The quality of the environment is conceptualized in this study as the extent to which it facilitates or hinders participation in activity outdoors. Thus, we call this quality the ‘supportiveness’ of the environment. Given that older people vary greatly in terms of lifestyle and functional capabilities, it is important to consider individual differences in the process of assessing supportiveness. The same environment may have different degrees of supportiveness for different people. In this sense, supportiveness is not a simple environmental construct, but is derived from the interaction between environmental and individual attributes. Based on this principle, we have developed two instruments to measure the supportiveness of the outdoor environment. One method takes account of individual needs and desires through a focus on the specific behaviours in which a person engages (or wishes to) in an outdoor setting, while the other looks at specific environmental attributes that have been identified empirically as relevant to people’s use of the environment.