Owning your own home

Be worth it fixing that thing up.

Yeah, that window is great. Definitely makes the room.

Wonder if anything can be done to make that extractor a little bit less of an eyesore (or move it to the wall as part of the bathroom refurb so that the window doesn't have an ugly plastic circle in the middle)?

Quick question, do you want a bath or a shower? a shower would make the room way simpler and easier to design round if you're not the kind who have a bath every now and then.

How long are you planning on living there?

Would be way easier to just blitze a hole through wall and position extractor between window surround and that corner of building. If its done well, and a darker/grey coloured outlet is installed it will look tidy and make your window puzzle a lot easier. AFAIK no planning required for domestic bathroom/kitchen ventilation unless frontage is listed somehow. Conservation areas aren't usually bothered about vents.

Only move around I could see is get a short + wide bath, we got a 'carron quantum se carronite' which is shorter than a regular bath, regular external width (700-750mm) but really really useful internal size for showering. Takes an age to fill as its volumetrically massive, has very steep side walls and a large flat area in the bottom. Defo get a 'carronite' or the higher grade of material (from any bath supplier), bloody hate noisey creaky baths.
Could put a bath sideways across where toilet is, decent shower cubicle (get solid glass, bonded onto bath, no nonsense, no leaks), sink move it onto back of that divider wall (either side) and then relocate toilet to where the bath taps are now. Only way I can see of making that space a bit more logical.

When plumbing up a shower, try to get full size (22mm?) pipes of both h+c from boiler to the bathroom, then split down into 15mm to each fitting from there. It 'shouldn't make a difference to the flow rate of the shower, but defo did in our case.