Depending on where you're building your decking, you may need to build in a certain way, choose special materials or restrict your plans. Bushfire and cyclone prone areas in particular require special building techniques and materials. Likewise, the height of your deck will also have a significant impact on how it's built.
Make sure you understand the regulations that apply in your area, to your decking plans.
Depending on the type of pergola you intend to build, you may need to apply for specific permission to build. Find out when you're likely to need permission, and how to go about submitting an application.
Decks constructed beyond a certain height need to be built with handrails. The construction of the handrails is also regulated, to further lower the risk of an accident. See what's required for your decks.
Regulations apply in bushfire prone areas which may affect how you're allowed to build a pergola. Find out what regulations apply, and how they affect your plans.
If you're planning on building a pergola in a cyclone prone part of Australia, it will need to comply with the cyclone code. Find out what sorts of cyclone proofing measures are required.