On 2007-05-17 12:23:10 +0100, Stuart Noble
said:

But, to go back to the original point, it is indeed surprising that
*any* thickness of insulation makes a huge difference. The problem is
the lack of any material that you can stick on the wall and decorate. I
lived in a house with polystyrene lined walls 40 years ago. Cheap and
easy, but so vulnerable to knocks that it wasn't practical. Even then
people were lining their walls with vinyl cushion floor. I lined an
exposed room with cork in the 70s. Difficult to believe there aren't
better solutions out there now.

There are. It's called Celotex.

The question then becomes one of how much is one willing to lose from
the room dimensions.

50mm sheet would go some way towards modern standards. Installation
would imply 75-100mm reduction in room dimension once finished.
There are then the joinery (window reveals and skirting) and
redecoration issues (walls, floor coverings, ceilings) to address, so
although simple in principle there is a lot in the implementation.