Alusimse damaged

Every trade has or should have liability insurance that covers such damages - in this case, the cleaning company :)
Deficiency report to the house construction company with (acceptable) deadline, e.g. 3 months.

Hello

Thank you for your responses.

Yes, we have a new building. No, they are not scratches, to us it looks as if the anodized surface is damaged (eaten away by the plastering work).

We will definitely bring in an expert who will take a look at the windowsill.

We will definitely bring in an expert who should take a look at the window sills.

Why an expert?

For obvious defects, a defect notice without an expert is sufficient.
An expert assesses what you as a layperson cannot assess.
A visible damage or defect does not need to be confirmed by an expert.