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House-building year check
The three taboos Kim Lâu, Hoang Ốc and Tam Tai all count lunar age rather than solar age, and most people fall under only one of the three. Lunar age here follows the solar year without adjusting at Tết, because every table in circulation does the same. The useful answer is therefore not that an age is bad, but which of the next ten years is clear.
Check the three Vietnamese folk taboos for building a house (Kim Lâu, Hoang Ốc, Tam Tai) by lunar age, with the arithmetic shown, a ten-year scan for a clear year, and how age-borrowing works. Birth year only.
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How are Kim Lâu, Hoang Ốc and Tam Tai calculated?
Before breaking ground, Vietnamese custom checks three taboos against the person who will own the house: Kim Lâu, Hoang Ốc and Tam Tai. All three are read from LUNAR age, the build year minus the birth year, plus one, not the Gregorian age. So one person's reading changes once a year, and everyone born in the same year gets an identical result.
Kim Lâu divides lunar age by 9: remainders of 1, 3, 6 or 8 count as affected; other remainders do not. Each of the four has a name for whoever folk belief holds is affected, 1 the owner, 3 the wife, 6 the children, 8 the livestock.
Hoang Ốc counts through six positions in the order Nhất Cát, Nhì Nghi, Tam Địa Sát, Tứ Tấn Tài, Ngũ Thọ Tử, Lục Hoang Ốc. The traditional count moves through the tens first, age 10 starts at Nhất Cát, 20 at Nhì Nghi, 30 at Tam Địa Sát, then counts on by the units digit. Three positions are favourable and three are not. A shortcut taught in some texts, summing the two digits and dividing by six, gives the same answer for every two-digit age, because that sum is exactly tens plus units.
Tam Tai runs by the Tam Hợp trine of your birth branch, each group meeting three consecutive years: Monkey/Rat/Dragon in Tiger, Rabbit and Dragon years; Tiger/Horse/Dog in Monkey, Rooster and Dog years; Snake/Rooster/Ox in Pig, Rat and Ox years; Pig/Rabbit/Goat in Snake, Horse and Goat years. The cycle is fixed, so anyone can see their Tam Tai years well in advance.
To be plain about it: these are folk beliefs with no scientific basis, and the schools do not agree among themselves, some read only Kim Lâu, others all three. Kim Lâu and Hoang Ốc are arithmetic on a single age number; they use no stems, no five-element analysis and no birth chart, so they are not a personalised astrological reading. This page publishes the exact method it uses so you can cross-check it against other tables.
Finding a year clear of all three is hard, especially during your three Tam Tai years. In practice people commonly proceed when only one applies, and the usual workaround is to borrow an age: asking someone unaffected that year to perform the groundbreaking and roof-raising rituals on their behalf. The symbolic sale document in that custom is ritual only. It has NO legal force and must never be replaced with a real transfer of title.
| Taboo | Method | Applies when |
|---|---|---|
| Kim Lâu | Lunar age divided by 9, take the remainder | Remainder 1, 3, 6 or 8 |
| Hoang Ốc | Count 6 positions by tens then units | Lands on Tam Địa Sát, Ngũ Thọ Tử or Lục Hoang Ốc |
| Tam Tai | By the Tam Hợp trine of the birth branch | The year falls in the group's three Tam Tai branches |
Frequently asked questions
Do I need my birth date and hour to check a house-building year?
No. All three taboos use only the birth year: Kim Lâu divides lunar age by 9, Hoang Ốc counts positions by age, Tam Tai reads the birth branch. None of the arithmetic touches the day, month or hour. A site that asks for all of them to read these three taboos is collecting data it does not use, and your result will still match everyone born in the same year.
What is lunar age and how is it counted?
Lunar age is the build year minus the birth year, plus one. Someone born in 1990 is lunar age 37 in 2026, even before their Gregorian birthday. All three taboos read this number, not the Gregorian age.
Can I still build if one of the taboos applies?
These are folk beliefs, not prohibitions. In practice most people proceed when only one applies, often borrowing an age for the rituals. A year clear of all three is genuinely hard to find, especially during your own three Tam Tai years.
What is age-borrowing, and does it carry legal risk?
You ask someone unaffected that year to perform the groundbreaking and roof-raising on your behalf, with a symbolic sale document, then buy the house back when it is done. That document is ritual only and has NO legal force. Never carry out a real transfer of title to perform this custom, the ritual is symbolic, but a registered transfer is real and very hard to undo.
Is Kim Lâu different for women?
Some texts hold that Kim Lâu is read differently for women, but the lookup tables in circulation for house-building do not split by gender, they read the age of whoever will own the house. This page follows the common tables so you can cross-check, and uses gender only for the Eight Mansions orientation section, where the calculation genuinely does differ.
Do these three taboos have any scientific basis?
No. Kim Lâu and Hoang Ốc are arithmetic on a single age number, using no stems, five-element analysis or birth chart; Tam Tai is a fixed three-year cycle by trine. This is folk knowledge worth recording as culture, and worth reading as culture, not as a forecast.
Once I have a year, what else is there to choose?
The three taboos judge the YEAR only. The month, the groundbreaking date and hour, and the house orientation all remain. Dwelling feng shui also weighs terrain, surroundings and interior layout, things only an on-site survey can judge, not something derivable from a birth year.
Why does this page show the arithmetic?
Because you should be able to check it. Most pages in this space return a bare "applies" or "does not apply" and ask you to trust it. Here each taboo prints its division and remainder, so you can redo it on paper and compare against any other table.