ft.) The perfect starter size, with plenty of room for an outdoor furniture set. 12' X 16' Deck … ft.) A few more feet sets the scene with space for a dining table. https://blog.homedepot.com/how-to-build-a-diy-deck-on-a-budget 12' X 14' Deck design (168 sq. Select This Size. All Ideas; Why Trex® ... 12' X 12' Deck design (144 sq. Select This Size.