While we were away M made great progress with insulating. He managed to fit in some celotex between the rafters in the narrow parts of the roof space, so we wont have to insulate within the room. The tricky bits were the dormer windows, because the walls there are very thin and there is no insulation, so M had to take the plaster off there and also in part of the hallway ceiling, as that was the only way to get the celotex in.
Although some mineral wool was laid by the roofers 10 years ago, it was done in a very piecemeal fashion, and has got lots of rubble mixed in with it, which probably reduces its effectiveness. M is lifting floorboards and adding sheep's wool insulation where there are gaps. The house already feels much cosier.