Cold external walls

[Croissantsandpistachio]

Does anyone have any experience of warming up cold exterior walls?

DC2 has the back bedroom of our Victorian mid terrace. It's the smallest room but has 2 exterior walls (each with a window, they're double layer brick construction). It's the coldest room in the house in the winter and the hottest in summer- and the 2 external walls are themselves pretty cold (although not too damp prone, we open windows a lot). I don't think we can do external insulation without a condensation problem, and the internal would remove too much floor space.

Warmer walls would definitely help it feel cosier- one of them has the radiator along it which helps but also probably means all the heat is going straight out through the wall.

Is insulating paint snake oil? Or is there something else we could do to warm it up? The overall EPC for the house is a C thanks to new loft insulation and a new boiler so it's not a cold house by any means (although the space over this room doesn't actually have the thicker insulation- we have a weird roof construction). Thanks!

Copy paste from an email I sent myself when friends told me about it last year.

Wall rock thermal liner by anaglypta

Various standards, they got the one £50-51 a roll

£20 of paste lasts two rolls, needs to be applied with a roller

Used to have to have the room on 6, now has it on 4, sometimes 2 when it gets too hot, sometimes off completely when John in the room

They googled it and it's the equivalent of 3 breeze blocks

Don't have to take the skirting board or electric sockets off

Structure they put it on is a wood frame with
plasterboard

Before you do any insulating, double check the gutters are ok. If there were leaking then the dampness of the walls would make the room feel much colder than if the walls are totally dry.

I have also heard that the insulating wallpaper can be good. If you want to do more then there is insulatin plaster you can use too but you would need to get the room taken back to brick to use it.

Just to add, my friends got a painter and decorator to do it, apparently it's not all that easy to work with.

Yep, the gutters are fine now (had a recent issue but the cold walls predate that). We can't really get it taken back to brick but might be getting a small loft extension on top of it next year, so I guess could look into something external and breathable while the scaffold is up anyway. I might be tempted to have a go at the paper but not sure if I'll be able to do it!

Try posting on Your Old House UK on Facebook too.

Insulating wallpaper like mentioned above. It is great.

I love Your Old House. The answer to literally everything is 'lime'. (Also very jealous of people finding loads of original features hidden away in their house- ours was bombed in WW2, half rebuilt and seemed to use the opportunity to lose absolutely every original feature).