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.
A while since the last entry... we've now taken delivery of £4,500-worth of Spacetherm, for internally insulating the front wall (see article for a more detailed description). As the delivery was on an 18-tonne truck, we had to decant it into my 3.5-tonne van in order to get as close as possible to the house. The contractors are using their joiner to fit the Spacetherm: a slightly curious choice, but makes sense given that there's some difficult angles around the bay windows, and cutting the stuff neatly will be half the battle.
Retro-fitting insulation to the walls of an existing building is a tricky subject, with much of the theory yet to be substantiated by real-world experience. However, the general consensus seems to be that external wall insulation (EWI) is the preferred option. The key issue is the movement of moisture within the building fabric. For EWI, as long as the insulation material itself is vapour-permeable enough, any moisture within the wall will find its way to the outside.
