A Complying Development Certificate may be issued for works including earthworks, retaining walls, drainage, protection of walls and protection of trees for land zoned R1, R2, R3, R4 or RU5 if the proposal meets all the relevant development standards.
You can use the Housing Code to check whether your proposal is complying development. The individual clause should be read in conjunction with all of Part 3.
If your proposal does not meet all of the standards you must lodge a Development Application.