The reduction of energy use for artificial lighting in buildings, and its environmental impacts is vital in the effort to combat climate change. Users’ perception of the physical characteristics of lighting controls and user interfaces constitute contextual factors which may support energy conservation behavior and therefore reduce energy used for lighting. However, such factors have not systematically been examined in relation to energy use. This study presents a conceptual framework departing from an explanation of user-product interaction (Desment & Hekkert, 2007), the Theory of Affordances (Gibson, 1979), and the Theory of Planned Behavior (TPB) (Ajzen, 1991) that links characteristics of contextual factors, with psychological factors which jointly might influence energy conservation behavior.

The overarching aim was to examine effects of design characteristics of lighting controls and user interfaces on occupants’ perception and energy conservation behavior (i.e. optimal lighting use) in non-residential buildings. Optimal lighting use refers to when electric lighting is either (i) on when it is needed or (ii) off when it is not needed or (iii) adjusted to meet occupant(s)’ preference.

Through a field study in 18 single-occupant offices, first, self-reported behaviors regarding use of general lighting and presence were compared with behaviors captured on electronic record. Second, occupants’ lighting use was examined with consideration of lighting controls used and seasonal daylight contributions. Of each occupant, a difference in mean values of the lighting use between two seasonal periods was tested. A pilot- (N = 40) and a laboratory study (N = 50) examined whether different designs of the interfaces were perceived differently, with the focus on perceived affordances and usability, and ability to conserve energy of the interfaces. The user perceptions were assessed by using Likert- and semantic rating scales. The relationships among user perceptions of the interface and lighting condition, user behavior, and psychological factors were examined through an empirical study, taking place in shared spaces in two Swedish hospitals. The data were collected using a self-report questionnaire with staff members (N = 31). Non-parametric correlations were used to tested the relationships.

The results show that types of lighting control used and seasonal daylight contributions facilitated optimal lighting use; but for some occupants, their lighting use may have been dependent on habit. This pointed to the importance of selecting lighting control solutions together with changing occupants’ lighting use habit. Regarding the methods, self-report was able to measure the occupants’ lighting use, particularly for short-term. There were effects of different physical characteristics of the user interfaces on users’ perceptions of affordances and usability, and context of use.

It is concluded that lighting controls and user interfaces can support optimal lighting use. The behavior and psychological factors (e.g. attitude towards lighting use) captured by this study could facilitate the decision making in choices of lighting control solutions and modifications of design characteristics that may motivate or trigger energy conservation behavior. The results could also provide a basis for designs promoting energy conservation in non-residential buildings by taking human behaviors into account.