of relevant literature will save time other academicians from having to conduct similar studies. This study will assist both academic and professional experts providing more insight about the delay causes in large-scale construction projects.