But there are other equally important reasons for improving end use efﬁciency. Conventional or fossil fuels are highly polluting. Reducing use has both environmental and health beneﬁts. Those on ﬁxed incomes such as the elderly are vulnerable to fuel poverty and higher efﬁciencies can reduce the amount spent on fuel. Improving efﬁciency is both a technological and social challenge. Policy makers are now focusing on ways in which different policy instruments can inﬂuence technological developments and behaviour with respect to energy efﬁciency. This chapter explores developments in the transport sector, the built environment and in goods, appliances and electrical motor systems.