Impact of sustainable building design on occupant experience: A human centered approach

All too often sustainability in building design is decoupled from user experience. This paper discusses how user comfort, well-being and performance should be put at the centre of the design process and how work beginning at Bath and Exeter, using the newly built VSimulators facility, is helping shape this. From a structural perspective, the drive to reduce material use, the use of more sustainable materials (e.g. CLT) and the desire to improve structural efficiency can lead to building designs which are not governed by ultimate limit state criteria, but rather by serviceability limit states. Reduced stiffness, in particular, leads to undesirable floor vibrations and/or sway in tall buildings. The question arises as to what is an acceptable level of vibration or motion. While it is a relatively simple task to define perception thresholds, acceptability is an altogether more complex problem. Subjective measures of acceptability vary significantly from person to person and is situation, context and task dependent. What's more, it is not just vibrations that affect the acceptability of the indoor building environment; temperature, humidity, air quality, lighting, noise, even smell, all have an influence on whether a building is fit for purpose. Sustainable construction practices, such as passive house design and air tightness, can lead to poor environmental conditions (e.g. increased concentrations of VOCs) unless we consider the impact on the occupants. Thus, the work being carried out using the VSimulator facility aims to understand these complex interactions between structural, environmental and human factors, using a multidisciplinary approach involving psychology, physiology, engineering, building physics and health. The challenges this issue poses and the unique facilities developed to address these challenges are described in this paper.