Cracking bathroom walls after extension

[MattT]

We are looking at a property and it had an extension 2 years ago (the now typical thing where the back is extended out to create a large kitchen/entertaining space with big sliding doors at the back.

There was a big RSJ put across the original back wall to allow this (the extension is about 9.7m wide by 5m) , we can see it in the new open kitchen/entertaining space, as it's an exposed RSJ as part of the decor (see picture).

However there are two bathrooms on that back wall and they both show signs of movement on the back wall but also one tile on the inner partition, albeit seemingly nothing on the external walls apart from a bit of loose pointing. What are your thoughts, anything to worry about?

I would get it checked via a survey, but keen to know if it's normal or not?

 

[foxhole]

Externally looks like gutter is short allowing rain to flush down wall off roof.
Sealant in bathroom is pants, fan is ineffective or not working causing mould over shower . Loose tile in shower could cause problems .

 

[MattT]

What is also interesting, but perhaps in tolerance, you can see the different coloured tiles. I wondered why they were there. But seemingly they had some movement and maybe the tile cracked, so they found a replacement put those in and you can see the thicker grouting around those particular tiles. It doesn't seem a HUGE difference but clearly there is one. Then at the bottom where the floor connects to the wall, seemingly a suitable sized gap, hence that sealant.