Here you're looking at offcuts of Spacetherm which, cumulatively, are equivalent to one full sheet:

Not only does this represent £450 worth of material, the manufacture and transport of it to site is a contribution to the embodied energy of the refurb.

Aside from ordering one less sheet and doing the cutting differently (hindsight is a wonderful thing, as they say!) the question is: can anything be done with this stuff now? Could the manufacturer take it back and give it to other customers? Unlikely, for commercial reasons; Could it be put on eBay or Freecycle? Well, it's a highly specialised product so chances of someone else looking for this at the same time are minimal; Store it for a future project?  Possible, but it needs to be stored properly given its handling issues, storage space costs money, and even if I do use Spacetherm again it could well be a different thickness anyway.

So here's the building site waste dilemma: it's a well-known phenomenon that a significant amount of all building materials get thrown in skips without even having been used! I'm sad that my Spacetherm will probably be going the same way... not very 'eco-friendly'!