The previous owners of our flat has put down some fibreglass loft insulation (in the joists, and across them in most places), but then put boxes on top, which compressed it. Then, either we, or any number of other people have walked about up there, lifted insulation and not put it back or whatever.
Anyway, as you may have noticed, it's got pretty cold here in Blighty (even down here in London). Waking up to a cold flat (esp, the bathroom!) motivated me to get the loft sorted out.
A quick trip to Homebase revealed they're selling Earthwool for either £10 a roll, but on a two-for-one deal, or now they seem to be just £5 per roll. Either way - it's an absolute bargain, and apparently carbon-zero to produce. It's super-easy to work with, and whilst you wouldn't want to roll about in the stuff, it's a lot more pleasant than the old fibreglass stuff.
I can fully recommend getting up in your loft and plumping up your insulation a bit. Even the fibreglass stuff is cheap if you want that, and it's made one heck of a difference to our flat. It's colder now than when I started the work, and the flat is warmer, heats up more quickly, loses heat more slowly and generally just feels a bit cosier than it used to.
I went a bit crazy and did loads of work on the job. I pulled up all the old fibre glass stuff from one side of the loft and piled it on top of the other side. I also put down lots of boarding on top of some 2x4 (we had some old doors, shelves etc up there, so I just used those). Right now, even under the boarding, we've got about 200mm of insulation. Elsewhere, it's more like 350mm. I was aiming to make sure that even in the low bits, it's still at least 270mm (like the Part L regulations require for new builds).
Including the 2x4 and the Earthwool, I reckon I've spent about £100 in materials, and a couple of days of my time. If I hadn't have done the boarding, I'd have spent about £50 and probably an afternoon. I reckon if there had been absolutely no insulation at all, I'd have probably only put up about £100 worth of Earthwool. Best money I've ever spent
