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Astrological House Systems

Astrological House Systems, Earth's Ecliptic

Updated September 16, 2019
By Corinne Lane     6 Comments

Most astrology charts are made of a map of the heavens overlayed upon a circle of 12 houses (see explanation of a Chart Layout). Several methods exist for calculating the line divisions between the houses (house cusps), and not all astrologers use the same method.

It is believed that we exist in time and space. The purpose of the astrological houses is to divide our reality into sections. One method is to divide a day’s time (24 hours and 1 complete revolution of Earth about its axis) into 12 divisions. House systems that focus on this method are called “time-based” systems. Another method is to divide the space inside the Earth’s atmosphere into 12 sections, like sections of an orange.

Over the years, people have proposed many different formulas for calculating the divisions with both of these methods. That is why we have so many different house systems in astrology.

You can find many summaries of the house systems on the web, so I will only list the most popular and add a few notes below.

List of House Systems

The Placidus house system is probably the most widely-used in the United States and Europe. However, here at Astrology Library, we consider the Placidus house system our second favorite, not our first choice.
The Koch house system is probably the second most popular in the United States. It’s a relatively new system, from the 1970’s. It doesn’t work at all near the poles of Earth, but it’s still very popular.
The Campanus house system is our favorite at Astrology Library. We find that it works best for psychological readings, as opposed to mundande or electional. We are not alone in our support of the Campanus house system: Dane Rudyhar also preferred it.
Equal Houses
The Equal House system was the earliest system used. The ascendant makes the 1st house cusp, then each successive house cusp is exactly 30 degrees after the previous one. The advantage of this house system is that it works well from any point on Earth since the houses are always 30 degrees. The houses do not grow or shrink in size near the poles, as in other house systems. A most annoying issue with this house system is that the M.C. is not the same as the 10th house cusp.
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  1. Kate Giuchici on said:

    I have used both the Placidus and Equal house systems for years now. Experimenting with astrology software and applications — trying to find the best within my tight budget —
    Some don’t even have Placidus as an option. For instance, Janus 4 doesn’t use Placidus (unless it’s named something else that I haven’t heard of…). Janus4 happens to be in my top 3 astrology programs. The others being a)astrowin and b)astro123, both of which are free, but only compatible with a PC.
    The fact that you referenced Dane Rudhyar, was the last tidbit I needed to convince me. He is by far the best that I’ve read, and in my opinion. Don’t get me wrong, many are just as respectable for their knowledge and experience. …Rudhyar has had the biggest influence on my journey with astrology. and I suppose, by default, Michael Meyer with his “translation” of Rudhyar’s person-centered, humanistic approach to the craft. (Michael Meyer ‘Handbook for the Humanistic Astrologer’.

    Basically, the name-dropping worked on me. ;)
    p.s. unintentionally loooooonng-winded.

    thank you for the post.

  2. Walter Pullen on said:

    Cool, another supporter of the Campanus house system! :) Campanus is the simplest and most direct space-based house system. As we know, the 12 signs of the zodiac form 12 equally sized “orange wedges” aligned with the ecliptic. The simplest and best way to visualize houses is also as 12 equally sized “orange wedges”, however aligned instead with the local horizon. Where the ecliptic intersects the 12 house wedges defines Campanus house cusps.

    Note it’s possible to go a step further, and truly use the 3D Campanus model of 12 house “orange wedges” to place planets within houses. In other words, take planetary latitude into account, resulting in a true “3D houses” model:

    • PersisRose on said:

      whoa! This is absolutely amazing! Wow! I wish I could interpret this as u would a 2D chart! Thank you! Truly beautiful!

  3. Joyce Wehrman, said suggested to use the Koch H system,. especially good for timing of planetary transit cusps.. and her ‘Winning Transits’ program. I was also taught to use Campanus for proceeded Solar Returns. See: Interpreting Solar Returns by James A Eshelman. thanks!

    • Exhaustive research on the systems with many clients over years, experimenting with various models from equal to sunshine houses and being the lucky holder of a chart that has several planets that are close to cusps so move from one house to another depending on the system has led me to conclude Koch is the most accurate system. There is a reason it grew in popularity so quickly despite so many others to choose from. And is used by research astrologers. To Walter Pullen’s point, the 12 equal divisions work as constructs for the Zodiac up there. Down here, it makes deep sense that the houses are not 12 neat divisions of the sky. Earth based realities are not linear. The earth is tilted on an axis, its not perfectly round, has variations of night and day time length depending on hemisphere and season. There is variabilty. This is well reflected in our lives and individual stories by house systems which have unequal houses, interceptions, slanted axes, etc. To use a 12 equal division model as a starting point is a wistful notion. What is elegant theoretically is too often untrue in reality. In practice, looking as empirically as possible, Koch won out handily.

  4. What about whole signs?

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