From what height it is permitted for loads to project up to 50 cm in front of your vehicle?

The key rule is that loads may normally not project forward beyond the front of the vehicle. An exception is allowed only when the load is so high that it does not pose the typical danger of “spearing” into traffic at car height.

That’s why the law sets a minimum height: if the projecting part of the load is at least 2.50 m above the road surface, it may extend up to 50 cm in front of the vehicle. Below 2.50 m, no forward projection is permitted.

Rule of thumb for similar questions: forward overhang is basically forbidden; only a small forward overhang (50 cm) is allowed, and only if it starts high up (from 2.50 m).