Cold and mouldy bay window

JuzaMum

I have a cupboard built into the bay window in my bedroom. Inside the cupboard it is mouldy (black spots, not thick) and you can feel the cold coming in when you open the door. When my neighbour was having his house re-rendered it looked like it the bay was covered with lath(?) then render on the outside so I assume mine is the same. I have horrible peddledash render which is damaged.
What would be the best thing to improve this? Obviously cleaning the mould off! I was thinking maybe dismantle the cupboard and wallpaper the bay with a polystyrene type wallpaper?
In time we hope to re-render the house but we are waiting for the money fairy to arrive first.
Thanks for reading

Doozergirl

Insulation. It’s cold in your box with no airflow. You could really just pack solid insulation like Celotex against the back of your inbuilt unit. It can be cut to size easily. And possibly drill some holes for a little bit of ventilation if you can make them look attractive.

missprice

Agree with doozergirl.
Our bay window upstairs was cold so as the whole house needed re plastered we used insulated plasterboard over the entire bay and insulated the ceiling in the bay. Made a huge difference to the overall temperature in that room.
Lost some height in the ceiling but as it's not useful space am unbothered

PhilE

Try a dehumidifier. Leave the cupboard door open during the day, or when your not at home. Make sure the room is heated, but still open the windows for about 40 mins per day.

Lack of heat and ventilation is what causes condensation. Im presuming that your radiator/heat source is on the other side of the room, or not close to the bay window.

Condensation around bay windows is common, for the simple reason that radiators aren't usually installed underneath the bay window. Double glazing can actually contribute to condensation, as it traps vapor. The area around the bay window then becomes a condensation spot, which is susceptible to mold.

I've solved a similar issue with an Ebac dehumidifier.