You'll be able to read up on many of the various house systems... such as Placidus (rumored to be as old as 13th Century but first confirmation in 17th Century), Equal, Porphyry (2nd or 3rd Century), Campanus (13th Century), Koch (1971), Regiomontanus (15th Century), and Alcabitius (1st Century) (and more)... and their various theoretical rationales. (Most of them will be relatively accurate as to details.)

Recommended link to Astro Communication Services pdf file on house systems.

Confessions of a Wooly Minded Archetypal Astrologer
Due to my having previously moderated a fairly active astrology forum for 7 years, I realize what a burning question this is for folks relatively new to the study of serious astrology, as well as, an often highly heated (ie sometimes downright nasty and rancorous) topic for those folks who have been around for a while.

Some folks new to astrology have even used the "house system issue" as a rationale for not furthering their studies of astrology... whatever... I suppose it can be frustrating being told that there's no one definitive answer to the question of which house system one should use. If I'm honest... I can still remember when it used to frustrate me.

On With The Confession
As much as I hate to admit it... a good part of why I use Koch (as opposed to Placidus) is probably because Koch is the first house system I was introduced to.

The very first paid birth chart reading I received utilized the Koch House System.

Curiously, in hindsight, I have to wonder if my introduction to Koch was nothing more than a "fortunate mistake" due to my astrologer having not yet fully mastered her ancient DOS astrology software (or her knowledge of astrology), as I distinctly remember her telling me that she utilized the Equal House System. Take my word for it... it's a wee bit hard to confuse the Koch House System with the Equal House System.

Also, at the time I started to further my astrological studies, the Koch House System (although Placidus was then and now clearly the most popular) appeared to be gaining a wide popularity amongst my peers. My own personal favorite astrological writer (Stephen Arroyo) at the time, appeared to primarily be using Koch. It later appeared that Rob Hand was (at that time) primarily using the Koch House System.

Skuttlebutt at the time was that Koch tended to work better on an "external" level and (among other things) was generally better for predictive purposes, while Placidus was primarily "internal" and "psychological" in nature. I find it more than a little amusing that nowadays some of the more prominent users of Koch feel that Koch is more "psychological" in nature and Placidus is more "external."

At the time, while sticking with Koch, I nevertheless experimented with (primarily) Placidus, Equal, and Porphyry. I finally came to the decison that I did my best work using Koch. (FYI - although you'll likely only hear it here, Koch is very similiar to the much older Alcabitius.)

Why Is Placidus King?
Placidus is king primarily because during the 19th Century and much of the 20 Century, it was the only house system easily available to rank and file astrologers via Raphael's Ephemeris.

Whether or not they can bring themselves to admit it... most astrologers, like me, tend to go with what they were first introduced to. Most folks (even today) are first introduced to Placidus.

Bottom Line
My best advice is don't get too worked up about the whole thing... and try to treat the 8 non-angular house cusps as nothing more than (imprecise) rule of thumb guideposts. It's the 4 angles of the chart (Ascendant, IC, Descendant, and Midheaven) serving as the cusps of the 1st, 4th, 7th and 10th houses that you can count on and should probably be focusing the most on.

Home > Basics > Choosing a House System

If all of this is way beyond you, go here for Dr Z's take on what the 12 houses of the birth chart represent.