Urban planning and development is a field which unconsciously recognises the role of nonhuman actors in transforming the market environment – a process which often starts with exploring the constraints of sites or the cost implications of altered development forms. This paper explores some of those non-human actors central to planning and development at a fringe development site in Sydney, Australia. This paper draws upon actor-network theory to position non-human actors as vital to the construction and maintenance of any networked reality, not least residential development. In this reading non-humans represent central actors and intermediaries which circulate through planning and development networks. An actor-network theory framework provides an in-depth analysis of residential development and planning policy which facilitates the identification and tracing of actors/intermediaries which may otherwise be neglected, ignored or forgotten. Special attention is paid to the multiple ways in which non-human actors interact to facilitate the development of residential property and associated policy arrangements – focusing on endangered species and topography.