Özet:
One of the most common problems in the construction project is delays. Delay is refered as an act or event that extends the time required to perform the tasks under a contract. Projects can be delayed due to number of reasons that may be due to the owner, the contractor, the consultants’ acts, severe weather conditions or any other unexpected conditions. They may occur early or later in the project development, alone, or with other delays. Delays can be minimized only when their causes are identified. The objective of this study is to identify the major causes of delays, their effects on construction projects in Turkey. This study was carried out based on literature review and a questionnaire survey. A total of fifty-one factors and nine groups that contributed to the causes of delay, the six factors that effects delays were identified based on both literature review and construction conditions in Turkey. The questionnaire survey was distributed to the targeted respondents in Turkish construction industry. The objectives of the study have been successfully achieved. The ten top-ranked factors accorded by the construction participants; suspension of the project by owner, delays in contractor’s progress payment by owner, unrealistic project duration, slowness of the owner decision making process, inadequate early planning of the project, financing by contractor during construction, shortage of labor, slow delivery of materials, obtaining permits from municipality and design changes by owner or his agent during construction. Labor related delays were ranked the most significant group that causes delays, followed by finance related delays, material-related delays, changes/revision related delays, and contractual related delays. Time and cost overrun were the common effects of delays in construction projects in Turkey.