This paper aims to explore the idea and methods of rewilding architecture. The notion of rewilding was based on pastoralism movement, which aims to reconnect humans with nature through reintroduction of wildlife. This study explores the architectural design methods of rewilding, through investigating looseness and animate as mechanisms that shift how humans may see and treat nature. This paper investigates ten case studies of rewilding architecture and annotates the mechanisms of looseness and animate which occur in different categorizations of human and natural activities. Based on the reading on these case studies, the study concludes on design methods that define rewilding architecture based on looseness and animating characteristics. Rewilding methods aim for the development of connections that allow cycles of natures, extensions that drive growth of natures, and variations that produce multiple layers of possibilities of natural lives in the internal and external existence of architectural space. Such methods demonstrate the potential of architecture that no longer wishes to control nature, but letting it animate and develop loosely in driving its spatiality.