measures using a talk aloud approach. A subset of interviews was conducted with dementia care practitioners (N1⁄4 55). Findings were analyzed using a thematic approach assisted by Atlas.ti. Results:The internal and external physical environment as a specific source of stress was less understood by participants, carers and practitioners. While dyads often made adjustments to mediate the strain caused by perceptual challenges these were largely ‘trial and error’ attempts rather than in response to research informed advice normally available for other stressors associated with dementia. Additionally, the strain associated with the physical environment was layered with strain that originated in the psychosocial environment and these interacted with one another in a complex manner. Conclusions: The SPM provided a helpful, but sometimes limited, understanding of the illness and caring experience by highlighting the nature of various psychosocial stressors and adaptations over time to minimize their impact. While physical environmental interventions would seem to logically function as a mediator to prevent stress proliferation, the nature of them, their timing and how they are delivered remains unknown. Additionally, the SPM does not adequately capture the intersection between stressors and strains within a dyad or family and how these systems navigate the illness experience over time.