Small or middle scaled residential projects have a big share in the industry and majority of the fatal accidents usually occur on such work sites. In this study, drawings, technical specifications, bill of quantities of 25 small or middle scaled concrete residential buildings with total areas that vary between 252 and 221.979 m2 in Istanbul were examined. The study aims to give an approach for safety cost estimation for the early stages of construction bidding phase using risk assessment activities and construction project scheduling by focusing on construction activities. Additionally, a cost analysis was performed and the results were compared and Primavera P6 was utilized for scheduling, and risk assessment was conducted using the techniques applicable for construction projects (i.e., L matrix and Fine-Kinney). Finally, activity-based techniques were used for cost estimation. The results of this study reveal that the percentage of occupational health and safety (OHS) cost to the total construction cost is 2.6%. Also, to comply with the current legislation and minimize risks; 0.95 USD per man-hour should be spent according to 2013 rates and OHS cost per unit area was found as approximately 9.37 USD.