Affordable housing, as a fundamental pillar of spatial justice and urban sustainability, has emerged as a critical challenge for urban planning systems globally in recent decades. The rapid pace of urbanization, continuous rise in land and housing prices, escalating social inequalities, and the consequences of climate change have made access to adequate housing increasingly difficult for low-income groups. In this context, the challenge extends beyond the mere quantitative provision of housing units; the spatial distribution of these units and their alignment with sustainable development principles are of decisive importance. This study aims to analyze the knowledge structure, identify thematic clusters, and examine the conceptual evolution of research related to the spatial assessment of affordable housing based on sustainable development indicators. The research methodology employs a bibliometric analysis of scientific publications indexed in the Web of Science and Lens databases between 2021 and 2026. Following data screening, selected articles were analyzed using VOSviewer and Bibliometrix. Key metrics evaluated include co-authorship, co-occurrence, and co-citation networks; longitudinal trends in publications and citations; source distribution based on Bradford’s Law; author productivity patterns according to Lotka’s Law; and conceptual and thematic mapping. The findings indicate that this field has reached a stage of scientific maturity, characterized by a highly cohesive knowledge structure. While “sustainability” and “urban planning” have become established as central cores, themes such as “urban governance,” “resilience,” “social justice,” and, notably, “public health” are emerging as influential trends shaping future paradigms. The results suggest that the development of affordable housing requires an integrated, place-based approach that synthesizes physical, social, and environmental indicators within multi-criteria assessment models. By mapping the knowledge structure, this study provides an analytical foundation for enhancing sustainable spatial allocation models and spatial policy-making.