We will develop the proposals after we have received the results of the consultation. We want this to be a workable, practical way for zero-carbon homes to be built by house builders of all sizes, but one thing we will certainly do when we introduce the secondary
legislation that will probably be necessary is to ensure that there can be no gaming of the system by anyone. I hope that gives my right hon. Friend some reassurance.
Let me now say something about the energy provisions. Britain needs more home-grown energy. We expect to be importing nearly 70% of the gas that we consume by 2025 if we do not develop other sources such as shale. We must maximise domestic production of the fuels that we need for the transition to a low-carbon economy, including gas, renewables and new nuclear, and we must use our energy more wisely.