Symmetry of Layout
In China, the construction of palaces, temples and ordinary houses generally forms a unit, or building complex. Any given structure within the building complex occupies a place and a function within the whole - indeed, the external function of a building determines its relative placement within the hierarchical whole - while the inner organization, or compartmentalization, of any given structure follows the inherent logic of the internal functions of the building. Most of the individual structures within such a building complex follow the strict principle of a center axis surrounded by symmetrical wings, such that the overall appearance of the individual structure is one of perfect symmetry. This type of axis-centered, symmetrical building principle, combined with a hierarchical layout for the entire building complex, reflects the aesthetic standards of balance and harmony of ancient China's Taoist past (feng shui is of course the term that comes to mind – for an explanation of the principles of feng shui, click here).
The Siheyuan Compound
The Siheyuan compound is almost as old as China itself, dating back to the Western Zhou (BCE 1027-771) Dynasty. It is found in every corner of China, and was the basis for all subsequent Chinese building art – whether official or vernacular – and for good reason: with its walls on all four sides, it offered protection both from intruders, whether animal or man, and from the wind (and windborne dust, snow, etc.); it offered ample space for a hierarchy of different buildings with different functions, from the utilitarian to the social, the latter reflecting the social status of the individual; it offered space for smaller, more intimate gardens, including kitchen gardens where vegetables could be grown, as well as space for the larger, communal, center couryard. In short, the Siheyuan compound met all the needs of a feudal lord, a bourgeois merchant, or an extended Chinese family in the way of a private residence, where privacy could be enjoyed when desired, and where communality could be pursued when broader social interaction was the order of the day.
The Siheyuan compound is especially associated with the city of Beijing. This is surely in part owing to the fact that the city which was eventually renamed Beijing was a completely new, from-scratch city, built on the orders of Genghis Khan's grandson, Kublai Khan, after the capital city of the Jin (CE 1115-1234) Dynasty had been razed to the ground in CE 1215 by Genghis Khan and his Mongol warriors. Kublai Khan, who became the first Yuan (CE 1279-1368) Dynasty emperor (he served from CE 1260-1294), drew on the expertise of a certain Han Chinese official, Liu Bingzhong, who had in the meantime become a monk, to serve as an adviser without portfolio, as it were, to the emperor (in this regard, Kublai Khan was not unlike many brilliant leaders both before and after his time – eg., Alexander the Great and Napoleon – who did not shy away from drawing on the expertise of talented individuals, irrespective of their ethnic origins).
Tasked with building a new capital city from scratch, Liu Bingzhong designed a perfectly symmetrical north-south, east-west grid as the layout for the new capital city, which was named Khanbaliq (aka Dadu), later to be renamed Beiping (in CE 1368) during the reign (CE 1368-1398) of the first Ming (CE 1368-1644) Dynasty emperor, the Hongwu Emperor, then renamed Beijing ("Peking" in the language of Western colonial powers) during the reign (CE 1402-1424) of the Yongle Emperor of the Ming Dynasty. Liu Bingzhong's quadrangular grid form for the new capital city went hand-in-glove with the quadrangular Siheyuan building style – indeed, it is quite likely that Liu Bingzhong had the quadrangular Siheyuan building compound in mind when he decided to lay out the new capital city in quadrangular form.
When the ethnic Mongol Yuan Dynasty was later replaced by the Han Chinese Ming Dynasty, the new rulers obliterated as much of the Mongol influence as possible, destroying much Mongol architecture in the capital city especially, though the overall layout of the city could not be changed without razing Dadu to the ground, which was unthinkable. Dadu's Siheyuan compounds were of course as genuinely Han Chinese as apple pie is claimed to be genuinely American, so most of Dadu cum Beijing went free of the Ming Dynasty cultural revenge against the Yuan Dynasty rulers.
Most attempts at describing a Siheyuan compound fall miserably short of conveying an intelligible image, via words, of how such a compound is actually laid out. It really is true that a picture (or diagram) is worth a thousand words in this case! The following is an attempt to give a brief verbal description of the Siheyuan compound, in the hope that the reader will finally "get it" the next time s/he runs across the term.
First of all, a Siheyuan compound comes in multiples of "jin", which, without getting too deep into semantics, the reader may take as a shorthand expression for "main courtyard" (the Siheyuan compound has, besides its main, or common, courtyard(s), smaller courtyards/ private gardens, usually one in each corner of a 1-jin Siheyuan compound, but this gets more complicated with 2-jin or more Siheyuan compound). A 1-jin Siheyuan compound has one main, roughly-centered courtyard.
So, to begin at the beginning, a Siheyuan compound is a square or a rectangle with buildings on all four sides. Think of these building-populated sides as "wings" of the compound (one wing corresponding to each compass direction). The entranceway wing and the wing opposite the entranceway wing have buildings/ structures that usually completely "wall off" the compound on those sides, except, of course, for the entranceway itself, which is wide enough to be practical (allows carts of a certain size to pass through), but no more (they are not generally broad portals offering breathtaking vistas, unless the compound itself is of palatial dimensions, and here we are speaking strictly of private dwellings). For the sake of practicality, call these two wings the south (entranceway) and north wings.
The buildings of the corresponding east and west wings do not "wall off" the compound on those sides. Instead, there is a gap between the north and south ends of each of these wings, and it is in this gap where one finds the smaller, "private" (as opposed to "common") courtyards/ private gardens. In actuality, there might be a private courtyard immediately behind the entire front (south) wing, with a number of north-south partitions to it, broken only by the entranceway itself, which is always to one side of the entranceway wing, rather than being in the center (as regards private dwelling compounds in any case). In our example, the entranceway is on the right side of the south wing, leaving space enough to the right of this for the private garden in the southeast corner of the compound.
Assuming that the entranceway is to the right side of the entranceway (south) wing, then there will be an extra, inside "wing" of structures that run parallel to, and just in front of (seen from the interior of the common courtyard) the east wing, and with a narrow gap between the two east-side wings that can serve as private, partitioned gardens to the dwellings on the outside east wing. The purpose of this inside eastern wing is to serve as a corridor/ "hallway" (it may only be roofed), allowing access to the rest of the buildings of the compound.
So, to recap: one has the south wing with its entranceway typically on the right; one has the double wing on the east side (on the right side when the viewer faces north), the inner wing of which serves as a corridor connecting the entranceway with the rest of the compound, and the outer wing of which has gaps at either end to provide space for the corner courtyards/ private gardens; one has the north wing whose buildings wall off completely the north side; and finally, one has the west wing which, like the outer wing of the east side, has gaps at either end to provide space for the corner courtyards/ private gardens.
A simple, 1-jin Siheyuan compound may either be square or rectangular. However, a 2- or 3-jin Siheyuan compound is always rectangular. This is because what distinguishes a 2-jin compound (from the following description, the reader can extrapolate to the 3-jin compound) from a 1-jin compound is the fact that there is an extra, center wing composed of east-west buildings that divide the compound into two equal halves, roughly, leaving two main, or common, courtyards, one south of the center wing and one north of it. The wing that faces the entranceway wing (the wing opposite the south wing) of a 2-jin Siheyuan compound is not the north wing, as in a 1-jin Siheyuan compound, but the center wing. With a 3-jin Siheyuan compound, one has three common courtyards.
There can be variations on the basic setup described above, such as a double wing on the north side, such that the corridor/ "hallway" describes an upside-down-and-reversed "L", but the above description is the basic layout of a typical Siheyuan compound.