Well, then, how are we going to get to the targets?

Given the mucking around going on in Australia around voluntary versus mandatory approaches to energy efficiency, this news as reported in The Guardian is probably not good news...

All the mandatory elements of the government's green deal for homes are to be scrapped following an intervention by the prime minister.
The decision, which is a blow for the Liberal Democrats, means that the government will reject proposals currently out for consultation by the Department for Communities and Local Government that would have required homeowners to make their homes more energy efficient if they were undertaking home improvements, such as extending a garage or replacing windows.
... (and) that any homeowner intending to make a property more energy-hungry by building an extension, should redress the balance by improving insulation, upgrading a boiler or adding better heating controls.
The homeowner would be required to spend 10% in addition to the cost of the main works; so if building a £1,000 new patio, an additional £100-worth of energy efficiency measures, such as loft or cavity insulation would have to be installed.
The money would go to local contractors, paid for through cheap finance provided by the green deal and repaid through subsequent lower energy bills.
...
The source stressed that No 10 was not opposed to the green deal itself so long as it remained voluntary.