A pergola is an outdoor room with cross rafters and no walls that provides a light, airy and inviting space to relax, dine or just admire. Pergolas are much larger than arbors and are generally freestanding, but can be attached to another building. You can also add lattice for more shade and to accommodate climbing vines. Because this structure can be freestanding, you won't need to make any complicated connections between the house or roof and the pergola, which is a definite advantage for do-it-yourself homeowners and the budget.