Insulating solid external walls

[woogas]

Hi.
The small window in the 1st pic is the fully tiled (floor to ceiling) bathroom.
This wall is solid and no cavity.
The porch side wall is also solid, this time single skin.
The occupiers are experiencing lots of condensation build up on the internal wall tiles, especially and internal plaster wall of the porch. Some is expected when showering.
The window is always open (although no trickle vent) and the extractor works and has good pull.
The porch wall has had one of those passive vents fitted which presumably pull out the moisture, so someone has historically tried to rectify.

What is the option other than to insulate and render externally.

It's only the ground floor flat and does not include property/window to the left.

We are aware the render is cracked and needs chipping out anyway.

Any advice please.

 

[^woody^]

What is the option other than to insulate and render externally.

1. Insulate internally
2. Do nothing.
3. Turn the heating up

 

[endecotp]

If the fan is on and the window is open, it will draw in air through the window which is just below it. The moist air from the shower won't be affected.

Is there any heating in the porch? What sort of internal door is there?

 

[woogas]

They have an electric fan heater wall mounted in bathroom and electric convector heater in porch.

The fan to open window scenario seems to be what's happening