Timing Interior Plaster / Screed / Exterior Plaster - Topic Moisture

Hello everyone,

I am currently planning the further construction process of our single-family house.
Now I am facing a "timing problem":
My plasterer (doing interior plaster, exterior plaster, and screed) says that after applying the interior plaster and screed, the building should be allowed to dry for 2-3 months before the exterior plaster is applied. It is possible to do it more or less simultaneously, but he explicitly does not recommend this.
Our installer says that this is not necessary and usually interior and exterior plaster are done more or less at the same time.

The problem:
The installer will only start with his rough installation (duration approx. 3-4 weeks) once the windows are installed (which will be the case in about 4 weeks). Then the mason could finish his facing walls by the beginning of August. However, the plasterer has 3 weeks of company vacation and could only start the interior plaster at the end of August. With 2 months drying time, we would then be at November for the exterior plaster, which according to the plasterer is already critical because of the weather. If the schedule goes like this, we probably won’t finish this year anymore.

Now the question arises whether such a long drying period between interior plaster/screed and exterior plaster is really necessary.

Additional information: Solid construction (36 cm exterior walls), during the shell construction (completion about 2 weeks ago including roof) it only rained very shortly once, the building is situated slightly elevated, there is always wind, so the building is quite dry.

What are the experiences regarding this?

At the same time it goes, only inside especially at the ring beam it then dries for a long time. The stone absorbs water on both sides, it has to dry out again.

We also had the plastering done quite close together. The question of whether to let it dry was indeed raised, but the plasterer saw no problem.

The positive thing was: the scaffolding simply stayed up longer, the standby costs were cheaper than dismantling it and having it rebuilt weeks later. By the way, the exterior plaster took about 3 weeks for us, due to the necessary drying times before the next layer could be applied. This should be taken into account if house connections still need to be made under the scaffolding (especially for heating the screed), because our utilities didn’t do any digging until the scaffolding was removed.

Exterior plaster is not needed for moving in. I would have it plastered in the spring and that’s that.