There’s nothing like having a great deck to enjoy relaxing and entertaining outside. There are many materials to choose from. Many decks are constructed using pressure treated yellow pine which holds up well against the moisture. In full sun or for reduced maintenance you may want to consider choosing a composite material. Also you should consider changing the existing grade if it doesn’t drain properly. Cost figures mentioned are based on adding a deck with footings and posts to 48” below grade, PT framing, single to two levels, railings, decking fastened with screws or hidden fasteners, properly flashed where attached to the house, lattice below and stairs to the ground.