Why do we need greener buildings? What is a carbon footprint? How can computer-aided design help reduce our energy use? The 'Why Science Matters' series demonstrates how the science we learn at school is important in every aspect of our everyday lives. Using case studies and investigations, the series describes the development of science and technologies that can improve our lives – or lead to new scientific challenges and controversies. 'Designing Greener Vehicles and Buildings' investigates how our transport systems and buildings affect the environment. We find out about energy transfers, the importance of renewable building resources and energy sources, and the science behind solar panels and hybrid fuel cars. And we learn about the cutting-edge innovations in architecture and vehicle design that will help us to reduce our energy.