The room pages on this site keep arriving at the same question. What Is Feng Shui closes its survey of the compass school by naming its two best-known methods — the eight mansions (八宅, bazhai) and the flying stars — and leaving both unopened. The bedroom page points the headboard’s direction question at “the occupant’s mingua”; the home office page parks the desk-facing question at the same term; the front door page defers the door’s favorable sector to “the resident’s own kua number.” Three pages, one deferral: this page is where the deferral ends.
Eight mansions feng shui is the compass-school method that pairs each person with a ming gua (命卦, “fate trigram”) — a number from 1 to 9 computed from the birth year, each number standing for one trigram — and sorts both people and houses into an east group and a west group. From the pairing it reads, for each person, four favorable directions and four unfavorable ones. This page covers the machinery end to end: how to compute your trigram, the group tables, how a house joins a group, the eight stars and what each is said to govern, how the room pages’ direction questions plug into it, and where the whole method honestly sits — ending with a five-minute check.
What is eight mansions?#
The core move of eight mansions is matching person to house: compute a personal trigram from the birth year and gender, assign the person to the east or the west group; read the house’s sitting direction, assign the house to the east or the west group; then judge the fit by whether the two groups match. Same group, the pairing is said to be in step; different groups, out of step — and the remedies are local ones (door, bed, stove), not a moving van. The method is fully formed by the Qing dynasty; the title most often cited for it is the Bazhai Mingjing (《八宅明镜》, “Bright Mirror of the Eight Mansions”), a book whose authorship attribution is traditional and whose text circulated in the last two imperial centuries.
In English-language feng shui writing the same machinery travels under two names: the fate trigram or ming gua, and the kua number — same number, same formulas, same tables. What the number buys you is the one thing the universal direction chart cannot: it makes the reading personal. The universal bagua map tells every reader the same thing about the same direction; eight mansions tells reader A and reader B different things, because A and B were born in different years.
One framing note before the formulas. Everything on this page is a traditional reading — a system of correspondences the tradition developed and its books record — and not a prediction. The stars “govern” careers and health in the way the tradition’s rubric says they do; the practical value for a modern reader is the same as the other room pages’: a structured checklist that makes you look at the plan of your home once, carefully.
How to compute your ming gua#
The number is what feng shui writing asks for when it asks how to find your feng shui number (or your kua number), and the computation is two formulas, one for each sex:
- Men — sum the four digits of the birth year down to a single digit (if a step lands on two digits, add them once more), then subtract that digit from 11.
- Women — sum the four digits of the birth year the same way, then add 4.
- If either result runs past 9, sum its digits once more down to a single digit.
- A result of 5 is reassigned: a man’s 5 is read as 2, a woman’s 5 is read as 8.
Worked examples, chosen to show the moving parts. For anyone born in 1985: the year sums 1+9+8+5 = 23, and 2+3 = 5. A man: 11 − 5 = 6, the Qian trigram, west group. A woman: 5 + 4 = 9, the Li trigram, east group. Same year, same arithmetic, opposite groups — the sex of the person is a full participant in the method, not a footnote to it. For a woman born in 1999: 1+9+9+9 = 28, 2+8 = 10, 1+0 = 1; then 1 + 4 = 5, which the rule reassigns as 8, Gen, west group — the branch that catches most people who try the formula once and distrust the answer.
Two cautions the method’s own books make. First, the year in question is the stem-branch year, whose boundary is the Beginning of Spring (立春, lichun) rather than January 1 or the lunar new year festival — anyone born within a few days of that boundary should check which year is meant before trusting a single-digit answer; the stems and branches page holds that calendar. Second, the quick-lookup tables that circulate most widely sum only the last two digits of the year and switch their coefficients at the year 2000; that shortcut agrees with the full four-digit sum in most years, and where the two disagree, the four-digit computation is the one the method’s tables are built on. The shortcut is a convenience of print; the full sum is the reference.
The east and west groups#
Each number stands for one trigram, and each trigram carries the compass direction it governs in the post-heaven arrangement. The eight mansions inherit that seating wholesale, then split it down the middle:
| Number | Trigram | Direction | Group |
|---|---|---|---|
| 1 | Kan 坎 | North | East |
| 2 | Kun 坤 | Southwest | West |
| 3 | Zhen 震 | East | East |
| 4 | Xun 巽 | Southeast | East |
| 6 | Qian 乾 | Northwest | West |
| 7 | Dui 兑 | West | West |
| 8 | Gen 艮 | Northeast | West |
| 9 | Li 离 | South | East |
The number 5 never appears as a ming gua — the reassignment rule in the last section is precisely what removes it (a man’s 5 becomes 2, Kun; a woman’s 5 becomes 8, Gen).
The direction each trigram governs is not the method’s own invention; it is the classical seating, recorded in the Shuogua (《说卦传》, “Discussion of the Trigrams”), the ancient commentary on the Book of Changes. That chapter seats the eight by one round of a single figure: 帝出乎震,齐乎巽,相见乎离,致役乎坤,说言乎兑,战乎乾,劳乎坎,成言乎艮 — “the sovereign issues forth from Zhen, is made even in Xun, is seen in Li, takes service in Kun, speaks with joy in Dui, joins battle in Qian, toils in Kan, and completes his word in Gen.” Each direction earns its own verb — the eight are stations on one round, not eight free-floating labels — and the seating that round fixes (Zhen east, Xun southeast, Li south, Kun southwest, Dui west, Qian northwest, Kan north, Gen northeast) is the one eight mansions computes on. The eight trigrams page holds the symbols themselves and the two arrangements.
Why the split falls where it does: the groups run on the generating cycle of the five elements. The east group is a chain — Kan’s water feeds Zhen’s and Xun’s wood, and wood feeds Li’s fire. The west group is a chain of its own — Kun’s and Gen’s earth feeds Qian’s and Dui’s metal. Within a group, element feeds element; across the groups, west’s metal cuts east’s wood. That is the whole of the “east person, east house” logic: same group means the elements run in each other’s favor, cross-group means one side’s element works against the other’s.
East and west houses#
A house joins a group the same way a person does — by its trigram — except that a house’s trigram is read from its sitting direction, the direction its back rests against:
- East houses — sitting north facing south (a Kan house), sitting south facing north (Li), sitting east facing west (Zhen), sitting southeast facing northwest (Xun).
- West houses — sitting southwest facing northeast (a Kun house), sitting northwest facing southeast (Qian), sitting west facing east (Dui), sitting northeast facing southwest (Gen).
The core advice of the whole method fits in one line: an east-group person in an east-group house, a west-group person in a west-group house. The pairing in step is the state the method aims at; the pairing out of step is not a verdict on the house — the traditional remedies are local ones, the door’s direction, the bed’s and the stove’s placement, taken up in the next two sections. The one direction of the house you can change without a demolition is the door’s, and the front door page’s own order — what the door opens onto first, which way it faces second — holds whatever your group.
The eight stars: four auspicious directions, four not#
With your trigram fixed, the method spreads one more layer: each of the eight compass directions around you — not around the house — is assigned one of eight “wandering stars” (游星), four favorable, four not:
| Star | Rank | Said to govern |
|---|---|---|
| Sheng Qi 生气 (“generation”) | first of the four | endeavor and income |
| Tian Yi 天医 (“heavenly physician”) | second | health |
| Yan Nian 延年 (“extended years”) | third | marriage, company, long life |
| Fu Wei 伏位 (“stability at home”) | fourth, mildest | steady rest at one’s own place |
| Huo Hai 祸害 (“mishap”) | mildest of the four | quarrels, small frictions |
| Liu Sha 六煞 (“six clashes”) | next | entanglements and disputes |
| Wu Gui 五鬼 (“five ghosts”) | next | losses and standings gone wrong |
| Jue Ming 绝命 (“life cut off”) | harshest | the one direction to keep the bed off |
Which direction carries which star is not a fixed chart shared by everyone — that is the second thing the method personalizes. The stars are derived from your own trigram, one line change at a time, so each of the eight trigrams has its own spread of the eight stars over the eight directions; two east-group people (a Kan person and a Li person, say) do not share their four favorable directions. The universal map says what a direction is; the star spread says what that direction is for you — and the star-spread table for your own trigram is what the fuller eight-mansions books are mostly made of. What each star governs is the tradition’s rubric, recorded as its books record it; it is a reading of directions, not a prediction about them.
How to use it#
The working order, as the method itself runs it:
- Compute your ming gua — the two formulas above, the number, the trigram, the group.
- Read the house’s sitting direction — which quarter the building’s back rests against, which decides the house’s group.
- Match first — same group, the pairing is in step and the fine work is placement; different group, do not treat the house as failed — put the big three (the door, the bed, the stove) on your own favorable directions instead of moving.
- Rank the favorable four — Sheng Qi first (the door’s direction most of all), then Tian Yi for the bed (the star of health), Yan Nian next, Fu Wei last.
- Fence off the worst two — the bed head and the desk stay off Jue Ming and Wu Gui; Huo Hai and Liu Sha are the milder pair, and where the plan of the house forces a compromise, the compromise is spent there.
The bed’s placement rules are the bedroom page’s subject and hold independently of your number; the stove’s seat is the kitchen page’s; the desk’s facing question has its own home office page, with the same order this page ends on — placement first, direction second. What the ming gua adds to each is the second half of the question: not only where the bed or the desk should sit, but which way it should point, for you, born the year you were born. For renters the house is not on the table at all — but the bed’s pointing, the desk’s facing and the stove’s use are, and that is most of what the method can be asked to say.
Eight mansions and the bagua map#
The bagua map laid out on this site is the universal layer: one chart, every reader, north meaning what north means, southeast what southeast means. Eight mansions is the personal layer that fastens on top of it — the same eight directions, re-read from one person’s birth year. The two layers do not compete: the universal map gives a direction its standing, the personal grid says whether that standing runs with you or against you, and the order to take them in is the order the room pages already teach — universal first, personal second, placement before either.
This is the page the room pages were pointing to. The bedroom page parks the headboard’s pointing question at the fate trigram; the home office page parks the desk-facing question there; the front door page parks the door’s favorable sector at the kua number; the living room page’s seating line runs on the same machinery. Each of them says, in its own words: fix placement first, take up the direction layer second — and this page is the direction layer, the bagua map under it and your own number on top.
A reader’s comparison: Vastu Shastra#
Readers who know India’s building tradition will recognize the shape. Vastu Shastra also runs a layer of direction readings — quarters, entrances, kitchens — and it also carries a personal layer: the favorable quarters of a given occupant are read against the birth chart, so that two people in one house may be advised differently. The shared intuition is the one this whole page has been machinery for — that a dwelling’s directions and a person’s birth may stand in some correspondence. The difference is where the personal part comes from: Vastu’s runs to the planets and houses of a natal chart, while eight mansions compresses the whole person into one trigram computed from a single stem-branch year. An astrology’s sky against one year number — different inputs, same instinct, and both are traditional readings, held here as readings.
A five-minute check#
- Is your ming gua computed — the number, the trigram, the group?
- Is the house’s sitting direction read — east house or west?
- If the pairing is out of step, do the big three (door, bed, stove) sit on your four favorable directions rather than on the worst two?
- Does the bed head point to Sheng Qi, Tian Yi, Yan Nian or Fu Wei — and the desk likewise?
- Are the bed head and the desk off Jue Ming and Wu Gui, with any forced compromise spent on Huo Hai or Liu Sha instead?
One number, one sitting direction, and the personal layer of the house’s chart is drawn. For renters the list is shorter still — the bed’s pointing and the desk’s facing are the two things in the house you own outright.
Related: What Is Feng Shui · Feng Shui Bagua Map Explained · Front Door Feng Shui · back to Physiognomy & Feng Shui · Foundations