It really depends on what you are looking to do. Each council has its own set of rules and standards. These are commonly referred to as Local Environment Plans and Development Control Plans. Your land may also have specific controls such as bushfire requirements, easements and protection overlays that need to be taken into account in the design. If you are looking make a modification to a home, add to the floor area, or undertake new building work, you will most likely need council permission. Some projects can be designed to comply with all council codes and this will streamline the approval process in some cases. Feel free to contact me to discuss the specific rules and restrictions that pertain to your land.