The social equity of spatial compactness varies by context: evidence from Belfast, Glasgow and Liverpool

While compact urban development is widely promoted as a pathway to greater social equity, empirical evidence on the extent to which social equity is achieved remains inconclusive. To advance on this, we address three elements on compact urban development linked to social equity that have been little examined: (i) the conflation of compactness with density; (ii) the limited fine-scale analysis of compactness in relation to demographic patterns; and (iii) the underexplored relationship between demographic characteristics and urban compactness. On this basis, the study develops a multidimensional compactness measurement framework at a 500-m resolution, integrating physical, functional and socio-economic indicators. Based on this, multiscale geographically weighted regression (MGWR) models are applied to three UK cities—Belfast, Glasgow and Liverpool—to examine how demographic variables (ethnicity, employment, education, gender and age) relate to spatial compactness. The findings show that the demographic–compactness relationship is highly context dependent, varying across both locations and social groups. This highlights the need for equitable compact development strategies that are sensitive to contextual differences and responsive to the circumstances of diverse population groups.