Cities have become more fragmented due to the increasing urbanisation of many parts of the world. There is more inequality and a growing complexity of social life in cities that leads to social exclusion and increasing social differentiation. This study approaches social inclusivity within the context of universal urban design and defines it as a vehicle for promoting human wellbeing, environmental wholeness and principles of participatory democracy. Mat urbanism - an urban form concept that is more organic and fluid than other urban forms and models - is proposed, alongside a universal design approach, to achieve the goals of sustainable communities and enhance quality of life. The relationship of mat urbanism to the features of high-quality environments and sustainable developments is questioned and illustrated with simple diagrams. The paper concludes with the importance of universally designed sets of regulatory practices regarding sustainable architecture and urban development - from individual buildings to the district and city-scale level. The contribution of this study is not only to explore the potentials of Smithson's configurations theoretically but also to open new means through which towns and cities can be planned in the future in order to promote social inclusivity, environmental responsiveness, sustainability and universal urban design.