Drainage channels in front of terrace doors

Hello everyone,

We have 3 large sliding doors from the living/dining/kitchen area to the terrace. The terrace is partially covered by a balcony (with its own drainage). One door is protected under the balcony, 2 doors are uncovered. The terrace is to be connected barrier-free (<2cm step).

Do I only need a drainage channel in front of the 2 uncovered sliding doors or also at the covered sliding door?

Thank you in advance.

According to the standard, yes for the uncovered ones. For the covered ones, it depends on how they are covered. Everything can be individually agreed upon if you do not want a gutter. But then do not complain afterwards if there are problems. The gutter must be 15cm wide.