ASTROLOGY HOUSE SYSTEMS — PLACIDUS, WHOLE SIGNS, KOCH & MORE: HOW THEY WORK AND WHEN TO USE EACH

One of the first things you notice when you go deeper into astrology is that charts can look very different depending on the house system you use. Planets move houses, interceptions appear or disappear, angles shift, and suddenly interpretations change. This doesn’t mean astrology is broken — it means house systems are different ways of mapping lived experience.

House systems don’t change the planets or signs. They change how life areas are divided. Each system highlights a slightly different layer of reality.

PLACIDUS — THE LIVED, PSYCHOLOGICAL CHART

Placidus is probably the most widely used modern house system, especially in psychological and counseling astrology. It divides houses based on time — how long it takes planets to rise and set at a specific latitude.

Because of that, Placidus tends to reflect subjective experience very well. It shows where life feels stretched, compressed, delayed, or emphasized. This is also why interceptions appear in Placidus: some themes take longer to develop, or feel harder to access early in life.

Placidus works especially well when you’re interested in:

daily life patterns psychological development family dynamics inner experience health and routine transits and progressions

It’s also very sensitive to latitude, which makes it excellent for people born far from the equator, but less stable near the poles.

If someone says, “This chart feels exactly like my life,” it’s often Placidus.

Example: Someone might have a very large 6th house and a tiny 7th house. In real life, they may spend years focused on work, health, routine, or survival mode, while relationships feel secondary or come later. Intercepted signs often describe themes that are present but harder to access early on, sometimes unlocking with age or experience.

WHOLE SIGN HOUSES — THE STRUCTURAL, SYMBOLIC MAP

Whole Sign houses are one of the oldest systems. Each sign equals one house, starting from the rising sign. The degree of the Ascendant still matters, but it doesn’t divide the houses themselves.

Whole Sign charts tend to feel clean, logical, and archetypal. They describe what topics belong to which areas of life in a very clear way. Because there are no interceptions, everything has a place — nothing is hidden structurally.

This system works beautifully when you’re looking at:

life themes and topics career direction timing through annual profections traditional techniques fate-based or event astrology

Whole Sign houses are especially strong for prediction, long-term life themes, and traditional methods. Many people find that Whole Sign charts describe what happens, while Placidus describes how it feels.

Example: If someone has Capricorn rising, their entire 10th house is Libra, regardless of degree. Venus rules career matters, even if the Midheaven is somewhere else. In real life, this often shows up as a career shaped by Venusian themes: art, aesthetics, diplomacy, social roles, or working with people.

KOCH — THE DEVELOPMENTAL SYSTEM

Koch houses are also time-based, but they emphasize personal development and the unfolding of life stages. This system can feel very precise when birth time is accurate.

Koch often highlights when someone steps into certain roles or life areas, especially around identity, career, and self-direction. Some astrologers find it extremely accurate for personal growth work, while others find it too sensitive.

Koch tends to work best when:

birth time is very exact you’re analyzing life transitions you’re focused on self-actualization you want a strong connection between inner growth and outer events

It can become unstable at extreme latitudes, similar to Placidus.

Example: Someone may have planets clustered near the 10th house cusp in Koch, even if they fall solidly in the 9th in Placidus. In real life, this person might grow into their public role later, with career becoming central only after a certain age or internal shift.

EQUAL HOUSE — THE SIMPLIFIED, TECHNICAL SYSTEM

Equal House systems divide the chart into equal 30° houses starting from the Ascendant degree. This creates a very consistent structure and keeps houses clean and balanced.

Equal House charts are often used when:

birth time is uncertain you want clarity without distortion you’re focusing on technical interpretation you prefer simplicity over nuance

They can feel less psychologically detailed than Placidus, but very reliable structurally.

Example: Someone with an Ascendant at 12° Virgo will have their 2nd house start at 12° Libra, their 3rd at 12° Scorpio, and so on. This can be very helpful when birth time is uncertain, because the structure stays stable.

CAMPANUS & REGIOMONTANUS — SPATIAL SYSTEMS

These systems divide the chart based on space rather than time. They’re less commonly used today, but still important, especially in horary and medieval astrology.

They tend to work well for:

horary questions event-focused charts location-based interpretation

They can feel less intuitive for personality analysis, but very sharp for specific outcomes.

Example: In a horary chart asking about a lost object, Regiomontanus often places the significators in very specific spatial relationships that make answering the question clearer. These charts tend to be less about personality and more about outcomes.

SO… WHICH HOUSE SYSTEM IS “RIGHT”?

This is where experience matters more than ideology.

Different systems describe different layers of reality:

Whole Sign often shows what happens

Placidus shows how it’s experienced

Koch shows how it unfolds over time

Equal House shows clean structure

Many astrologers quietly use more than one system, even if they don’t always say it. A chart can be read through multiple lenses, each adding something different.

If someone’s chart suddenly “makes sense” when switching systems, that doesn’t mean the first system was wrong — it means a different layer of the chart needed attention.

A PRACTICAL WAY TO WORK WITH HOUSE SYSTEMS

If you’re learning or practicing astrology, try this: Look at your chart in Placidus and Whole Sign side by side. Notice which one describes your lived experience better, and which one explains your life events more clearly.

For psychological work and self-understanding, Placidus often feels very accurate.

For timing, career themes, and traditional techniques, Whole Sign often shines.

You don’t have to choose one forever. Astrology isn’t about loyalty to a system — it’s about understanding reality more clearly.

FINAL THOUGHT

House systems aren’t competing truths. They’re different maps of the same terrain. Some show emotional contours, some show structural boundaries, some show timing.

If astrology teaches anything, it’s that reality has layers — and sometimes you need to change the map to see what was already there.

✨AstroHolic✨

Art Deco Russian Aquamarine and Diamond Kokoshnik Tiara by Koch, Circa 1914

Ah yes, ye age olde debate... which house system to use?

When first getting into astrology, the majority will use the placidus house system whether or not they know it. Placidus is the default for modern/ pop astrology; every chart generation website automatically uses it. Nowadays, the most common runner up house system to placidus is Whole Signs (often used by traditional/hellenistic astrologers). Yet, there are many house systems...:

➔Whole signs ➔Placidus ➔Koch ➔Equal/ Equal (MC) ➔Porphyry ➔Regiomontanus ➔Morinus ➔Alcabatius ➔Campanus ➔Meridian ➔Vehlow ➔Meridian

In this post, however, I will give my own argument on why I use whole signs and why I disagree with placidus. If you disagree with me thats fine, but I hope to at least educate on how these house systems even work and the deeper meaning behind why using whole signs is improtant.

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First, how does Placidus work?

The ascendant (as well as the dsc, mc, ic) is a mathematical point based on the on the sign on the Eastern horizon. Placidus works by marking the cusps of the houses into two-hour intervals starting from the time of your birth. This is then pushed every 2 hours for the 12th 11th 10th 9th 8th and 7th house cusps ( because by the 7th house cusp it has completed 6/6 of its daily solar arc ) and then mirrored for the houses below (already an...interesting method). It is a quadrant system.

How does Whole Signs (WS) work?

Whole signs is not a time based system like Placidus. Whole signs split the houses into equal 30 degree segments, much like how the zodiac signs are split, so each house is equal in size and all the signs start at 0 degrees. The ascendant point, MC, IC, and DC float within the house instead.

Main issues:

Historical

➥The maths for this was laid out by Ptolemy for the purpose of understanding primary directions, of which most people now believe was actually used to predict lifespan - not for a house system. And then eventually an astrologer called Abraham ibn Ezra interpreted Ptolemy's works as a house system which Placidus then came along and validated. ➥During the 17th century British astrologers took this and ran. The Church did not like Placidus' works and so the astrologers essentially pushed the system as revenge against the Church/a big F you to them, making it the popularised system to use. This sacrified accuracy. Placidus rests on a foudnation not even designed to be a house system in the first place which creates a lot of problems as we will see below. P.S. I would HIGHLY recommend reading this article on the popularisation of placidus for a more indepth, better explanation.

Functional

➥Placidus simply falls apart at extreme latitudes (which people ARE born at). Take this chart for example:

Is everyone born at extreme latiudes suddenly inherently special for having such a chart where the houses are so vastly unequal and inutile in size? How does one go about interpreting the significance of this? Houses are literally swallowed up/duplicated or are massive or tiny. Just because your houses might not change so much in WS or placidus does not mean its still valid - a house system has to work for everybody universally. In WS however:

This works and makes SENSE. It is not an issue of being able to interpret the so-called intercepted house (which placidus has the issue of as the maths for it was never intended to be a house system in the first place) or not, it is about being accurate in how to read a chart. ➥Notice how in the placidus chart it appears the ascendant is in the 12th house. This is another visual issue with placidus, for instance apps like CoStar will even tell you that your ascendant is in the 12th house... Placidus or not though the ascendant is always in or at the first house, the ascendant can never be in any other house - the 1st house is literally YOU. The cusps just looked messed up because of the intercepted houses. And chart generating platforms like CoStar relying on placidus mess up even further...

➥ Intercepted houses mean a sign/s is "swallowed up" and doesn't influence any house cusp, which contradicts the principle that every zodiac sign has a clear role in the chart (every house and sign matters whether or not a house is empty etc). The idea that a sign is somehow blocked or inaccessible is untrue, whether or not you think it relates to you (certain aspects in your chart for explain that feeling when read properly rather than this, either way astrology does not care about how you feel or how you wish your chart was; many people get upset that their sun sign moves from the 5th to 6th house for example in WS).

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Rebutting common arguments for placidus

"Whole signs doesn't take into account the rotation and curvature of the earth!"

✣First, as explained above, WS houses remain consistent regardless of the observer's latitude, avoiding the distortions and inaccuracies systems like Placidus introduce, particularly at extreme latitudes. WS houses rely on the zodiac's natural, unchanging divisions, which are independent of the Earth's curvature and geographic location (as explained in this post), providing consistent and straightforward house boundaries. ✣WS matches the universe's system. The signs, and therefore the houses are all about the sun rising from zero (its declination/ going from 0 degrees of whatever sign up till 29 and into the next) as the system follows every 30 degree section of the ecliptic , and correlates with the length of the sign's period. If the ascendant involves the ecliptic meeting the horizon , the ascendant point is a specific coordinate that is located within the first house whose cusp starts at 0 rather than marking the beginning of the cusp. Why should the house system not match what is going on above from which we observe and practise.

"Why not a time-based system if astrology is all about predictive techniques and seems so time sensitive?"

✣ Time doesn't exist in space in the same way it does here, time is just our tool to pinpoint moments against a measurement from which we can organise things (generally speaking). Time is, however, crucial for predictions only in how translate what happens up there to below, less so for diving the sky which is basically already divided for us. ✣ Time-based divisions, like placidus, introduce unnecessary complexity without adding real astrological value, as the essential qualities of the houses are fully captured by the zodiac's natural 30-degree segments in WS anyway as explained above.

"The MC and IC cannot be in houses which are not 10th and 4th!"

✣ Yes they can, this is quite straightforward. In WS, the IC can be in the 2nd-6th house and MC in 8th-12th (extremely rarely it can be in the 1st/7th house too). It is a floating mathematical point (like the asc and dsc) and does not mark the beginning of the 4th house and 10th house cusps like in Placidus. ✣ This is because the MC is the point where the sun culminates at its highest position in the sky at a given location, corresponding to the local meridian. The IC is directly opposite, marking the lowest point below the horizon. The MC and IC are not tied to the zodiac signs but are based on the intersection of the ecliptic (the Sun's apparent path) with the meridian line of the observer's location. This intersection varies based on the time of birth and latitude, and these points can occur at any degree of the zodiac. Because WS houses are aligned with the zodiac signs and the MC/IC are specific points along the ecliptic, the MC and IC can fall at different degrees that don't align with the 10th and 4th house cusps. ✣ This adds more nuance to readings. For instance, if the MC is in the 9th house instead of the 10th, it might indicate that one's career/public life/legacy/how they come off is strongly influenced by 9th house themes like higher education, travel, or philosophy. Thus, they add more information to how 10th and 4th house themes manifest. ✣ Here is a must-read article if you want more information (thorough analysis of MC/IC through the houses) on this topic: Patrick Watson- What To Do When the Midheaven Is Not in the 10th Whole Sign House.

Ending thoughts

People find it difficult to move on from placidus because they think their placidus charts makes complete sense/they resonate deeply with it/ they simply prefer their house placements in placidus to WS. All this is because of, for lack of better wording, a skill issue. You think it makes more sense but thats because you don't actually know how to properly delineate a chart - end of. And that's fine, astrology is complex and interpretation requires a lot of practise and deep study, especially into hellenistic works for a richer understanding of astrology.

Using placidus makes readings and your understanding of astrology unnecessarily complex and undermines the true art of chart intepretation, allowing for pop astrologers to import their own 'psychological' analysis, for instance, onto you via astrology - a deep misuse. Astrology has never been about psychologically explaining yourself - it is a map of your entire life of which you will not always 'relate' to, especially at different points in your life because those energies simply won't be pertinent/obvious when we are 5 vs 50 for example. I have spoken about the problems of using "resonating" to determine the accuracy of your astrological studies in my introductory post already, but it is a point which keeps needing to be re-emphasised.

The Whole Sign system is the oldest of all house systems, used effectively by ancient astrologers for thousands of years. It provides consistent and reliable results, particularly in predictive work, without the unnecessary and inaccurate complications introduced by varying house sizes and interceptions. If you want to use profection charts for instance, or many other traditional techniques, placidus will not work.

Placidus (as well as modern rulerships and the ABC house system which I will make posts on later) will take a while to unlearn - it certainly took me a long time to adjust out of the grips of modern pop culture's inaccurate and misleading yet addictive astrology. This is okay. But at the end of the day, wrong is wrong no matter how you try to justify it.

However, it is your personal choice. Posts like mine can only hope to encourage you to explore the deeper layers of astrology. Things like WS can take a while to accept, or you may never accept it - but as long as you make that decision fully informed. Yours sincerely, an ex-Placidus user xoxo