Stone House, cement render, insulated plasterboard??

[theflyingpig]

Hi all,

I'm about to move into an old stone walled house that has been cement rendered. Not a great starting point! Stripping off render and redoing with lime is out of our budget.... and wed like to improve what will doubtlessly be very poor insulation.
What are people's views on adding insulated plasterboard to the inside of the stone walls?

Thanks for any input.
Huey