Rotated House Cusps and Point-Based House Options

You select “Fourth cusp at ASC” in Hermes. In another trial, you choose “Sun in the first house.” Both choices can rearrange the houses, but they do not produce the same construction.

Cusp rotation shifts the calculated boundaries together. A point-based house option constructs houses from a selected reference. The first operation preserves the original widths between cusps. The point-based options covered here construct a new set of houses at intervals of 30°.

This guide concerns two separate controls: twelve cusp settings, including Normal, and sixteen point-based choices in the House System menu. Start by identifying which operation you are performing.

For Solar Sign, Fortune and other specialist constructions, see our specialist house options guide.

Rotating the drawing, changing house labels, and changing the calculation

A wheel facing a different direction on screen does not establish that the calculated positions have changed. Read planetary longitudes, cusp degrees and house numbers together.

The first two rows describe general display operations you may encounter in software. They do not introduce additional Hermes buttons or features. The third row describes the calculation effect of the Hermes cusp control.

The twelve cusp settings, including Normal

The Hermes calculation calculates the selected house system, then finds the shared offset that brings your chosen cusp to the Ascendant’s longitude. It applies that offset to every cusp.

Do not read the menu’s “Normal · first cusp at ASC” label as a geometrical rule for every house system. Normal leaves the chosen system’s original boundaries in place, without an additional rotation. Whole Sign, for example, begins at 0° of the rising sign rather than the exact Ascendant degree. Equal and Whole Sign definitions are described in Swiss Ephemeris §6.2.5.

Bring the fourth cusp to the Ascendant

Assume an ASC of 18° Leo and a fourth cusp of 22° Scorpio. The first four illustrative boundaries are listed below. These teaching values are not results from a specified birth chart or a Hermes calculation.

The ASC is 138° and the fourth cusp is 232°. The required offset is:

138° − 232° = −94°.

Subtract 94° from every cusp. If a result is negative, add 360° to place it within the circle.

The first three house widths were 26°, 32° and 36°, and they remain the same after the shift. The fourth cusp now matches the ASC degree. Do not expect the first cusp to remain there too.

We have not changed the astronomical longitude of the Ascendant or the birth time. Moving the house boundaries relative to the planets can change a planet’s house number. Record both the source method and the rotation, for example: “Placidus · fourth cusp at ASC.”

What do the sixteen point-based choices construct?

These House System choices derive houses at 30° intervals from a reference point. Most place the selected point on the first cusp. Vertex and MC use different target cusps.

The codes provide shorthand for the options. Keep the cusp setting at Normal when checking the target boundaries.

Why the seventh cusp for Vertex and the tenth for MC?

For these choices, the first cusp is calculated so that the target point falls on the required boundary. The remaining cusps advance from the first in steps of 30°.

Assume a Vertex of 12° Sagittarius. Its longitude is 252°. The first cusp is 252° + 180° = 432°, which normalises to 12° Gemini. The seventh cusp is 180° opposite the first: 12° Sagittarius. The Vertex is therefore on the seventh cusp.

Assume an MC of 7° Taurus. Its longitude is 37°. The first cusp is 37° + 90° = 127°, or 7° Leo. The tenth cusp lies 270° beyond the first: 127° + 270° = 397°, normalising to 7° Taurus. The MC is on the tenth cusp.

These examples are derived from the definitions. Placing the MC on the tenth cusp does not, by itself, construct Placidus houses; this arrangement builds intermediate cusps at equal intervals of 30°.

Starting from an exact point versus the beginning of its sign

ROT and ROTW describe different constructions in Hermes:

• ROT: Equal houses from the point’s exact longitude, with the Vertex and MC target adjustments described above.
• ROTW: Whole-sign-based houses from the beginning of the sign containing the point.

With the Sun at 8° Capricorn, “Sun in the first house” puts the first cusp at 8° Capricorn. The Solar Sign option covered in the specialist houses guide begins at 0° Capricorn. In Hermes, Solar Sign uses the Sun-based ROTW arrangement.

Referencing the Sun does not make the two first cusps identical. A zodiac transformation that brings the Sun to 0° Aries also concerns expressing longitudes in a new reference, a separate choice from constructing these houses. Record which control you changed.

How should you record the Lunar Nodes and East Point?

The North and South Lunar Nodes are opposite ends of the same nodal axis. Choosing North or South in a point-based arrangement determines which end anchors the first cusp. True Node or Mean Node is a separate calculation preference that determines the nodal longitude used.

For a North Node assumed at 17° Aries, the opposite South Node is at 17° Libra. Constructing a first cusp from each produces origins 180° apart. Keep the node calculation method unchanged when comparing them.

The East Point reference used by Hermes is the Equatorial Ascendant. Do not treat it as another name for the actual ASC or as the point opposite the Vertex. Swiss Ephemeris §6.3 discusses the naming confusion: this ecliptic point corresponds to the Ascendant obtained at geographical latitude 0° for the same local sidereal time. It need not have the same degree as the ASC of your actual chart.

Vertex is also a separate geometrical point. An interpretive meaning assigned to it does not identify the calculation point you used. Record its name and degree rather than simply writing “special point.”

Try two short comparisons in Hermes

Use the synthetic sample 20 March 2000, 12:00:00 UTC, 41° north, 29° east; Gregorian calendar. Verify the time-zone conversion for that date if the form requires local time.

Fix Tropical, True Node, Normal zodiac transformation and Normal coordinate view. The table below plans an exercise; it does not report calculated results.

Compare A with B first. Then return the cusp setting to Normal before examining C–F separately. This avoids changing two controls in the same trial. If a control is unavailable in your selected mode, record that rather than assuming an operation occurred from its label alone.

Include the version, selection, method used and any warning in each record. If a reference point cannot be calculated, do not attribute results from a substitute method to the original choice.

The Hermes Chart Settings guide explains the controls and purposes of saved preferences. Our complete walkthrough provides a way to document a comparison from beginning to end.

When you finish, write more than “I rotated the chart.” “I shifted the Placidus cusps to bring cusp 4 to the ASC” or “I constructed equal houses from the Sun’s exact longitude” gives you an operation you can reproduce.