People don't always realize the amount of options available when an old deck has rotted or become damaged and needs to be replaced. If you've always been happy with the old deck and it has suited your needs over the years, there's nothing wrong with building a new one exactly the same as the old one. However, if you've ever wanted a larger deck, extra support for a hot tub or outdoor kitchen, or any other upgrades, it's much easier to build the deck according to your needs rather than plan to add to it in the future.
Build a New Deck the Same as the Original
Building a new deck which is simply replacing the old one is arguably the simplest way to maintain a deck which is up to code and fills the needs you expect your deck to serve. Although the wood is rotted or damaged, your contractor can see and diagram what is there before the demolition process starts, and then rebuild the exact same thing. If you want the same deck built with upgraded materials, it's not a problem to use exotic wood or Trex decking to build what is essentially the same deck as you've always had, except with a nicer appearance and less maintenance requirements.
Design and Construct an Upgraded Deck with Specialty Features
If you spend a lot of time outdoors and use your deck on a regular basis, there are special features you can add to your deck to accommodate your hobbies or relaxation. A hot tub is a common luxury people like to add to their deck, and although it isn't a huge expense to add to the deck there has to be additional support to manage the weight of the water the tub holds. Likewise, grilling is a fun pastime for singles, couples, and families. Rather than buying new grills every few years a permanent outdoor kitchen can be built to accommodate such a lifestyle.
Planning for a Screened Porch
The screened porch allows you to enjoy the space without bugs or during a rainstorm. Any deck can have a roof built over it and be screened in at a later date, but if you know you're going to want such a project constructed you should discuss with your contractor how to build the deck for now in such a way to expedite the process when you decide to have it screened in.