Insulating a rofab house.

I have an elderly aunt that lives in a 'rofab' (concrete panel) bungalow. The house can be quite cold at times and I want to go about insulating it to a higher standard.

I know that external insulation would probably be the best way to go but even with the grant the budget I would have to work with rules that option out.

I removed a piece of plasterboard on an external facing wall to see exactly what was in there. What I saw was the original insulation but it was quite thin, obviously it wasn't very thick to begin with.

What I am thinking of doing is removing the plasterboard on the exterior facing walls, re-insulating, then on with new plasterboard and skim coat.

Someone told me that removing the old insulation and re-insulating could potentially move the dew point into the wall and cause damp issues, so that would make me a wee bit apprehensive.

Does anyone have experience working with this type of construction. I would appreciate any tips.