Tall buildings are a major source of carbon emissions due to vast quantities of energy required to heat, cool and ventilate them. The survival of tall buildings in our urban landscapes depends on their ability to consume less energy and to function more harmoniously with neighbours, as well as be adaptable for climate change. Technological advances in active and passive sustainable design mean that buildings of today can benefit from more energy efficient, low carbon systems than their predecessors. Innovatively designed new-builds now have facades with integrated passive attributes and cooling strategies to counter solar gain – major concern for building tall and green; and where an entire urban district is already suffering from the effects of high-density development and pollution, there is also a green answer: vegetation on walls and roofs to reduce the tendency for new additions to absorb and radiate heat. Sizeable openings in new buildings can also encourage cross-ventilation so that warm, polluted air can disperse.