Some have suggested that the changes that are needed to meet the climate challenge are similar in scale to the Industrial Revolution of the 19th century. And since the built environment is responsible for over half of our energy consumption, most of the changes will need to be made here. For this podcast we talked to engineer Alison Cooke, who manages a project called Energy Efficiency in the Built Environment, and two PhD students at the Centre for sustainable Development in Cambridge, and find out how engineers work with Government, business and other groups to help ensure a sustainable future.