Single skinned cloakroom

Hi all,
We have a downstairs cloakroom (Extension) off the kitchen which is single skinned brick, tiled on the inside with a rendered exterior.
This time of year it gets really cold in there and now the rest of the property has had cavity wall insulation installed I am noticing condensation gathering on the tiles in there as its now the coldest part of the house.

I am looking to insulate both exterior walls, but first looking for advice on the best way forward.
The 2 exterior walls that need insulating, are both approx 4m2.

If I insulate internally would it be best to remove the tiles first or could I insulate over these and fit plasterboard.

it is true to say (regards insulation) the more the merrier.

up to the present days regulations, a 100mm single leaf wall would probably require as much as 125mm of celotex type insulation.

this is not to say that every little helps. it is to what level of insulation you require, how much space you wish to lose and to how much you want to spend.

you could for instance either dab or batten fix some polystyrene backed boards to the walls, but you may suffer future condensation and subsequent black mould.

if you chose to batten, then the tiles could remain. you could probably dab directly onto tiles also but i would not recommend this in every scenario. rendered-on tiles only.

the building could be insulated externally but this would require more thought as the finished article would be a rendered/stucco finish and would effect the soffit and any openings.

Thanks for the quick reply, over a few beers last night I discussed my predicament with a local plasterer who explained something similar to yourself, he is coming to have a look on Monday.

Cheers