Terrace without slope - From which DIN / regulation?

There is a ZDB fact sheet for terrace coverings, unfortunately only for a fee. Apparently, the craftsman does not care about it. A slope of 1.5% should be maintained.

Did she actually measure a slope of ZERO or was the spirit level just placed on it briefly?

Enlighten us, where does the instruction consist?
A gradient must be carried out constantly, not stepwise, wave-like or randomly distributed...

You’re not seriously suggesting that something like this has to be measured with a laser now?

Thank you very much for all the feedback.

I first checked this with a spirit level and then also measured the slope as best as possible. Depending on the measurement point, it is about 0.25% away from the house.

Yes, then that’s crap. Don’t let yourself be driven crazy here, it is really unpredictable where the pendulum will swing. Sometimes the craftsmen are directly demonized, sometimes the client, that is you, is accused without any reason of not having "measured" correctly or your competence to judge such a thing is denied.

With some specialists here, I really also doubt that they have ever held a spirit level themselves and/or have ever created a slope or aligned something level... because in practice every craftsman first checks their work with a spirit level. Whether it’s the carpenter installing a door frame, the bricklayer checking his masonry wall, or the landscape gardener setting block steps, curbstones, or a terrace. And if the air bubble is within the inner markings... then that is considered level and has absolutely nothing to do with slope.

That is, depending on the measuring point, about 0.25% away from the house.

That is too little.
How is the transition from the terrace to the house wall? Is there contact with the timber construction or with a base plate or concrete?