A deck is an open, flat section of flooring that extends out from your Sim's home. In "The Sims 3," all decks start with a foundation and the house to which they attach must also rest on a foundation so it meets the same horizontal level as the deck. When you build your Sim's house, if you think you want a deck at some point, it's important to place a foundation before you build the walls of the home. "The Sims 3" Building Mode tool palette includes two styles of deck foundation, red brick or diagonal lattice, as well as several railings and stair styles.
Click the "Build Mode" icon on "The Sims 3" control panel. The icon is a picture of a hand saw crossed with a paint roller.
Hover your mouse over the different build category symbols to see their names; click the one called "Platforms, Decks & Foundations."
Click the button for the brick foundation or the lattice deck. Either can be used to make a deck.
Click and drag over the ground where you want the deck to appear. The cost of the construction displays as you drag, so you can adjust the size based on your Sim family's funds.
Click the "back arrow" symbol to return to the main "Build" screen; click the symbol for the "Fences" category.
Click on a fence style, and then click and drag on the edge of your deck to add railings. Leave an opening for stairs on at least one side of the deck.
Click the "back arrow" symbol to return to the main "Build" screen and click the symbol for the "Stairs, Railings & Elevators" category.
Click on a stair style and stair width, and then click on the edge of the deck where you want the stairs to go.
Click the "Live Mode" button above the "Build Mode" button on the control panel to return to your game and let your Sims use their new deck.
Click the "Flooring" category under "Build Mode" to change the deck's default flooring style to a different wood pattern, material or colour. Click the "Buy Mode" button between the "Live Mode" and "Build Mode" buttons to access "The Sims 3" objects store. Here you can purchase deck furniture, grills and other outdoor items to place on your Sim's new deck.
If you are playing an active family lot in "The Sims 3" and adding a deck to their existing home, the construction takes money from the family coffer for every change you make. Check that your family has enough funds to complete the job before you begin. An 8 x 8 deck costs about 220 Simoleons. Fences start at 10 Simoleons a section. If you are building a deck on a home in an unused lot, the cost of the deck is added to the purchase price for the lot.