Instructions
Launch the Sim 2 game and click the house you want to modify.
Click the "Build" icon, then click "Foundations and Decks."
Click the edge of the deck to modify and hold down the "Ctrl" key.
Drag the cursor along the edges of the deck. Release the Ctrl" key to delete the current deck lattice.
Click the "Foundations and Deck" icon and select a deck lattice to use.
Left-click while tracing the edges of the foundation where the deck originally was to change to the new deck lattice. Release the button to complete the new deck lattice.
Click the "Save" icon to keep the new lattice.