See the difference between settlement damage or just bad plastering

[ZipLock]

A relative is interested in a co-op apartment in a building from the 1920s. The apartment requires some renovation, but one thing made him a bit hesitant.

All the walls are plastered and then painted or wallpapered. The plaster had a lot of cracks, for example around the windows, at the junction with the ceiling, and when you knocked on the wallpapered walls, it sounded a bit hollow behind. I've learned that this means the plaster has detached behind the wallpaper.

Now the question is: Since the apartment is going to be renovated anyway, my relative isn't too afraid to hire a mason to repair damaged plaster, but how does one know if it's "just" damaged plaster or something worse, like settling damage in the building?

 

[etiol]

as I have been taught by experienced bricklayers, if there is a hollow sound when you tap, then it has detached (kaka)
and if there are cracks, it could be a settling of the house and if you then replaster, it might come back.
.. but get a bricklayer to check it and let him decide. that's probably the simplest solution..
Eti..

 

[ZipLock]

Yes, for the damage inside the apartment, it's good to get input from a mason, but I was wondering if there are any indications that the house is moving. My relative doesn’t want to buy into a co-op where there is a risk of large costs for things like foundation reinforcement.

The property has three floors with a basement and the foundation/basement was excavated and drained three years ago.

 

[etiol]

what do the facades look like on the outside, have you examined them closely???
And what have you found in that case..
Eti..