From when must the shell construction be dry or sealed?

We built on a hillside. The shell is up, meaning the roof and windows are installed. The plasterer is currently working, and the screed is supposed to follow.

Today, after heavy rain, I noticed water ingress at a corner on the ground floor.

Shouldn't the shell already be watertight? Or only after the screed is laid?

I am really desperate, as you can tell by the time.

When the roof is on, in my opinion it should be watertight. Are there dormers or other typical spots above it? Be glad that it is noticed now and not later. That was the case with us too.

When I think about our construction... no, it doesn’t have to be sealed yet. There can still be cracks and holes in the stones where rain can get in during strong winds. It should only be really sealed with the insulation. But I’m not an expert either.

The wall adjoins the garage and then continues into the ground. In other words, a lot will happen there. It is a hillside location. However, the garage roof is not yet sealed.

Inform construction companies and talk to them.

When I think about our construction ... no, it doesn't have to be watertight yet. There can still be cracks and holes in the bricks where rain can get in during strong winds. It should really be watertight only after insulation. But I'm not an expert on this.

That looks like Poroton. So only the plaster would come from the outside. So what kind of insulation? Good to see something like this, I will pay more attention to it myself.