The implementation of energyefficient artificial lighting has been accompanied by a compelling narrative of savings in economic terms. However, this obscures significant costs to the environment, humans and non-humans. It has also led to higher levels of brightness at night. Integral to this process is the loss of nocturnal atmospheres and ambiances as access to darkness becomes further limited. We need new ways to address this ongoing extinction of experience of the nocturnal commons. Design can provide a valuable role in its ability to explore alternatives, to speculate on new sensitizations that enable nocturnal urban ambiances to be reimagined. This paper proposes an emerging field of ‘Dark Design’ as advocacy for change of existing beliefs concerning artificial lighting and darkness.