Leaving lights on – A conscious choice or wasted light? Use of indoor lighting in Swedish homes

Abstract

Promoting resource- and energy-efficient home lighting through technology and behaviour change requires an understanding of how residents currently use lighting and what they want from it. However, users' needs and desires relating to lighting in homes are poorly understood, as research is still limited. This paper aims to provide a fuller picture of residents' experiences with their home lighting. Interviews about how residents perceive the character of lighting and luminaires and lighting use suggest that home lighting has nine capabilities: to enable vision; to facilitate visual tasks; to display objects; to send a message; to support a particular atmosphere; to shape the architectural space; to offer a visual aesthetic experience; to maintain or change rhythmicity; and to evoke memories. Secondary data confirmed five of them. The identified capabilities relate to behavioural goals, psychological wellbeing and social needs. We conclude that seemingly wasted light in people's homes, i.e. lights left on in unoccupied rooms, can serve a purpose for the residents, such as avoiding visual or aesthetic discomfort, making the home inviting, benefitting people outside and providing safety. Findings have implications for the further development of new lighting technologies and design, energy-saving campaigns targeting residents and for urban outdoor environments.