Extractor in toilet room?

[Tubbyewe]

Afternoon all.
New sink and WC being added to attic room. No shower or bath. This "room" will not have a door as such but a curtained doorway (that's what she wants!) into the rest of the attic. The attic has a window that can be opened.
So do regs say I need an extractor fan?
Why try to avoid adding one I hear you ask? Just do it anyway.
Building is listed and extractor will need to go through roof, requiring a longish run and a roofer so extra expense. Cheers.

 

[Donkey Table]

If you have big enough soffits, box the vent pipe down the wall and exit. Failing that get a roofer in to add a prescribed vent through the tiles. Failing that exit into the bedroom below 90 degree exit to hole drilled in wall. You can get a 100mm core drill.

They used to make condensing extractor fans, can find them any more.

Listed building, god help you.

 

[Murdoch]

What does your building control officer say?