TS 498 – Turkish Building Wind Load Standard

In Turkey, façade wind pressures are determined with TS 498:2021. The standard specifies formulas, coefficients and safety factors depending on height, orientation and panel type. Key points are summarised below.

1. Basic Wind Pressure Formula

w = C_p × q

where q is the velocity pressure (kN/m²) and C_p the aerodynamic coefficient (positive/negative).

2. Velocity Pressure (q)

q = v² / 1600 (TS 498 §14.3)

v = basic wind speed (m/s). Alternatively, design values may be taken directly from Table 4 of the standard.

3. Typical C_p Coefficients

Windward flat façade: C_p ≈ +0.80 (pressure) / –0.80 (suction)
Side façade (parallel flow): C_p ≈ –0.50
Corner zones / overhangs: safety factors may be increased.

4. Increase for Isolated Elements

For individual panels or frames the velocity pressure is increased by 25 %:

q_design = 1.25 × q

5. Worked Example

Height band: 21–100 m
v = 42 m/s → q = 1.10 kN/m² (tabulated)
Isolated panel: q = 1.10 × 1.25 = 1.375 kN/m²
C_p = 0.80 (windward pressure)
w = 0.80 × 1.375 ≈ 1.10 kN/m²

Beus Facade engineers combine TS 498 with TS EN 1991-1-4 to deliver façade designs compliant with both national and Eurocode requirements.