Roof Tile Vent - Best Practice for Bathroom?

Hi,

I live in Glasgow in an old tenement building, top floor (2nd floor). I want to get my bathroom renovated, but I'm concerned about the ceiling and ventilation in the bathroom.

On the ceiling I have wooden planks and believe there is a cavity between the ceiling and loft to aid ventaliation. My goal is to sort the ceiling out when I renovate the bathroom. Potentially extending the ceiling higher up to give more space, but don't really know if this is possible and what the best practices are.

To confuse matters further, there are some vents on the side of the wall and it appears the air is expelled on the other side of the wall (outside my front door, pictured with the teal paint), but I'm not sure. My neighbours extractor fan definitely ventilates air in the same position into the hallway, I don't even know if this is strictly legal??

I've spoken to a plumber who doesn't go near these types of jobs, and before engaging with roofing and building contractors, I'd really like to gain a bit more knowledge about this, so I don't get ripped off. Does anyone have knowledge of this type of setup? Or do I just have to pay a contractor to spend a half day to assess the job?

Any advice appreciated. Please see photos attached.

Ther's a number of issues:

Its against English Regs to ventilate into a public interior space - BCO pulled a landlord on a job for that.

The wood panelling on the b/r ceiling is a very bad idea. Dropping ceilings is often to retain heat not to ventilate.

Why not isolate the extractor & all electrics leading into the bathroom - all of it, and test its off - check check check.
Given the DIY nature of what you show then its possible that the special elec Regs for bathrooms were not followed - things could be sketchy esp if you have an elec shower, so whatever happens next get a proper sparkie in to re-wire and inspect - dont DIY it.

And then remove the boards, the extractor, and all the other fitments - expose whats going on above & why you have so many vents and whats going where?

Without seeing whats happening above there's no way i could advise you further.

Hi,

Thank you I will get an electrician and building company in to inspect what's going on.

Fine but how will any builder be able "to inspect whats going on" without opening up the ceiling as advised above?