Most Feng Shui schools ask which direction a house faces. Xuan Kong Da Gua asks which hexagram it sits on — and then which hexagram it faces, which is always the exact inverse of the first. This piece works through the mechanism with a real computed example: a house sitting north and facing south, the most conventional orientation in Chinese practice, produces hexagram 63 under hexagram 64 and rates as Challenging rather than ideal. The full five-rating table, the eight orientations our reading resolves to, and why turning the house around makes the reading worse rather than better.
Sitting and facing are one object, not two
Start with the pair, because everything else derives from it.
Facing is the direction the building presents outward — conventionally the side carrying the main entrance, the most open aspect, or the street frontage. Sitting is the direction directly behind it, 180° opposite, the side the building rests against. A house that faces south sits north. There is no third option and no independent variable: fix one and the other is determined.
Every directional Feng Shui system reads the pair rather than either bearing alone, because a building is defined by the axis it occupies. Where Xuan Kong Da Gua diverges is what it does with that axis next.
Each direction lands in one of the 24 Mountains — the 15° divisions of the compass that combine the Earthly Branches, eight Heavenly Stems and four trigrams — and each mountain belongs to a trigram. Sitting north in the Zi mountain gives you Kan (☵), Water. Facing south in the Wu mountain gives you Li (☲), Fire.
Three mountains share each trigram, so this step is where our reading settles its resolution: eight trigrams, eight sitting sectors of 45°, changing over at 22.5°, 67.5° and every 45° from there. Eight sitting hexagrams are reachable, each paired with its inverse. Classical practice subdivides the ring further and brings in the 20-year Period as a third input; we do not compute that, and this piece is about what we do compute.
Then the system does something the direction-only schools do not: it stacks the two trigrams.
The sitting hexagram and its exact inverse
A hexagram is two trigrams, one above the other. Xuan Kong Da Gua builds the house's pair like this:
- The sitting hexagram places the sitting trigram above and the facing trigram below.
- The facing hexagram swaps them — facing trigram above, sitting trigram below.
Which means the two are always exact inverses of one another. This is structural, not a happy accident of a particular orientation, and it is why the axis is read as one object.
Take the worked example — a house sitting north (Zi) and facing south (Wu), the most conventional orientation in Chinese practice. Our engine computes:
- Sitting hexagram: 63, After Completion (既濟) ䷾ — Kan over Li. Water above Fire: the classical image of a job finished, everything in its correct place, the kettle on the flame.
- Facing hexagram: 64, Before Completion (未濟) ䷿ — Li over Kan. Fire above Water: the flame rising away from what it was meant to heat, everything present but not yet joined.
The two most famous hexagrams in the I Ching — the pair the Book of Changes deliberately ends on — turn out to be the pair sitting under the most ordinary house orientation in China. The sitting side is completion. The facing side is the same six lines rearranged into not-yet.
The five ratings, and where they come from
The second thing the system computes from the pair is the elemental relationship between the two trigrams. There are exactly five possibilities, because there are five ways two of the five elements can relate.
| Relationship | Rating | What it describes |
|---|---|---|
| Facing produces sitting | Excellent | The outward direction nourishes the structure; support flows inward |
| Sitting produces facing | Good | The structure nourishes its outlook — productive, but it costs energy |
| Same element | Neutral | Harmony without exchange; nothing conflicts and nothing moves |
| Sitting controls facing | Challenging | The building dominates its own outlook; tension that can be managed |
| Facing controls sitting | Difficult | An outside force overwhelms the structure; stability is undermined |
Note the asymmetry, because it is the point. Producing in either direction is acceptable — best when it flows inward, still positive when it flows out. Controlling is a problem in either direction, but not equally: being controlled from outside is read as worse than controlling outward.
Now apply it to the north-sitting, south-facing house. Sitting is Kan, Water. Facing is Li, Fire. Water controls Fire — so the house rates Challenging, sitting controls facing.
This is worth sitting with, because the classical preference for a south-facing home is one of the strongest conventions in the whole tradition. Xuan Kong Da Gua does not endorse it on this axis. The convention rests on light, warmth, and shelter from the northern wind — real and sufficient reasons — and this calculation is measuring something else entirely.
Turning the house around makes it worse
The obvious response is to check the mirror: what happens to a house that sits south and faces north?
Computed: the same two hexagrams swap places — 64 sitting, 63 facing — and the rating becomes Difficult. Facing is now Kan, Water; sitting is Li, Fire; and Water controlling Fire now means the outside is controlling the structure.
Challenging became Difficult. The house did not change; only which end of the control relationship it occupies. This is the practical use of the five-row table above: it tells you that a controlling pair cannot be resolved by rotation, only by choosing a different axis.
What the eight sectors add
The pair is not the whole reading. Xuan Kong Da Gua also assigns a hexagram to each of the eight sectors inside the dwelling, by placing that sector's trigram above the sitting trigram. The sitting direction is therefore the constant that colours every room.
For our north-sitting house, the interior comes out as:
| Sector | Hexagram | Name | Image |
|---|---|---|---|
| N | 29 ䷜ | The Abysmal | Deep Water |
| NE | 4 ䷃ | Youthful Folly | Youthful Learning |
| E | 40 ䷧ | Deliverance | Liberation |
| SE | 59 ䷺ | Dispersion | Dissolution |
| S | 64 ䷿ | Before Completion | Transition |
| SW | 7 ䷆ | The Army | Disciplined Force |
| W | 47 ䷮ | Oppression | Exhaustion |
| NW | 6 ䷅ | Conflict | Inner Conflict |
Two houses on the same street with the same floor plan but a different sitting direction have eight different rooms, because the lower trigram of every sector changed. The sitting direction is not one detail among many — it is the key the whole interior is read in.
Getting the bearing right
The reading turns on which side of a boundary the house falls, and there are eight of them: 22.5°, 67.5°, 112.5° and so on. A bearing sitting well inside a sector tolerates a few degrees of error without moving. A bearing near a changeover does not — and a phone compass held next to a steel door frame, a fuse box or a car can be wrong by a good deal more than a few degrees.
So take it properly: outdoors, several metres from the structure, away from cars and metal, at least three times from different spots along the facing wall. If the readings disagree with each other, they are all suspect. And if the average lands within a couple of degrees of one of those changeovers, go back and take it again — that is the one case where the difference decides the answer.
This is the honest limit of any online reading, ours included. We can tell you what your bearing implies. We cannot tell you whether your bearing is right.
What it is and is not
Xuan Kong Da Gua reads the building — its axis, its pair, its sectors. It does not read you. There is no Kua number in any of the above, no birth data, no personal favourable directions; a house sitting north and facing south holds hexagrams 63 and 64 for everyone who has ever lived in it.
That makes it complementary to the personal direction systems rather than a competitor. Ba Zhai tells you which directions suit the person. Xuan Kong Da Gua tells you what the structure is doing. The reading gets interesting exactly where they disagree — a sector the person's Kua number likes, sitting under a hexagram of exhaustion.
Neither one is a verdict. Both are one axis of a building that also has to have windows in the right places, a door you can find in the dark, and a room where you actually want to sit.
Frequently asked questions
What are sitting and facing in Feng Shui?
Facing is the direction the building presents to the world — conventionally the side with the main entrance, the most open aspect, or the street. Sitting is the direction directly behind it, 180° opposite, the side the building rests against. Every directional Feng Shui system reads the pair, not either one alone, because a house is defined by the axis it occupies rather than by a single bearing.
How does Xuan Kong Da Gua differ from ordinary Feng Shui?
Ba Zhai reads the person: it takes your Kua number and tells you which of eight directions suit you, so two people in the same house get different answers. Xuan Kong Da Gua reads the building: it names the orientation as a pair of I Ching hexagrams and assesses the elemental relationship between them, and everyone living there inherits the same diagnosis. The difference is what is being measured, not how finely — our reading resolves the compass to the same eight orientations Ba Zhai uses.
What is the mountain ring?
The ring of a Chinese geomantic compass on which hexagrams are laid out against directions. Our reading takes the bearing to its 24-Mountain position, reduces that to the mountain trigram, and builds the sitting and facing hexagrams by stacking the sitting and facing trigrams in each order. Because a trigram covers three mountains, the pair resolves to eight orientations of 45° — eight sitting hexagrams, each with its inverse as the facing.
Why is a house sitting north and facing south rated Challenging?
Sitting north puts the house on the Kan trigram, which is Water; facing south puts the facing on Li, which is Fire. Water controls Fire in the five-element cycle, so the sitting energy dominates the facing — a controlling relationship rather than a nourishing one. It is not a verdict on the house; it is one axis of assessment, and the classical preference for a south-facing home rests on light, warmth and shelter from northern wind rather than on this calculation.
Is the facing hexagram just the sitting hexagram upside down?
Yes, and this is structural rather than coincidental. The sitting hexagram is built with the sitting trigram above the facing trigram; the facing hexagram swaps them. Every house therefore holds a matched pair of hexagrams that are each other exact inverse — which is why the sitting/facing axis is read as one object rather than two readings.
Does turning the house around improve the reading?
Not necessarily, and often the reverse. A house sitting north and facing south rates Challenging (sitting controls facing); the same structure turned to sit south and face north rates Difficult (facing controls sitting), because an outside force overwhelming the building is read as worse than the building dominating its own outlook. The two orientations are not mirror images in quality — the direction of the control matters.
Do I need my exact compass bearing?
You need a bearing good enough to place the house on the right side of a boundary. The eight hexagram sectors change over at 22.5°, 67.5° and every 45° after that, so a bearing sitting comfortably inside a sector will survive a few degrees of error, and a bearing near a changeover will not. A phone compass held next to a steel door frame can be off by considerably more than a few degrees, which is why the reading is worth taking properly: outdoors, several metres clear of the structure, away from cars and metal, more than once. If your bearing lands close to one of those changeovers, that is exactly when to go back and check it.