I thank my hon. Friend for the work that she is doing to ratchet up energy efficiency standards, but may I ask her to address the second part of my question, which is about existing homes? In Birmingham, 35,000 homes in the private sector, and more than half of council homes, do not even meet the decent homes standard, which is a very low standard. What is she doing to improve the energy efficiency of existing homes, particularly those occupied by people on low incomes?