The Eight Du Nien: How Sinh Khí, Thien Y, Diên Niên, Phục Vị, Họa Hại, Lục Sát, Ngũ Quỷ, and Tuyệt Mệnh Are Calculated and How to Place the Door, Master Room, and Kitchen According to Dương Trạch Tam Yếu

What are the eight du niên and why are they called du niên?

Du niên is the collective name for the eight states used in the Bát Trạch school of dương trạch (yang dwelling) feng shui. Those eight states are Sinh Khí, Thiên Y, Diên Niên, Phục Vị, Họa Hại, Lục Sát, Ngũ Quỷ, Tuyệt Mệnh. The word du niên here carries the meaning of moving, cycling: each time the direction being examined changes, the relationship between the base trigram and that direction shifts to another state.

Four du niên are considered auspicious: Sinh Khí, Thiên Y, Diên Niên, Phục Vị. Four du niên are considered inauspicious: Họa Hại, Lục Sát, Ngũ Quỷ, Tuyệt Mệnh. This is the classification used by the Bát Trạch school, not a statistical result.

How do the life trigram and the direction trigram differ?

The life trigram is tied to the birth year and gender of the person living in the house, while the direction trigram is tied to the orientation of the house or the orientation of the main door. Bát Trạch Minh Kính, attributed to Nhược Quán đạo nhân of the Qing dynasty, takes the person's cung phi (life palace) as the base and compares it with the eight directions. Dương Trạch Tam Yếu by Triệu Đình Đống, courtesy name Cửu Phong, of the Qing dynasty, takes the main door as the base and derives the remaining palaces from it, while emphasising three factors: the door, the master (master room) and the kitchen.

The two methods produce two different tables, and this is why the same house can be read by two masters with two different results.

Where do the cung phi 5 of men and women go?

This is where the books do not agree. When calculating the cung phi and the number 5 comes up, no trigram corresponds to the number 5 in the Bát Quái, so it must be sent to another palace. Some books send the cung phi 5 of men to Khôn and of women to Cấn, some books do the opposite, and some books send both men and women to the same palace. The Nhật Nguyệt utility sends men to Khôn and women to Cấn; if you look up a table and find it off by one palace compared with someone else's result, check which convention each side is following before concluding who is right and who is wrong.

How does the line-changing method from the base trigram to the other trigrams work?

The line-changing method is a way of calculating the eight du niên by flipping the yin-yang sign of each line in the trigram. Each Bát Quái trigram has three lines, each line either yin or yang. We flip in turn the top line, the middle line, the bottom line, then repeat the middle line, the top line, the middle line, the bottom line, the middle line. Eight flips produce eight trigrams, corresponding in turn to Sinh Khí, Ngũ Quỷ, Diên Niên, Lục Sát, Họa Hại, Thiên Y, Tuyệt Mệnh, Phục Vị. The eighth flip returns to the base trigram, which is Phục Vị.

For example, with the Khảm trigram: the first flip gives Tốn, corresponding to Sinh Khí; the second gives Cấn, corresponding to Ngũ Quỷ; the third gives Ly, corresponding to Diên Niên; and so on until it returns to Khảm. Chấn is the Thiên Y of Khảm, not the result of the second flip. For a quick lookup, see the table at the end of the article.

How are the meanings of the eight du niên understood?

The popular interpretation holds that Sinh Khí is the best star, governing wealth luck and health; Diên Niên, also called Phúc Đức, governs fortune, longevity and harmony; Thiên Y helps reduce illness and increase longevity; Phục Vị is moderate, governing stability. In the inauspicious group, Tuyệt Mệnh is usually considered the worst, governing disaster, illness, separation and loss; Ngũ Quỷ causes sudden misfortune, disputes and lawsuits; Lục Sát leads to discord, conflict and loss; Họa Hại causes gossip and affects health.

Assigning the five elements to each du niên, for example Sinh Khí belonging to Mộc, Diên Niên to Kim, Phục Vị to Thủy, is a convention of modern feng shui books and may be recorded differently from book to book. Concepts such as vượng trạch cách, sanh trạch cách, or the relationship that Đông tứ trạch belongs to Mộc and Tây tứ trạch belongs to Kim are likewise conventions, not a conclusion shared by all schools. The degree of good or bad also depends on the interaction between the star and the palace position, so one should not assert absolute auspiciousness or inauspiciousness.

How do auspicious stars in đăng diện, đắc vị and thất vị differ?

According to the reasoning of the Bát Trạch school, when an auspicious star shines into a palace whose element is in harmony with it, this is called đăng diện and is considered the best; shining into a palace that generates it is called đắc vị, second best; shining into a palace that it clashes with or that clashes with it is called thất vị, and its effect is diminished. For example, Thiên Y belongs to Thổ, meeting Cấn and Khôn, which also belong to Thổ, is đăng diện; meeting Ly, which belongs to Hỏa, and Đoài and Càn, which belong to Kim, is đắc vị; meeting Chấn and Tốn, which belong to Mộc, and Khảm, which belongs to Thủy, is thất vị.

This three-level classification is a metaphysical interpretation at a reference level, explaining why two houses both place the kitchen in the Thiên Y direction yet one is praised as prosperous and the other is only considered acceptable. It should not be treated as a binding rule for every case.

How does Dương trạch tam yếu take the door as the base?

According to Dương Trạch Tam Yếu by Triệu Đình Đống, courtesy name Cửu Phong, of the Qing dynasty, three factors are emphasised: the main door, the sơn chủ or master room, and the position of the kitchen. The book takes the main door as the base to derive the remaining palaces, and from there reasons about the position of the master room and the kitchen. In other words, Bát Trạch Minh Kính asks which direction suits this person, while Dương Trạch Tam Yếu asks, once this door opens, what the palaces in the house become.

Mechanically applying one theory while ignoring the other is something to avoid. Each method has its own frame of reference, and the results can differ for the same house.

Which stars should doors, master rooms and kitchens be arranged by?

According to the reasoning of the Bát Trạch school, for a house to prosper, the placement of the master room and the kitchen should fall into auspicious du niên palaces at the đăng diện or đắc vị level; in the weakest case they should only be placed in an auspicious du niên palace at the thất vị level. The table below summarises the placement guidance by star, at a reference level.

Why must the kitchen sit on the inauspicious and face the auspicious?

The principle of sitting on the inauspicious and facing the auspicious means the back of the kitchen rests on an inauspicious direction, while the front of the kitchen looks toward a good direction. The common explanation is that the kitchen belongs to Hỏa, so its back is placed toward an inauspicious direction to suppress bad energy, while its front faces a good direction to receive good energy. This is a principle of the Bát Trạch school, at the level of reference metaphysical interpretation.

There are two opposing theories about the stove position: one theory holds that the kitchen should be placed in an auspicious direction, the other holds that the kitchen must be on the same side as the house, so a Tây trạch house has its kitchen on the west side and an Đông trạch house has its kitchen on the east side, in order to regulate and create balance among the three factors of door, master and kitchen. Users should know both in order to avoid mechanically applying one theory.

What is the connection with Đông tứ trạch and Tây tứ trạch?

The Đông tứ trạch palaces are Khảm, Ly, Chấn, Tốn, while Tây tứ trạch consists of Càn, Khôn, Cấn, Đoài. When palaces within the same group combine with one another, they usually produce auspicious du niên, while when the two groups intersect, they tend to produce inauspicious du niên. This is the grouping convention of the Bát Trạch school, not a statistical result.

This grouping explains why people often say that a person of Đông tứ mệnh suits an Đông tứ trạch house. But it should be noted that this is the convention of one school, not an absolute truth for every specific case.

Points to keep in mind when looking up tables yourself

First, you must clearly determine whether you are following Bát Trạch Minh Kính, which takes the person's cung phi as the base, or Dương Trạch Tam Yếu, which takes the door as the base, because the two methods give different tables. Second, you must handle the cung phi 5 according to the convention of the book you are using, and state that convention clearly when presenting results. Third, you must distinguish đăng diện, đắc vị and thất vị when judging the degree of good or bad, rather than stopping at the name of the star.

Fourth, some reasoning notes that Dương Trạch Tam Yếu does not exist independently. A house with a good layout according to the three essentials but located near a cemetery, a hospital or a place with much yin energy will have reduced effect. Conversely, a house with an imperfect layout but in a favourable location or meeting good timing can still bring good fortune. The du niên stars are only one layer of information; the same direction can be good for one person and bad for another, depending on the life trigram. Therefore one should not assert absolute auspiciousness or inauspiciousness for any position without considering the remaining layers.

How do you look up the du niên of a direction by cung phi?

Find the row of the cung phi, then read the cell in the column of the direction you want to examine. The table is built from the Nhật Nguyệt calculation core, using the same data as the house direction utility; cung phi 5 follows the utility's convention: men use the Khôn row, women use the Cấn row.