Presenting the engagement of immigrants, their descendants and native Norwegians with Norwegian Constitution Day celebrations, this chapter discusses how people de facto change elements of national culture through their micro practices. It explores data collected between 2013 and 2020 during the Norwegian Constitution Day celebrations in the area of Drammen municipality, Norway. The analysis is supported theoretically by the concept of the third space. Additionally, I use the concept of heritage in becoming to problematise the dynamic between a genealogical model of national heritage and its interpretation performed by people in relation to the spatial, cultural and structural circumstances in which they live. The chapter argues that the individual patterns of Norwegian Constitution Day celebrations exercised by immigrant minorities constitute a third space. Immigrants de facto change the Norwegian national heritage. Subsequently, I analyse the extent to which this change is reflected at the level of mainstream celebrations and the ways in which it is mediated by agents of non-change. Moreover, the chapter discusses the problem of identity reductionism and the reification of ethnicity present in multicultural societies, arguing that the performances of the actors within the third space may serve as means of resistance against “groupism”.