Can I insulate inside cupboard?

Hi all

I have a neighbour who has asked me to fix thermal insulation foil (supplied on a roll) to the inside of her cupboard as the room gets cold when the cupboard door is opened. The cupboard is in a bedroom and is built into the slope of the roof ( it is not a loft conversion) the inside of the cupboard is plaster boarded and artexed as though it were part of the ceiling. It is approximately 3mtrs wide x 2mtrs high x 1mtr deep at floor level.

I have seen on the market some foil which claims to be the equivelant of 55mm isulation and wondered if it was worth getting. Can this be pasted to the sloping wall or stapled?).

I'm a bit concerned that because the foil works by relecting heat, it wouldn't work when the cupboard door is shut??

I did mention about battening the wall, inserting isulation and then re-boarding but I don't think she wants to spend to much on it. Also she would lose a bit on the cupboard space over all.

Any ides would be appreciated.

Thanks very much

BUMP!

if its cold with the door open i would have thought its more off a draught problem!!

whats normaly stored in the cupboard!!