**Notation**

**c**_{e}(z) _{ }**= **Exposure factor

**I**_{v}(z) _{ }**= **Turbulence intensity

**v**_{b }**= **Basic wind velocity

**v**_{m}(z)_{ }**= **The mean wind velocity

**q**_{b }**= **Basic velocity pressure

**q**_{p}(z)_{ }**= **Peak velocity pressure

**ρ**_{ }**= **Air density

The peak velocity pressure *q*_{p}(z) at height z, is calculated using equation below.

The National Annex may give rules for the determination of *q*_{p}(z).

Air density, *ρ *may be given in the National Annex. The recommended value is 1,25 kg/m^{3}.

Exposure factor *c*_{e}(z) is defined equation given below.

Basic velocity pressure *q*_{b} is defined equation below.

For *c*_{o} =1,0 and *k*_{I} =1.0 illustrations of exposure factor *c*_{e}(z) is defined in EN 1991-1-4 Figure 4.2.