For a significant thrive towards sustainable development globally, sustainability attainment in affordable housing for low-income earners is fundamental. Identifying obstacles to sustainability attainment is primal to successful policy implementation. This study aims to identify critical barriers (CBs) to sustainable affordable housing (SAH) from an international perspective. To this end, 26 barriers were identified from comprehensive literature review and empirical questionnaire survey was conducted with 51 affordable housing experts from various countries around the world. Factor analysis on identified CBs revealed five components: green retrofit-related; land market-related; incentive-related; housing market-related and infrastructural-related barriers. Moreover, rank agreement analysis of the components showed high agreement levels on ‘incentive-related barriers’ and ‘housing market-related barriers’ between experts from developing and developed countries. The research findings are relevant to policy-makers and practitioners in adopting tactical measures for worldwide SAH. Besides, the identified CBs serve as recommended set of barriers for further empirical study to unearth local variations and context specific barriers to SAH in most countries.