Reducing energy use is the single biggest challenge facing architecture today. From the humblest prehistoric hut to the imposing monuments of Rome or Egypt to super-connected modern airports, buildings in every era and place have been shaped by the energy available for their construction and running. This survey tells the story of our buildings from our hunter-gatherer origins to the age of fossil-fuel dependence, and shows how architecture has been influenced by designers, builders and societies adapting to changing energy contexts. It is a celebration of human ingenuity and creativity, and a timely reminder of the scale of the task ahead in our search for truly sustainable architecture.