iirc the £3 a roll thing was wrong and it actually went through at 1 a roll.
Just found my receipts frm B&Q – £3 for each “tube” containing 3 rolls of 4m, at the time priced at £7.49 per “tube”.
Who’s paying for it? Energy users – they’re subsidised by (generally) the power industry who need to do so to offset their carbon output (some sort of government mandate I think) – their way of paying for their damage is to offer subsidy on insulation. Which means that all of those not taking up the cheap offer are paying for it (more so than those who do use it). It’s a bit like the solar FIT system, if you’re not doing it you’re paying for it through higher bills, so you might as well if the numbers work out.
Incidentally, you’ll get better effect from laying your insulation cross-joist if you can – you reduce the number of thermal bridges between the outside world and your ceilings.
I suppose another option is to leave the existing insulation where it is and simply roll some new over the top and see how much that helps… then I don’t need to buy as much
That’s the obvious solution (and the one I took).