Index › H › Houses
Houses
Revised 2026-02-04 · Contributors · How entries are written
Houses divide the sky as seen from a particular place at a particular moment; signs divide the ecliptic itself. The two are frequently conflated in introductory material. A chart has both, and a body occupies one sign and one house simultaneously.
Principal systems
- Whole sign
- The sign containing the ascendant becomes the entire first house, the next sign the second, and so on. House cusps coincide with sign boundaries.
- The oldest attested system and widely revived since the late twentieth century.
- Equal
- Each house is thirty degrees, measured from the ascendant degree rather than from the sign boundary.
- Placidus
- A time-based quadrant system dividing the diurnal and nocturnal arcs. The most common default in commercial software.
- Breaks down above roughly 66 degrees of latitude, where some houses cannot be calculated at all.
- Koch
- Another quadrant system, differing from Placidus in the method of division. Popular in central European practice.
- Campanus and Regiomontanus
- Space-based quadrant systems dividing the prime vertical and the celestial equator respectively.
A chart calculated in two house systems will often place a planet in two different houses. Neither result is an error. Any reading that depends on a house placement should state which system produced it.
Angles
- Ascendant
- First house cusp in most systems. See the separate entry.
- Midheaven
- The intersection of the ecliptic with the local meridian. Tenth house cusp in quadrant systems, but not necessarily in whole sign or equal houses, where it may fall in the ninth or eleventh.
- Descendant
- Opposite the ascendant.
- Imum coeli
- Opposite the midheaven.
Latitude limits
Quadrant systems assume the ecliptic crosses the horizon in a manner that fails inside the polar circles. For births at extreme latitudes, whole sign or equal houses are generally used because they remain defined.