Possible Damp issue / External paint peeling off

Hello all,

So long story short we purchased our house here in the Netherlands in 2019 and there was nothing bad in the report some bits here and there but nothing that needed fixing we had the house repainted last Feb (2023).

After all the recent bad weather we noticed on the extension the paint has stated peeling off in places we also have green mold growing in places (only on the extension)  (outside)

The rest of the original house is fine, so the painter got the SIGMA in to look at it as he has never seen this before. SIGMA came before he even looked at it he said on the phone  he is suspected it to be a damp issue. He came took some readings and some picture and is producing a report but basically is saying we have a damp issue.

Although we get condensation in the extension we don’t think its enough to really cause this problem as there is only a small discoloration above one window in the corner and no black mold etc on the walls

End of the day its SIGMA going to say one thing the painter saying its not my fault and us in the middle.

I guess I need to get an independent damp report so does anyone know where to go for this as I know if I go to a damp proofing company, they will come out do a report and tell me I need damp proofing (so they can do it)

One thing I do know is the previous paint on the extension was different than the original house and done on the cheep as it was fading faster.. so it could be that the painter didn’t do a great job of preparing the surface of the extension before applying the paint…

End of the day I need an independent professional report before I can move forward with what needs to be done and who is going to pay for it… any idea’s