Optimising tree arrangement policy in Australian small-scale residential settings

•Comprehensive review of urban planning policies on residential tree planting inclusion.•Identification of policy gaps regarding dominant tree planting configuration parameters.•Summarised tree arrangement technical guidelines in medium–density residential developments.•Understanding the asset of residential trees strengthening Australian suburban development policies.•Development of a general policy framework in arranging residential trees. Tree canopy loss in residential zones is a current Australian planning challenge in delivering liveable, heat–resilient urban developments. It is time for local governments to prioritise residential tree–planting programs on private properties. The best strategic practice is to endorse, optimise and protect a tree inclusion framework, especially for limited private green spaces, associating them with urban development policies. This paper examines residential tree inclusion opportunities in Australian design and planning policies at national and state levels, highlighting dominant tree planting configuration parameters. Then, it evaluates the Optimal Residential Tree arrangement (ORTa), combining site-specific tree policy requirements with building-integrated vegetation simulations for the Köppen Mediterranean climate classification. The ORTa offers technical guidelines, featuring three strategic outcomes based on property orientation, planting configuration, adequate deep soil level, and dwelling types. The paper also recommends a 4-step ORTa policy implementation process to ensure Local goverments’ success in greener medium-density development. This process calls for addressing prior policy deficiencies, endorse Local Government green assets alongside the existing scattered residential tree assets and ground soil areas, supporting collaboration among planning, building and community systems and mandating residential tree inclusion for a maximum energy efficient benefit. Implementing ORTa encourages biodiversity contribution and water-sensitive urban designs while achieving urban tree canopy targets.