Interesting stuff. There were also a few articles in the last issue of Green Building magazine. Earth floors, cordwood floor, etc. One included empty bottles as an insulation device
I'm doing some work with Ty Mawr's 'glaster' at the moment, and it's lovely stuff - the way the green glass and the the odd bits of blue and brown reflect the light makes it a shame to cover it.
With the amount of bottles we get through, I'm tempted to heave them into the mixer with a few stones and sieve the results to see what we get.
They say it gets very tough but I have been in many places in Taos that have been battered by heavy boots and heels, a friend who runs a B and B in the foothills of the Sangre De Cristos has had to have theirs filled and fixed a few times over the last 10 years but looks great and they also use UFH in one area and it works well.