This lecture describes the developments in built environment technologies that are influencing the Government's thinking for its vision for 2050. With more than half the world's population now living in a built environment and China anticipating that 300 million people will move from the countryside to the city in the next 15 years, the impact on our cities' infrastructure and systems has never been more apparent. The lecture offers an insight into current thinking as we face these engineering challenges, and asks whether we have made any progress towards creating a smarter planet.