In this section, the maximum peak velocity pressure qp(z) is calculated in accordance with EN-1991-1-4 2005. Depending on the National Annex the equations and methods for calculating the peak velocity are different. Considerable effort has been put into the curation of the ESICS wind calculator to accurately calculate the qp(z) based on the right National Annex. Therefore for simplicity, only the UK NA method will be discussed in this section to familiarize the user with the factors and equations used. Figures 10 and 11 are flowcharts for obtaining peak velocity for sites in Country and Town terrain respectively in accordance with BS EN 1991-1-4:2005.

Figure 10. Flowchart for Obtaining Peack Velocity Pressure for sites in country.

Figure 11. Flowchart for Obtaining Peak Velocity Pressure for Sites in Town Terrain.

As seen in the flow charts above obtaining the Peak velocity pressure is a complex procedure. ESICS applies this method shown in Figures 10 and 11 to calculate the peak wind velocity in twelve directions. Once these values are obtained the maximum value between the twelve is chosen as the maximum peak velocity pressure.