The unit price of building changes to different design of seismic importance factors

The design of a building needs to accommodate the potential for earthquake risk. The function and utilization of buildings are closely related to the risks caused by earthquakes, especially for people using the building. In the design process, load changes due to utilization are accommodated through an index value called seismic importance factors (SIF). The application of the index will directly affect the structural dimensions of a building. Thus, the amount of building unit price (BUP) needed will also vary according to the function of the building. This research was conducted to analyze changes in BUP on some seismic importance factors in a building structure design. Changes in unit prices were explained by applying the price index approach in the form of the building unit price index (BUPI). This study was applied to a six-story building using reinforced concrete structures and following earthquake load conditions in four seismic zones in Aceh Province. The BUPI was analyzed based on comparing a building unit price (BUP) to the reference BUP that was set from the building designed with the lowest SIF index in the initial seismic zone. The analysis results show that the increase in the SIF indices will potentially increase the BUP to 6 % (IDR. 105,061.25) for SIF 1.00 to 1.25, while the increase in costs for SIF 1.25 to 1.50 was 4 % (IDR. 84,507.32). The BUPI values have clearly explained how the building unit price increases following the SIF indexes increase.