In this essay, the differences between the two movements are not discussed, and the term SGNU is used for both smart growth and new urbanism. One thing that needs to be made clear is that SGNU emerged to join the debate between postmodernism and modernism, but is not a follower of either. As highlighted by Beauregard, RA (2002), SGNU rejects the relativism of the former and the sterility of the latter. The following discussion is necessary and essential to understanding the social justice concerns related to SGNU. On the one hand, SGNU is apparently not a fan of postmodernism. Concerned by numerous urban planners and architects, SGNU has been established as a theory for pursuing good urban form or what our metropolitan areas should look like (Ellis, C., 2002). This type of instrumental rationality of normative planning is rejected by postmodernism. An example is the concept of well-defined boundaries in SGNU. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay. Specifically, SGNU defines centers, network, space, and community based on clearly delineated boundaries while postmodernism views all boundaries, even physical ones, as “fuzzy and contested” (Zerubavel, 1991). Furthermore, the implementation side of SGNU is rejected by postmodernists. Specifically, a typical SGNU implementation process begins with a public charrette, a series of workshops where local people gather to discuss what kind of places they expect and how they would prefer to live. The goal is to find a shared understanding and consensus on the desired urban form, transportation or built environment. However, postmodernists reject this approach to forming consensus. From their point of view, consensus is based on shared values ​​and therefore merges difference (Harvey, 1997). A more extreme view of postmodernists is that individuals' views are not commensurable (Beauregard, R.A., 2002), particularly when they come from different cultures/races. On the other hand, in terms of planning and design thinking, SGNU is not a defense of modernism. Specifically, SGNU did not follow the dominant theory of modernism, also known as the International Style (Relph, 1987). Instead, it rejects modernism's insensitivity to human scale, but encourages mixed-use, pedestrian-friendly, transit-friendly urban environments. Indeed, SGNU's main tools and objectives reflect a common consideration: sustainable development emerged as a wave of counter-planning theories of modernism. According to Campbell, S.D. (2013), sustainable development in planning theory can be defined as “a broad set of principles and corresponding planning policies to bring urban economies and local land development into closer alignment with long-term constraints landscape term to support urban settlements, absorb waste from human activities and allow non-human flora and fauna to survive and thrive". From the perspective of urban and transport planners, urban sprawl can be treated as the “ waste of human activities” and in this way the SGNU can be classified in the wave of sustainable development. Note that another wave of planning theories – social justice – emerged around a similar period against modernism (Beauregard, 2002). Each of these two trends has its own distinct histories and trajectories, deeply rooted in disparate ideologies, priorities and institutions (Campbell, 2013). The two separate conversations were often overheard from each other, but it was not easy to merge them.