Started the proceess by talking to those with the money and therefore the power. So far, it looks positive from the banks about getting the sort of money we'd like, so it's more a question on repayments. Of course, we have to decide what to do with our existing house. In this climate selling is a poor option, but renting is hassle, and personally I think likely to dry up as houses move into a more affordable level. But we don't need to fully decide that until we're ready to move out of it, so who knows then.
Also - realised that the government grants for sustainable initatives are gone for new construction. Basically, as some element of renewable energy is required in every house when the next set of building regulations come in, there is no need to incentivise people to get it! It's reasonable of course, just removes some of the safety net around costs.