Some trees in Baulkham Hills need council approval before major pruning, and whether yours does depends on its species, trunk size and location. The Hills Shire Council sets these rules, and they can also apply to tree removal.
A property in a heritage or conservation area is more likely to face tighter controls. Two trees in the same street can be treated under different rules, so check before any cutting starts. You can read the current requirements on the Hills Shire Council website and in the NSW legislation register.
Trees Down Under provides council permit guidance as part of the job. During the free tree inspection, the tree arborist identifies the tree, measures the trunk and works out whether an application is needed. If it is, the team helps prepare it, including any arborist report the council asks for.
Work only begins once the right approvals are in place. That keeps the crown reduction lawful, protects you from fines, and avoids having to undo work that should never have started.