Eurocode 1 Wind load on prism elements with rectangular cross-section (force coefficient)

Calculation of wind load action effects on prism elements with rectangular cross-section. The total horizontal wind force is calculated from the force coefficient corresponding to the overall effect of the wind action on the structure
According to:
EN 1991-1-4:2005+A1:2010 Section 7.6
Applicable for:
Structures with rectangular plan, isolated elements with rectangular cross-section
All Calculations
The basic wind velocity is given as vb = vb,0cdircseason where the fundamental value of basic wind velocity vb,0 is defined in EN1991-1-4 §4.2(1)P and its value is provided in the National Annex. The directional and season factors are generally cdir = 1.0 and cseason = 1.0. Values different than 1.0 may be specified in the National Annex for EN1991-1-4 §4.2(2)P
The terrain categories are illustrated in EN1991-1-4 Annex A. The transition zones between terrain categories are specified in EN1991-1-4 §A.2.
Wind terrain category 0 Wind terrain category I Wind terrain category II Wind terrain category III Wind terrain category IV
Illustration of Terrain categories reproduced from EN1991-1-4 Annex A
For cross-sections with sharp corners r=0

Orography factor different than 1.0 may be applicable over isolated hills and escarpments. See EN1991-1-4 §4.3.3 and §A.3 for more details.
Structural factor cscd in accordance with EN1991-1-4 Section 6. A value of cscd = 1.0 is generally conservative for small structures not-susceptible to wind turbulence effects such as buildings with height less than 15 m.