This project investigates whether home modifications reduce disability and related outcomes among older adults amid global population ageing. Addressing methodological weaknesses in prior research, it applies innovative analytic strategies to longitudinal household data from over 50,000 older adults in 13 countries, incorporating spouse/partner information to account for selection processes. Complementary Hong Kong–based analyses examine inequalities in access to home modifications by housing tenure and impacts on caregivers. Findings will inform evidence-based housing and social care policies, supporting occupational therapists, housing authorities, and governments in promoting ageing in place and reducing disability-related burdens.