Updated: 07.11.2026
The Terrain category describes how rough the surroundings of a building are. Over open sea or flat land the wind blows unhindered; in towns and forests buildings and trees slow it down near the ground.
What is the effect?
- Smooth terrain (coast, open field): higher wind load even at low height
- Rough terrain (suburb, city): lower wind load near the ground
- With increasing height the differences even out – tall buildings are more exposed everywhere
Alongside the Wind zone and the building height, the terrain category is a parameter under DIN EN 1991-1-4. The calculation is done by the structural engineer.
In practice
If a building is exposed, on the coast or tall, plan +50 % Reserve and a wind sensor for the window actuator.
Read more
Tools: Calculate force and stroke with the Window actuator calculator, find the right model in a few questions with the actuator finder.
Not sure which actuator fits? Call us at 040 50694631 (Mon–Fri 8 am–5 pm) or use the actuator finder.
