This is all interesting stuff, but it is important to remember that embodied energy of insulants is pretty-much irrelevant, as overall energy is totally dominated by the savings that insulants make. See this (very interesting) report: for lots of details and graphs: http://www.google.co.uk/url?q=http://www.bing.org/DOWNLOAD/DOCS/sustainability_a_guide.pdf&ei=j9b8Sbz8H9rRjAeAz_SoAw&sa=X&oi=spellmeleon_result&resnum=1&ct=result&usg=AFQjCNHSKAVrfd1R1UphmvVbnEXzwjIt7g

I was always amazed that rockwool was economic to make as melting rocks is clearly energy-intensive. It might work in Norway or Iceland, but my rolls came from Wales.

That report makes clear that whilst using greener products is fine is it much more important to maximise performance, so if you use wool rather than PUR (for example), just make sure you achieve the same U-values. I have to agree that is the bottom line. U-values is all-important, embodied energy is very much a side-issue for the geeks.

On new-build it's a lot easier to use the low-energy, thicker wall stuff. For refurb it's usually a much better plan to go for whatever has highest performance at reasonable price.

Soak wool insulation in borax - it's put's off the insects and is about as green as table salt.

(Never heard another tweet out of Mr Rockwool, did we?)