Equal Houses

Definition

Equal houses is a way of dividing a chart into its twelve houses where each cusp — each house boundary — falls a flat thirty degrees on from the Ascendant (or sometimes another chart point), so every house is exactly thirty degrees of the zodiac. The difference from whole sign houses is where the boundaries land: in equal houses they sit at the Ascendant's own degree within each sign in turn, not at zero degrees of the sign. The Midheaven is therefore a floating point that need not line up with the 10th cusp.

In Tradition

Astrologers treat equal houses as a long-attested alternative to both the quadrant systems and whole signs. Hand and Holden draw a sharp line between equal houses and whole signs: in equal houses the thirty-degrees-from-Ascendant points are where houses begin, whereas in whole signs those same degrees act as intensity-points inside signs that begin at zero degrees. The system's appeal is its mathematical simplicity, its independence from latitude, and the way it keeps every house an equal twelfth of the zodiac.

In Practice

An astrologer using equal houses begins each house exactly thirty degrees on from the Ascendant degree. Because the method needs only the Ascendant, it works the same way at every latitude — including the polar regions, where Placidus and Koch break down. The Midheaven is worked out separately and treated as a sensitive point that may land in the 9th, 10th, or 11th equal house. Margaret Hone recommended the system, and it was used in twentieth-century British practice through the Faculty of Astrological Studies; it is one of the main alternatives modern textbooks set against Placidus and whole signs.

Historical Origin

Holden links the equal-house system to the earliest documented division — the Sign-House (whole sign) system of the Alexandrian inventors of astrology — and records the twentieth-century English revival beginning around the same time as Walter Koch's post-WWII Birthplace System in Germany. Hand documents the use of equal houses in his own discussion of whole-sign versus equal cusps. The Latin name domus aequales appears in medieval and Renaissance literature, though the system's consistent thirty-degrees-from-Ascendant form rose to prominence in British practice in the mid-twentieth century.

Further Reading

  • James H. Holden, A History of Horoscopic Astrology
  • Robert Hand, Whole Sign Houses
  • Deborah Houlding, The Houses: Temples of the Sky