## Question

**In GEN, what is the base height from which the altitude distribution factor is obtained?**

## Answer

**The altitude distribution factor is used to calculate the design velocity pressure and is applied within the GEN programme as shown in the following image.**

[Image] How to calculate the wind load's wind pressure area

This means that when applying an altitude distribution factor at the height of the 6th floor, the altitude distribution factor of the floor level of the 7th floor is applied to A1 (the upper half of the height of the 6th floor), and the altitude distribution factor of the floor level of the 6th floor is applied to A2 (the lower half of the height of the 6th floor).

The text output file (Load > Lateral Loads > Wind Loads > Wind Load Profile...), which summarises the wind load calculation process, shows the value of the ceiling level of the corresponding floor among the two height distribution factors.

[Image] Text Output File