This is Pavatex Wood Fibre insulation being very neatly installed by the contractor at our sustainable retrofit project near Corbridge.
The existing external envelope was stripped back to sadly reveal 30mm of sagging, rotting and discoloured glass mineral wool. This has now all been removed and safely disposed of.
The multiple tightly packed layers of wood fibre will create a large thermal mass. This will allow the building to self-regulate its internal temperature through the absorption, storage and releasing of heat.