In the construction of vertical buildings, the implementation method used affects the productivity of construction. The development of construction system innovation in Indonesia which continues to grow has led to a new system, one of which is the precast system. Precast systems have been proven to be able to increase productivity in terms of construction time and costs, as well as the value of waste costs, which results in little from conventional methods. The main objective of this study was to compare the efficiency of the method of implementing floor slabs in the field by comparing the variables of field implementation, costs, time, quality control, and material waste costs of the conventional and precast half – slab methods. The analysis was carried out using the unit price is based on the Jakarta Worker’s Wage Unit Price 40 year XXVII – 2021 edition. The index coefficient (conventional) refers to the Minister for Public Works and Human Settlements Regulation No. 1 of 2022, and the index coefficient (precast half slab) refers to SNI 7832:2012. Scheduling was performed using Microsoft Projects. The results show that the precast half – slab method is more efficient than the conventional method.