There are several schools within feng shui, and among them xuankong feng shui stands out as a more three-dimensional system, in that it reckons not only with space but with time as well. The feng shui we usually picture deals with relatively fixed spatial conditions—the formation of mountains and water, the good or ill of directions. Xuankong feng shui, however, adds one more question: even at the same spot, might the energy not change as time passes? In this piece, rather than treating xuankong feng shui in depth, the aim is to look gently at its broad outline and idea, enough to say that such a school exists.
The single greatest feature of xuankong feng shui is a concept of time that holds the energy of the land to shift in fixed cycles. Traditionally this flow is called an "era", and roughly twenty years are taken as one segment. As one era passes and gives way to the next, which direction flourishes and which wanes is said to change. So even for the same house, a spot read as favorable in one period may be read differently in another. Space is regarded not as a fixed picture but as a living flow that slowly changes shape with time.
At the foundation of this system lies the nine-palace chart, which derives from an old diagram called the Luoshu. The nine-palace chart is a frame dividing a square into nine cells, made of one central cell and the eight surrounding directions. Into it the nine numbers from one to nine take their places, and in xuankong feng shui each of these numbers is seen not as a mere figure but as a star bearing a character of its own. And these stars are held not to stay in one place but to move from cell to cell according to fixed rules. In the sense that the stars fly about, this is called the flying stars.
In practice, those who work with xuankong feng shui examine together the year in which a building or grave was made and its sitting and facing—that is, which way the building has its back to and which way it looks toward. On the basis of these two pieces of information, they draw up a kind of layout chart called a flying-star plate, within which several stars come to overlap in each direction. Reading the combinations of stars thus arranged—gauging which direction is favorable for wealth and which calls for caution, which seat may affect health or relationships—is the basic work of xuankong feng shui. Even for houses built in the same year, a different facing yields a different flying-star plate, so the reading too differs from house to house.
There is, however, one point to make clear here. Xuankong feng shui is a highly specialized and complex system that requires reading together the combinations of the several stars placed at the center and the eight directions. When the character of each star, the harmony of stars meeting one another, and on top of that the era of time are all layered together, the number of cases grows very great indeed. So it is a field that even those who have built up long study and experience handle with care, and its whole cannot possibly be mastered through a single short piece. What the beginner needs is not to memorize every rule, but first to understand that such an idea and framework exist.
The purpose of this piece is therefore clear. Rather than receiving xuankong feng shui as some absolute verdict of fortune and misfortune, let us regard it as one branch of the intricate reasoning of people of old who sought to read the flow of the world by adding time to space. The thought that the land, like a person, changes its aspect with the seasons, and the effort to draw that change in the language of numbers and directions, are in themselves a fascinating cultural heritage. Deeper study may be left to specialized sources and long practice, but for us it is enough to set out from the understanding that such a school exists and that it sought to read the world in this way.