Welcome to the Bunnings Workshop community. It's wonderful to have you join us, and thank you for sharing your question about replacing your gazebo.
If you are planning on building a simple pergola like structure, would it be possible for you to post a photo of the current location where you plan to build it? Can I also please ask for dimensions for the structure you are planning to build? I've linked some discussions about pergolas that are attached to the house.
Here are some fantastic Pergola structures that our Workshop members have shared:
The size of the timber to be used is often linked to the size of the structure you are planning to build. A timber structure called a waling plate is generally attached to the rafters of the house. The rafters of the pergola are then attached to the waling plate.
If you are using treated pine, it is possible to stain and varnish it to your desired colour.
Please remember to use personal protection such as gloves, goggles and a dust mask when working on your pergola.
If you need further assistance, please let us know.