Population aging requires residential environments that go beyond basic accessibility. This study theorizes and validates the Accessibility Gap (the divergence between regulatory compliance and the functional lived experience of older adults) using a Multi-Criteria Decision Analysis (MCDA) tool. The research uses a weighted linear aggregation model based on user-centered design and the International Classification of Functioning, Disability, and Health (ICF). Thirty dwellings—apartments, single-story, and two-story houses—were evaluated in Chile’s Metropolitan Region. The model applies 40 indicators, normalized on a 0–100% scale across six dimensions, and weighted by older adults and caregivers. Results reveal fragmented accessibility gap: basic features often meet standards; yet important deficits remain in highly prioritized areas—autonomy, safety, and communication. The Global Performance Index (GPI) identifies “accessibility gaps” that traditional assessments miss. By combining objective metrics with subjective experiences, this study delivers a replicable, evidence-based framework. It shows that specific design choices, rather than architectural configuration, better support functional independence. The MCDA approach provides a robust tool for guiding housing rehabilitation and public policies that support aging in place and ensure homes meet the needs of an aging population.
Valderrama-Ulloa et al. (2026) studied this question.