For some of those old houses, it may not be feasible to insulate them efficiently, there's no sense fretting at a small proportion of the housing stock; for others, there will be sensible and cost-effective insulation strategies where money might be better spent.
As an ordinary home-owner who doesn't appear to qualify for any grants, it seemed a bit impossiblolium to get anyone to give us a quote on solar panels/solar hot water on our roof (admittedly, it seemed more hassle than it was worth, so I let it slide, but that's the problem with relying on individuals).