What are the necessary steps to build a 12x20 deck in my backyard?

To build a 12x20 deck in your backyard, follow these steps:

1. Obtain necessary permits and check local building codes.
2. Plan the layout and design of the deck.
3. Gather materials such as lumber, concrete, and hardware.
4. Prepare the site by leveling the ground and installing footings.
5. Build the frame and secure it with joist hangers.
6. Install decking boards and railings.
7. Finish with staining or sealing the deck for protection.