28 May 2012 Update:

I put a post on greenbuildingforum.co.uk and the consistent reply is that it’s more expensive than well used and well know Leca, which is usually used with a breathable Limecrete floor. I’m not sure if it’d work / work as well under a non breathing floor.

http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=9113&page=1#Comment_147104

I was at a Green Building show / expo / day at the Eden Project last week and there was a talk by a German sounding chap, who is part of the UK Epoc Europe Ltd team promoting / pushing their TECHNOpor (Recycled Foamed Glass).

The key points seemed to be:

• uses 100% (or close to 100%) recycled materials (glass bottles etc.)
• German factory is powered by HEP electricity.
• light to transport on low emmisions trucks from Germany.
• easy to work with.
• good insulation values for under the floor, behind retaining walls.
• can even be used for between floor and in ceilings insulation (as super light).

I’ve found 2 UK Websites related to this:

• http://www.misapor.ch/sites/index.php?PID=28-72-0&NID=23-72-0&lyd=1&lang=EN – Swiss
• http://www.lime.org.uk/products/limecrete-floor/components/technopor-recycled-foamed-glass/ – Welsh

The German site for TECHNOpor is http://www.technopor.com/English/Granulat/

The Swiss site has a great idea of using bags for when you use the Recycled Foam Glass to insulate a wall. Given that there will be 2 retaining walls, this could be great.

From www.misapor.ch: