The distribution of green walls and green roofs throughout Australia: Do policy instruments influence the frequency of projects?

•Green wall and green roof (GWGR) projects were identified across Australia.•Presence, types, and absence of local government GWGR policies were explored.•The presence of local governmental policies promoted the uptake of GWGR green infrastructure projects.•Australia can improve the current policies, facilitating enhanced uptake in GWGR projects.