Insulating cold wall (internal insulation onto external wall)

[Diybeginner201]

I want to insulate a cold wall that is inside a large built in wardrobe. The wall is an external facing one (its an external wall internally in the garage if that makes sense).

I dont know if its got cavity wall insulation or not. Ideally I would like to put 25mm insulation board straight onto the wall - the wardrobes have ikea shells inside them which are screwed to the wall so would push the insulation tight against the brick wall. Would this work ok assuming i make sure the insulation boards are tight together etc or would i get issues with condensation or similar?

 

[oldbutnotdead]

It'll work. Might want to go a bit thicker on the insulation...and yes if the insulation is hard to the wall and you seal all the joins properly you won't get condensation behind it