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Eurocode 1 Wind load on building side walls (external and internal pressure coefficients)

Description:
Calculation of wind load action effects on vertical side walls of building. The net effect of external and internal wind pressure for zones A, B, C, D, E on the wall surface are calculated from the corresponding pressure coefficients
According to:
EN 1991-1-4:2005+A1:2010 Section 7.2.2
Applicable for:
Vertical walls of rectangular plan buildings, flat or inclined roof, and height h less than five times the width b perpendicular to the wind direction, consisting of one skin
All Calculations
Input
m/s
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
m
m
m
Local coefficients cpe,1 are intended for design of small elements and fixings with an area per element ≤ 1 m2 (e.g cladding elements, roofing elements). Overall ceofficients cpe,10 may be used for the design of the overall load bearing structure with loaded area ≥ 10 m2.

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.
Minimum value of internal pressure coefficient cpi to be used when unfavorable. For buildings without a dominant face and where it is not possible, or not considered justified, to estimate ratio μ the value cpi = -0.3 may be used. Otherwise more accurate value may be determined in accordance with EN1991-14 §7.2.9. Enter cpi,min = cpi,max= 0 to ignore internal pressure.
Maximum value of internal pressure coefficient cpi to be used when unfavorable. For buildings without a dominant face and where it is not possible, or not considered justified, to estimate ratio μ the value cpi = +0.2 may be used. Otherwise more accurate value may be determined in accordance with EN1991-14 §7.2.9. Enter cpi,min = cpi,max= 0 to ignore internal pressure.