Government were running a scheme not so long ago which enabled you to get it done either free or subsidised. Not sure if it is still going though.
The govt scheme was called Warm Front scheme. There are a few others though. Just use google. Try here. http://www.green-insulation.co.uk/insulation/
low income! tax credit! get it done for nowt. Not that i have mine done, i bought a old pit house, fooking walls are 2 foot thick solid concrete...build to last, none of this build a house in 5 mins ******..