In order to determine the height of the building, the base of the building must be determined according to the definitions given in TBDY 2018 3.3.1. In buildings with basements that meet both conditions given in TBDY 2018 3.3.1, the building floor is defined at the floor level above the basement walls.
(a) Rigid basement shearwalls surround the building from all sides or at least three sides;
(b) In the dominant vibration mode in the direction of each of the perpendicular building axes, ratio of the natural vibration period determined for whole building, including the basement floors, to the natural vibration period determined in the same direction, without taking into consideration all the basement masses, including the ground floor slab in the same structural system, is less than 1.1 (Tp,all ≤1.1 Tp,top).
Item (a) of the above conditions is not met because there is no shearwall in the building.
For condition (b), the rigid sign is checked in the Story General Settings. if there is a rigid sign, analysis should be done and the analysis result period control is given in the 'Dynamic Analysis Report'. This sign is not placed because there is no rigid floor in the building.
In the program, it creates a tool for determining the building height with rigid sign in the story general settings. Then, when the conditions (a) and (b) are met, BYS class is determined.
There is no basement in the building. Since height of the building is Hn = 13 m and DTS = 2, it has been determined as BYS=6.