Sand is an easy metaphor for time, and a pretty obvious one, too, but that doesn't mean a film can't succeed despite milking the metaphor for all its worth. Stories set exclusively in the desert have a lot of sand to work with, after all, and not much else.The House of Sand, which takes place in the area of northern Brazil now known as Lençóis Maranhenses National Park, an area that isn't a desert but has many of the characteristics of one, shows that living amidst sand and more sand can be so monotonous that perhaps counting the grains to pass the time is sometimes all one has.
Of course, no one actually counts sand in the film, but the grains are used to show time passing, whether in such a blatant shot as the close-up of sand trickling down the side of a dune or in more narrative-essential imagery like the shifting appearance of the landscape. Fortunately the film doesn't actually consist of people sitting around waiting for the scenery to change, either. Instead, The House of Sand plays out over the course of almost sixty years, and its progression of time is primarily, and more significantly, marked by man's advancements in science and technology, with their ability to seemingly make the world, and the universe, smaller.