A design process for a resident-oriented, sufficiency-based energy renovation approach for dwellings

Abstract

Energy efficiency of houses is considered a key measure against climate change. However, its characteristics jeopardize effective energy savings. Firstly, the use of a relative scale to express energy efficiency, in kWh per m² floor area, neglects the impact of building size on absolute energy use. Secondly, the use of standardised norms for thermal comfort neglects how residents are effectively using the space in their homes. And thirdly, the abstraction of the social context ignores the actual and dynamic behaviour and wellbeing of the residents. In order to put the final objective of lowering the absolute energy use in houses in the front seat of our research, without neglecting the needs of residents, we abandoned the focus on the house as the object to be optimised by improving its energy efficiency. Instead we explored the potential of energy sufficiency in dwelling (as an act) by means of the three types of interventions that are documented in literature on sufficiency. We applied the interventions of reduction, adjustment and substitution of dwelling-related energy services, especially heating and cooling, to meet the residents’ basic needs such that the provided service is enough whilst avoiding too much of a service. To do so, we firstly investigated the dynamic way of living of residents over the seasons, especially in large, underused houses, via ethnographic interviews and diaries. Then, through research-by-design we explored the potential of spatial design on dwelling and room level to stimulate sufficient behaviour of an active resident and to optimise (thermal) wellbeing of a diverse resident. These stages informed the development process of a design instrument to support architects to increase energy sufficiency in (large, underused) dwellings. The instrument was iteratively tested and optimised in four design experiments, over four subsequent academic years, with novice (student) designers. By shifting from an object-centred towards a resident-oriented perspective we were able to develop a design process for an alternative sufficiency-based energy renovation approach. The process involves three main steps (analysis, synthesis, evaluation) and the implementation of design methods (grouping, linking and zoning and flexible spaces/places). Based on place-making (identifying places, meaning of places, meaning of spaces), energy sufficiency can be increased by reduction of space, adjustment of energy services, and substitution of active output/practices. A qualitative evaluation scheme with design criteria, boundary conditions and critical questions is provided to evaluate the impact of the renovation design on the overall energy consumption.