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what are house systems in astrology? 
there are 12 houses in astrology, each with their own meaning and role in a chart. there are a lot of different interpretations of the houses, but that itself isn't a house system. a house system is a method of dividing a chart into the 12 houses.
every chart has 12 houses. this is a fundamental part of astrology, and it doesn't change no matter which system you use. some places show you a table that makes it look like you don't have all 12. this is wrong, and I highly recommend learning how to read a circle chart instead
There are a few house systems that are widely used, and I'll go into each one and its pros and cons separately.
-placidus
-equal
-whole sign
there are a lot of other systems too, but they're used less commonly and the differences are a lot less notable.
-placidus
-equal
-whole sign
there are a lot of other systems too, but they're used less commonly and the differences are a lot less notable.
Other house systems include:
-koch
-porphyry
-meridian
-campanus
-regiomontanus
Note: if you are a beginner or novice, I don't suggest using these systems.
-koch
-porphyry
-meridian
-campanus
-regiomontanus
Note: if you are a beginner or novice, I don't suggest using these systems.
PLACIDUS HOUSES
Placidus is the most commonly used house system. It's the default on most websites and apps and chances are you know your placidus house placements.
In placidus, the ascendant degree is always the beginning of the 1st house and the midheaven degree is the beginning of the 10th house
The rest of the houses are defined by taking the time it takes for the AC to become the MC and dividing it by thirds. This creates the 11H & 12H
The rest of the houses are defined by taking the time it takes for the AC to become the MC and dividing it by thirds. This creates the 11H & 12H
This is also done with the IC to the ascendant to draw the 2H and 3H. Because placidus is symmetrical across the ascendant axis, this also creates the rest of the houses by default.
It should be noted that I'm simplifying this math a lot for the sake of convenience.
It should be noted that I'm simplifying this math a lot for the sake of convenience.
Placidus charts are good for a lot of techniques like horary and electional astrology because of the emphasis it puts on house sizes. However, this can also cause confusion, especially for beginners.
Placidus (and other time based systems) can create interceptions, which can appear in a table chart as missing houses. this is because in placidus it's common for a house to engulf an entire sign, meaning that sign doesn't have a house of it's own, like this:
In this chart, pisces and virgo don't have their own houses, while sagittarius and gemini both have two. This can be confusing, especially if you have placements in those intercepted signs, like Ariana Grande does. Her virgo mars is in the 8th house, but her 8th house is leo.
If you just looked at the table chart, you might not even know that she has virgo or pisces at all (this is why you shouldn't use table charts btw!!)
Also, placidus doesn't work if you were born near the poles. The houses get skewed and end up looking like this mess:
Also, placidus doesn't work if you were born near the poles. The houses get skewed and end up looking like this mess:
Placidus summary:
☆ PROS: house division is unique to your chart and cusps can be used as points of emphasis/interpretation
☆ CONS: interceptions can be confusing or misleading and this system doesn't work if you were born very far north or south
☆ PROS: house division is unique to your chart and cusps can be used as points of emphasis/interpretation
☆ CONS: interceptions can be confusing or misleading and this system doesn't work if you were born very far north or south
WHOLE SIGN HOUSES
The name says it all for whole sign houses. Each sign gets its own house, and each house is divided into an equal 30°.
The ascendant is a point in the 1st house, rather than the start of the 1st. The MC can be in the 8H, 9H, 10H, or 11H and rarely even in the 7H or 12H.
The ascendant is a point in the 1st house, rather than the start of the 1st. The MC can be in the 8H, 9H, 10H, or 11H and rarely even in the 7H or 12H.
Examples of the midheaven in different houses using whole signs:
Some people don't like this, because they believe that the AC/MC/DC/IC are more important than just being points inside a house and their axis should be clearly visible in the chart.
In my opinion, whole signs are the best option. They're much simpler for beginners as there's fewer things like interceptions to deal with. They also make tracking transits way easier because you don't have to know the specific degree of the planet to know what house it's in.
WSH also is the best system for methods like zodiacal releasing and synastry.
Whole Signs summary:
☆ PROS: much easier to read, ideal for beginners, more practical for transits, synastry, and zodiacal releasing
☆ CONS: houses are not specific to you, AC/MC are points in the houses rather than defining the beginning of their house
☆ PROS: much easier to read, ideal for beginners, more practical for transits, synastry, and zodiacal releasing
☆ CONS: houses are not specific to you, AC/MC are points in the houses rather than defining the beginning of their house
EQUAL SIGN HOUSES
Equal sign houses are the happy medium between placidus and WSH.
Each house is still divided into equal 30° sections with one sign per house, but rather than starting at 0° of each sign, the 1st house starts at the degree of the ascendant and the rest of the houses follow suit
Each house is still divided into equal 30° sections with one sign per house, but rather than starting at 0° of each sign, the 1st house starts at the degree of the ascendant and the rest of the houses follow suit
This is the system to use if you want to have more personalized house cusps with slightly easier tracking of transits. It's the libra of house systems.
Examples of equal houses:
Examples of equal houses:
Equal Houses summary:
☆ PROS: more individual cusps but still regularly sized houses, ascendant is the most important degree in the chart
☆ CONS: mc/ic still don't begin their own house, have to pay slightly more attention to the degrees of transits
☆ PROS: more individual cusps but still regularly sized houses, ascendant is the most important degree in the chart
☆ CONS: mc/ic still don't begin their own house, have to pay slightly more attention to the degrees of transits
Now onto the less common house systems!
KOCH:Like Placidus, Koch is a time based system. It's called the "house system of the birth place" and is calculated from the midheaven and the horizon lines at different times of day using a similar method to placidus.
In the Koch system, the midheaven is the defining degree of the chart instead of the ascendant. This puts more emphasis on the MC/IC axis.
Here's a comparison of the same chart in Koch, Placidus, and WSH
Here's a comparison of the same chart in Koch, Placidus, and WSH
It should be said that like placidus, Koch starts to break if you were born far north or south.
☆ PROS: emphasis on midheaven, similar to placidus
☆ CONS: ascendant is no longer most important degree, stops working near the poles
☆ PROS: emphasis on midheaven, similar to placidus
☆ CONS: ascendant is no longer most important degree, stops working near the poles
PORPHYRYThis system is very simple. It starts with the 4 quadrants (the spaces between the axis) and divides them into equal sections to get the rest of the houses.
This keeps the emphasis on the important angles of the chart while also having more equally sized houses.
This doesn't mean all the houses will be the same size though.
Example (compared to WSH):
Example (compared to WSH):
☆ PROS: emphasis on the angles, slightly more regular house sizes
☆ CONS: can still create interceptions
☆ CONS: can still create interceptions
MERIDIAN Unlike placidus and other time based systems, the meridian house system is oriented by both time AND space.
This system also puts emphasis on the midheaven. The MC defines the 10th house cusp, but the Ascendant is not the cusp of the 1st house.
In meridian, houses are very close to equal in size. The only reason they are not exactly the same is because each house is exactly 2 hours of sidereal time. The variations in house sizes are within just a few degrees.
Example of a Meridian vs Equal houses (midheaven) chart:
Example of a Meridian vs Equal houses (midheaven) chart:
☆ PROS: midheaven is a defining angle, houses are fairly equal, uses both time and space to calculate chart
☆ CONS: ascendant is not a defining angle, houses are not exactly equal so you have to remember more degree points.
☆ CONS: ascendant is not a defining angle, houses are not exactly equal so you have to remember more degree points.
CAMPANUS Like Meridian, Campanus is a space-oriented system. However, it is not time-oriented.
Campanus divides the chart into 12 equal houses from what's called the prime vertical (this method is very astronomy-heavy)
This gets more into astronomical math that I'm not qualified to discuss, but Campanus is technically considered an equal house system because the houses are defined by "the points where the twelve circles cross the ecliptic"
Examples of Campanus vs Equal sign houses:
Examples of Campanus vs Equal sign houses:
☆ PROS: space-based, astronomically accurate
☆ CONS: requires mathematic and astronomical knowledge beyond what most of us have to really understand
☆ CONS: requires mathematic and astronomical knowledge beyond what most of us have to really understand
REGIOMONTANUSThis system is very similar to Campanus in its method of calculation and in that it's a space-oriented method, but the houses are not all equally sized in space.
House cusps are defined by where lines drawn from the "great circles" cross the ecliptic
Again, this system is very math-based and astronomy-heavy.
Here's an example of a chart in Regiomontanus, Campanus, and Equal Sign houses:
Here's an example of a chart in Regiomontanus, Campanus, and Equal Sign houses:
☆ PROS: space-based, similar to campanus
☆ CONS: math :(
☆ CONS: math :(
There are dozens of house systems to explore and chose from, each with their own benefits and drawbacks. Each has it's own system of calculation and methods for which it's best to use.
Exploring these differences can be a great way to learn about your chart!
Exploring these differences can be a great way to learn about your chart!
