Retrofit Electrochromic Glazing: A longitudinal case study of occupant experience

Electrochromic (EC) glazing has emerged as an alternative to traditional forms of glazing. It has the potential to enable occupants to control daylight ingress without the use of blinds, giving users more access to daylight with all its inherent benefits. Research efforts to date have been mainly focussed on the potential of EC glazing as an energy saving technology through the reduction of electric lighting and air conditioning energy loads, using scale models, computer simulations and full scale test rooms. Few studies have considered the user experience of the technology, and none of the studies that have included data from human participants have been carried out in a real-world research setting over a long-term period. Thus, there is a general lack of understanding regarding the performance and suitability of EC glazing in real-world working environments. To address this gap in research, a new study of EC glazing was undertaken, looking at the experience of occupants working in an office that had been retrofitted with EC-glazed windows. The retrofit was the first of its kind in the UK, and provided an opportunity to study the user experience of EC glazing in a real-world setting over a longitudinal period. The aims of the study were to gain new insights into the experience of users of EC glazing, and to learn about the practicalities of installing it. A number of research questions were defined, leading to a mixed methods data collection programme, carried out over a period of almost 18 months. The data collection encompassed data from the occupants as well as from the physical environment, and was designed in response to the constraints of the site and occupants, as well as the aims of the research enquiry. The resulting data set includes a valuable record of occupant experiences and behaviour, as well as detailed information about environmental conditions at key times. A number of contextual factors influencing the effectiveness of EC glazing were identified. The outcomes of this research provide a new understanding of the user experience of EC glazing, and thus can inform further technological development and benefit future installations