Reference wind speed

Is a reference value that can be picked from the pictures below and which is defined as the average wind speed for 10min at 10 meters above ground and occurs once every 50 years and has a roughness factor z₀=0,05.

Vindzon

A factor that depends on which side of the building's walls is calculated in accordance with the picture below.

Wind zone	Cpe
A	-1,2 (suc)
B	-0,8 (suc)
C	-0,5 (suc)
D	0,8 (pres)
E	-0,7 (suc)

Terrain type

Terrain type		z0	z0
		m	m
0	Sea or coastal area exposed to open sea.	0,003	1
I	Lake or flat and horizontal area with negligible vegetation without obstacles.	0,01	1
II	Area with low vegetation such as grass and occasional obstacles with minimum spacing equal to 20x the height of the barrier (eg trees, buildings).	0,05	2
III	Area covered with vegetation, buildings or single obstacles with maximum mutual distance equal to 20x the height of the obstacle (eg villages, suburbs and forest land).	0,3	5
IV	Area where at least 15% of the area is built and the average height of the buildings is at least 15m.	1,0	10

Density

The density of the air that can be expected under extreme wind conditions in the area in question is usually set to 1,25 kg/m³.

Turbulence factor

A factor that takes into account the turbulence that occurs around the building, usually set to 1.

Topografifaktor

A factor that takes into account the topography of the building is usually set to 1.

Safety factor

A factor that takes into account safety margins in the calculations.

Load factor

A factor which depends on how the load affects the wall usually a variable load ie wind.

Wind load

The dimensioned wind load to which the current wall is exposed.