@TedM, I know the political drive and the mechanims here are clearly two different things.
However with what you've just said, on ECO, that confirms my appproach above - I should have expanded it a bit ' Mrs Bloggins wants EWI - that has an ECO grant of x, so will cost you y, - here's how you could pay for it ' and a criteria would be that the value of the ECO is to make sure it fits a (new) Golden Rule, else no ECO grant/subsidy i.e just beacuse I don't want to finance it via the Green Deal Loan, doesn't mean I can't get the ECO element.
Of course, seeing as you will (I believe this is one of the rules) be able to pay off your Green Deal loan at any time without penalty, perhaps we are going to see a lot of smart re-financing and a lot of 'missold' green deal claiming companies springing up to help people get out of it. I just can't see REAL doing a good enough job on this and being able to manage it let alone police it properly.