Synastry Houses: How House Overlays Work

Synastry is a way of comparing two birth charts to describe how their themes meet. Each chart has 12 houses, and each house relates to an area of life. The 1st house covers self, body and first impressions; the 4th house covers home, family and roots; the 7th house concerns partners and one-to-one bonds. A planet in another person's house brings its themes into that area.

An angular house sits on a main chart point, so its themes tend to show clearly and be felt right away; the 1st, 4th, 7th and 10th houses are angular. A succedent house follows an angular house and concerns what people build, keep and sustain; the 2nd, 5th, 8th and 11th houses are succedent. A cadent house comes before an angular one and concerns adjusting, learning and exchanging; the 3rd, 6th, 9th and 12th houses are cadent.

The birth time of the person whose houses are used is needed to place the house cusps. Without that person's birth time, the chart has no houses for this reading. The calculator uses Placidus houses, with Porphyry houses for places too far north or south for Placidus. Each house page gives ten short readings, one for each planet from the Sun to Pluto, so the same house is considered through different planetary themes.