An international review of occupant-related aspects of building energy codes and standards

In light of recent research, it is evident that occupants are playing an increasingly important role in building energy performance. Around the world, a driving factor for how buildings are designed – and operated in some cases – is the local building codes. Yet, occupant-related aspects of building energy codes have traditionally been simple because: 1) occupants are often seen as a source of uncertainty that cannot be reconciled by current code methodologies and language, and 2) the codes have not kept up with the recent surge of interest and importance of occupants. This paper provides a review of 22 international building energy codes and standards by first comparing quantitative aspects and then analyzing rules and approaches mandated by the codes. The review of requirements for prescriptive and performance path requirements revealed a wide range of occupant-related values, approaches, and attitudes. For example, a key value such as occupant density varies by nearly a factor of three between countries’ codes, which among other things underlines the need for development of locally tailored occupant behaviour models for future occupant-centric building performance standards and codes. Moreover, occupants are often referred to only implicitly; the level of optimism that occupants make energy-saving actions varies greatly; and, only a few codes address occupant feedback and system usability. Based on the findings, a set of initial recommendations for future building energy codes is made. The focus in this paper is offices, though the general recommendations are applicable to other building types.