The paper depicts two main design approaches that are emanated from the ethics of social justice, i.e., the inclusive design and the sustainable design. Despite the significant advancement of these approaches in theory and practice, they haven't generated yet substantial design guidelines and regulations for public and/or residential settings that are pertinent to the real practice of design-related professionals, especially architects and interior designers. For this purpose the paper investigates /whether the 2 approaches are two sides of the same coin or are disparate set of ideas with totally separate agendas. It draws up the distinctiveness and disparity as well as the affiliation of their related concepts. The paper ascertains a tangible relationship that exists between the 2 approaches of social justice which enables an appropriate and unified field theory and practice. It also suggests an operable and inclusive agenda for design problem-solving based on the universality of design as an integrated dimension of social sustainability with the main purpose to ensure full participation and equal opportunity for every person in society. Finally, an exposure of some of the impediments that encumber the advancement of this agenda is sketched out.